org.plumelib.util

Class UtilPlume

java.lang.Object

org.plumelib.util.UtilPlume

public final class UtilPlume
extends java.lang.Object

Utility functions that do not belong elsewhere in the plume package.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	UtilPlume.NullableStringComparator Same as built-in String comparison, but accept null arguments, and place them at the beginning.
static class	UtilPlume.ObjectComparator Attempt to order Objects.
static class	UtilPlume.WildcardFilter A FilenameFilter that accepts files whose name matches the given wildcard.

Method Summary

Modifier and Type	Method and Description
static java.lang.String	abbreviateNumber(long val) Convert a number into an abbreviation such as "5.00K" for 5000 or "65.0M" for 65000000.
static @Nullable java.lang.String	appendProperty(java.util.Properties p, java.lang.String key, java.lang.String value) Set the property to its previous value concatenated to the given value.
static java.lang.String	backticks(java.util.List<java.lang.String> command) Execute the given command, and return all its output as a string.
static java.lang.String	backticks(java.lang.String... command) Execute the given command, and return all its output as a string.
static java.lang.String	backTrace(java.lang.Throwable t) Return a String representation of the backtrace of the given Throwable.
static java.io.BufferedOutputStream	bufferedFileOutputStream(java.lang.String filename, boolean append) Returns a BufferedOutputStream for the file, accounting for the possibility that the file is compressed.
static java.io.BufferedReader	bufferedFileReader(java.io.File file) Returns a BufferedReader for the file, accounting for the possibility that the file is compressed.
static java.io.BufferedReader	bufferedFileReader(java.io.File file, @Nullable java.lang.String charsetName) Returns a BufferedReader for the file, accounting for the possibility that the file is compressed.
static java.io.BufferedReader	bufferedFileReader(java.lang.String filename) Returns a BufferedReader for the file, accounting for the possibility that the file is compressed.
static java.io.BufferedReader	bufferedFileReader(java.lang.String filename, @Nullable java.lang.String charsetName) Returns a BufferedReader for the file, accounting for the possibility that the file is compressed.
static java.io.BufferedWriter	bufferedFileWriter(java.lang.String filename) Returns a BufferedWriter for the file, accounting for the possibility that the file is compressed.
static java.io.BufferedWriter	bufferedFileWriter(java.lang.String filename, boolean append) Returns a BufferedWriter for the file, accounting for the possibility that the file is compressed.
static boolean	canCreateAndWrite(java.io.File file) Returns true if the file exists and is writable, or if the file can be created.
static int	count(java.lang.String s, int ch) Return the number of times the character appears in the string.
static int	count(java.lang.String s, java.lang.String sub) Return the number of times the second string appears in the first.
static long	countLines(java.lang.String filename) Count the number of lines in the specified file.
static java.io.File	createTempDir(java.lang.String prefix, java.lang.String suffix) Creates an empty directory in the default temporary-file directory, using the given prefix and suffix to generate its name.
static boolean	deleteDir(java.io.File dir) Deletes the directory at dir and all its files.
static boolean	deleteDir(java.lang.String dirName) Deletes the directory at dirName and all its files.
static boolean	equalFiles(java.lang.String file1, java.lang.String file2) Return true iff files have the same contents.
static boolean	equalFiles(java.lang.String file1, java.lang.String file2, boolean trimLines) Return true iff the files have the same contents.
static java.lang.String	escapeNonASCII(java.lang.String orig) Escape unprintable characters in the target, following the usual Java backslash conventions, so that the result is sure to be printable ASCII.
static java.lang.String	escapeNonJava(java.lang.Character ch) Like escapeNonJava(String), but for a single character.
static java.lang.String	escapeNonJava(java.lang.String orig) Escape \, ", newline, and carriage-return characters in the target as \\, \", \n, and \r; return a new string if any modifications were necessary.
static java.io.File	expandFilename(java.io.File name) Does tilde expansion on a file name (to the user's home directory).
static java.lang.String	expandFilename(java.lang.String name) Does tilde expansion on a file name (to the user's home directory).
static java.io.InputStream	fileInputStream(java.io.File file) Returns an InputStream for the file, accounting for the possibility that the file is compressed.
static java.io.InputStream	fileInputStream(java.nio.file.Path path) Returns an InputStream for the file, accounting for the possibility that the file is compressed.
static java.util.List<java.lang.String>	fileLines(java.lang.String filename) Return the contents of the file, as a list of strings, one per line.
static java.io.InputStreamReader	fileReader(java.io.File file) Returns a Reader for the file, accounting for the possibility that the file is compressed.
static java.io.InputStreamReader	fileReader(java.io.File file, @Nullable java.lang.String charsetName) Returns a Reader for the file, accounting for the possibility that the file is compressed.
static java.io.InputStreamReader	fileReader(java.nio.file.Path path) Returns a Reader for the file, accounting for the possibility that the file is compressed.
static java.io.InputStreamReader	fileReader(java.nio.file.Path path, @Nullable java.lang.String charsetName) Returns a Reader for the file, accounting for the possibility that the file is compressed.
static java.io.InputStreamReader	fileReader(java.lang.String filename) Returns a Reader for the file, accounting for the possibility that the file is compressed.
static int	hash(double x) Return a hash of the arguments.
static int	hash(double[] a) Return a hash of the arguments.
static int	hash(double[] a, double[] b) Return a hash of the arguments.
static int	hash(double a, double b) Return a hash of the arguments.
static int	hash(double a, double b, double c) Return a hash of the arguments.
static int	hash(long l) Return a hash of the arguments.
static int	hash(long[] a) Return a hash of the arguments.
static int	hash(long[] a, long[] b) Return a hash of the arguments.
static int	hash(long a, long b) Return a hash of the arguments.
static int	hash(long a, long b, long c) Return a hash of the arguments.
static int	hash(@Nullable java.lang.String a) Return a hash of the arguments.
static int	hash(@Nullable java.lang.String[] a) Return a hash of the arguments.
static int	hash(@Nullable java.lang.String a, @Nullable java.lang.String b) Return a hash of the arguments.
static int	hash(@Nullable java.lang.String a, @Nullable java.lang.String b, @Nullable java.lang.String c) Return a hash of the arguments.
static java.lang.String	inferLineSeparator(java.io.File file) Tries to infer the line separator used in a file.
static java.lang.String	inferLineSeparator(java.lang.String filename) Tries to infer the line separator used in a file.
static int	intersectionCardinality(java.util.BitSet a, java.util.BitSet b) Returns the cardinality of the intersection of the two BitSets.
static int	intersectionCardinality(java.util.BitSet a, java.util.BitSet b, java.util.BitSet c) Returns the cardinality of the intersection of the three BitSets.
static boolean	intersectionCardinalityAtLeast(java.util.BitSet a, java.util.BitSet b, java.util.BitSet c, int i) Returns true if the cardinality of the intersection of the three BitSets is at least the given value.
static boolean	intersectionCardinalityAtLeast(java.util.BitSet a, java.util.BitSet b, int i) Returns true if the cardinality of the intersection of the two BitSets is at least the given value.
static java.lang.String	javaSource(java.io.File name) Return a string version of the filename that can be used in Java source.
static java.lang.String	join(java.lang.Iterable<? extends java.lang.Object> v, java.lang.String delim) Concatenate the string representations of the objects, placing the delimiter between them.
static java.lang.String	join(java.lang.Object[] a, java.lang.String delim) Concatenate the string representations of the array elements, placing the delimiter between them.
static java.lang.String	joinLines(java.util.List<java.lang.String> v) Concatenate the string representations of the objects, placing the system-specific line separator between them.
static java.lang.String	joinLines(java.lang.Object... a) Concatenate the string representations of the objects, placing the system-specific line separator between them.
static java.io.LineNumberReader	lineNumberFileReader(java.io.File file) Returns a LineNumberReader for the file, accounting for the possibility that the file is compressed.
static java.io.LineNumberReader	lineNumberFileReader(java.lang.String filename) Returns a LineNumberReader for the file, accounting for the possibility that the file is compressed.
static java.lang.String	lpad(java.lang.String s, int length) Returns a string of the specified length, truncated if necessary, and padded with spaces to the left if necessary.
static java.lang.String	nplural(int n, java.lang.String noun) Return either "n noun" or "n nouns" depending on n.
static boolean	propertyIsTrue(java.util.Properties p, java.lang.String key) Determines whether a property has value "true", "yes", or "1".
static java.lang.String	readerContents(java.io.Reader r) Reads the entire contents of the reader and returns it as a string.
static java.lang.String	readFile(java.io.File file) Reads the entire contents of the file and returns it as a string.
static java.lang.Object	readObject(java.io.File file) Reads an Object from a File.
static java.lang.String	removeWhitespaceAfter(java.lang.String arg, java.lang.String delimiter) Remove all whitespace after instances of delimiter.
static java.lang.String	removeWhitespaceAround(java.lang.String arg, java.lang.String delimiter) Remove all whitespace before or after instances of delimiter.
static java.lang.String	removeWhitespaceBefore(java.lang.String arg, java.lang.String delimiter) Remove all whitespace before instances of delimiter.
static java.lang.String	replaceString(java.lang.String target, java.lang.String oldStr, java.lang.String newStr) Return a new string which is the text of target with all instances of oldStr replaced by newStr.
static java.lang.String	rpad(double num, int length) Converts the double to a String, then formats it using rpad(String,int).
static java.lang.String	rpad(int num, int length) Converts the int to a String, then formats it using rpad(String,int).
static java.lang.String	rpad(java.lang.String s, int length) Returns a string of the specified length, truncated if necessary, and padded with spaces to the right if necessary.
static @Nullable java.lang.String	setDefaultMaybe(java.util.Properties p, java.lang.String key, java.lang.String value) Set the property only if it was not previously set.
static java.lang.String[]	split(java.lang.String s, char delim) Return an array of Strings representing the characters between successive instances of the delimiter character.
static java.lang.String[]	split(java.lang.String s, java.lang.String delim) Return an array of Strings representing the characters between successive instances of the delimiter String.
static java.lang.String[]	splitLines(java.lang.String s) Return an array of Strings, one for each line in the argument.
static void	streamCopy(java.io.InputStream from, java.io.OutputStream to) Copy the contents of the input stream to the output stream.
static java.util.List<java.lang.String>	streamLines(java.io.InputStream stream) Reads all lines from the stream and returns them in a List<String>.
static java.lang.String	streamString(java.io.InputStream is) Return a String containing all the characters from the input stream.
static java.util.ArrayList<java.lang.Object>	tokens(java.lang.String str) Return a ArrayList of the Strings returned by StringTokenizer.StringTokenizer(String) with the given arguments.
static java.util.ArrayList<java.lang.Object>	tokens(java.lang.String str, java.lang.String delim) Return a ArrayList of the Strings returned by StringTokenizer.StringTokenizer(String,String) with the given arguments.
static java.util.ArrayList<java.lang.Object>	tokens(java.lang.String str, java.lang.String delim, boolean returnDelims) Return a ArrayList of the Strings returned by StringTokenizer.StringTokenizer(String,String,boolean) with the given arguments.
static java.lang.String	unescapeNonJava(java.lang.String orig) Replace "\\", "\"", "\n", and "\r" sequences by their one-character equivalents.
static void	writeFile(java.io.File file, java.lang.String contents) Creates a file with the given name and writes the specified string to it.
static void	writeObject(java.lang.Object o, java.io.File file) Writes an Object to a File.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

intersectionCardinalityAtLeast

@Pure
public static boolean intersectionCardinalityAtLeast(java.util.BitSet a,
                                                           java.util.BitSet b,
                                                           int i)

Returns true if the cardinality of the intersection of the two BitSets is at least the given value.

Parameters:

a - the first BitSet to intersect

b - the second BitSet to intersect

i - the cardinality bound

Returns:

true iff size(a intersect b) ≥ i

intersectionCardinalityAtLeast

@Pure
public static boolean intersectionCardinalityAtLeast(java.util.BitSet a,
                                                           java.util.BitSet b,
                                                           java.util.BitSet c,
                                                           int i)

Returns true if the cardinality of the intersection of the three BitSets is at least the given value.

Parameters:

a - the first BitSet to intersect

b - the second BitSet to intersect

c - the third BitSet to intersect

i - the cardinality bound

Returns:

true iff size(a intersect b intersect c) ≥ i

intersectionCardinality

@Pure
public static int intersectionCardinality(java.util.BitSet a,
                                                java.util.BitSet b)

Returns the cardinality of the intersection of the two BitSets.

Parameters:

a - the first BitSet to intersect

b - the second BitSet to intersect

Returns:

size(a intersect b)

intersectionCardinality

@Pure
public static int intersectionCardinality(java.util.BitSet a,
                                                java.util.BitSet b,
                                                java.util.BitSet c)

Returns the cardinality of the intersection of the three BitSets.

Parameters:

a - the first BitSet to intersect

b - the second BitSet to intersect

c - the third BitSet to intersect

Returns:

size(a intersect b intersect c)

fileInputStream

public static java.io.InputStream fileInputStream(java.nio.file.Path path)
                                           throws java.io.IOException

Returns an InputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

path - the possibly-compressed file to read

Returns:

an InputStream for file

Throws:

java.io.IOException - if there is trouble reading the file

fileInputStream

public static java.io.InputStream fileInputStream(java.io.File file)
                                           throws java.io.IOException

Returns an InputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

file - the possibly-compressed file to read

Returns:

an InputStream for file

Throws:

java.io.IOException - if there is trouble reading the file

fileReader

public static java.io.InputStreamReader fileReader(java.lang.String filename)
                                            throws java.io.FileNotFoundException,
                                                   java.io.IOException

Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

filename - the possibly-compressed file to read

Returns:

an InputStream for filename

Throws:

java.io.IOException - if there is trouble reading the file

java.io.FileNotFoundException - if the file is not found

fileReader

public static java.io.InputStreamReader fileReader(java.nio.file.Path path)
                                            throws java.io.FileNotFoundException,
                                                   java.io.IOException

Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

path - the possibly-compressed file to read

Returns:

an InputStreamReader for file

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

fileReader

public static java.io.InputStreamReader fileReader(java.nio.file.Path path,
                                                   @Nullable java.lang.String charsetName)
                                            throws java.io.FileNotFoundException,
                                                   java.io.IOException

Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

path - the possibly-compressed file to read

charsetName - null, or the name of a Charset to use when reading the file

Returns:

an InputStreamReader for file

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

fileReader

public static java.io.InputStreamReader fileReader(java.io.File file)
                                            throws java.io.FileNotFoundException,
                                                   java.io.IOException

Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

file - the possibly-compressed file to read

Returns:

an InputStreamReader for file

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

fileReader

public static java.io.InputStreamReader fileReader(java.io.File file,
                                                   @Nullable java.lang.String charsetName)
                                            throws java.io.FileNotFoundException,
                                                   java.io.IOException

Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

file - the possibly-compressed file to read

charsetName - null, or the name of a Charset to use when reading the file

Returns:

an InputStreamReader for file

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

bufferedFileReader

public static java.io.BufferedReader bufferedFileReader(java.lang.String filename)
                                                 throws java.io.FileNotFoundException,
                                                        java.io.IOException

Returns a BufferedReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

filename - the possibly-compressed file to read

Returns:

a BufferedReader for file

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

bufferedFileReader

public static java.io.BufferedReader bufferedFileReader(java.io.File file)
                                                 throws java.io.FileNotFoundException,
                                                        java.io.IOException

Returns a BufferedReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

file - the possibility-compressed file to read

Returns:

a BufferedReader for file

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

bufferedFileReader

public static java.io.BufferedReader bufferedFileReader(java.lang.String filename,
                                                        @Nullable java.lang.String charsetName)
                                                 throws java.io.FileNotFoundException,
                                                        java.io.IOException

Returns a BufferedReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

filename - the possibly-compressed file to read

charsetName - the character set to use when reading the file

Returns:

a BufferedReader for filename

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

bufferedFileReader

public static java.io.BufferedReader bufferedFileReader(java.io.File file,
                                                        @Nullable java.lang.String charsetName)
                                                 throws java.io.FileNotFoundException,
                                                        java.io.IOException

Returns a BufferedReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

file - the possibly-compressed file to read

charsetName - the character set to use when reading the file

Returns:

a BufferedReader for file

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

lineNumberFileReader

public static java.io.LineNumberReader lineNumberFileReader(java.lang.String filename)
                                                     throws java.io.FileNotFoundException,
                                                            java.io.IOException

Returns a LineNumberReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

filename - the possibly-compressed file to read

Returns:

a LineNumberReader for filename

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

lineNumberFileReader

public static java.io.LineNumberReader lineNumberFileReader(java.io.File file)
                                                     throws java.io.FileNotFoundException,
                                                            java.io.IOException

Returns a LineNumberReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

file - the possibly-compressed file to read

Returns:

a LineNumberReader for file

Throws:

java.io.FileNotFoundException - if the file cannot be found

java.io.IOException - if there is trouble reading the file

bufferedFileWriter

public static java.io.BufferedWriter bufferedFileWriter(java.lang.String filename)
                                                 throws java.io.IOException

Returns a BufferedWriter for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

filename - the possibly-compressed file to write

Returns:

a BufferedWriter for filename

Throws:

java.io.IOException - if there is trouble writing the file

bufferedFileWriter

public static java.io.BufferedWriter bufferedFileWriter(java.lang.String filename,
                                                        boolean append)
                                                 throws java.io.IOException

Returns a BufferedWriter for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

filename - the possibly-compressed file to write

append - if true, the resulting BufferedWriter appends to the end of the file instead of the beginning

Returns:

a BufferedWriter for filename

Throws:

java.io.IOException - if there is trouble writing the file

bufferedFileOutputStream

public static java.io.BufferedOutputStream bufferedFileOutputStream(java.lang.String filename,
                                                                    boolean append)
                                                             throws java.io.IOException

Returns a BufferedOutputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

Parameters:

filename - the possibly-compressed file to write

append - if true, the resulting BufferedOutputStream appends to the end of the file instead of the beginning

Returns:

a BufferedOutputStream for filename

Throws:

java.io.IOException - if there is trouble writing the file

countLines

public static long countLines(java.lang.String filename)
                       throws java.io.IOException

Count the number of lines in the specified file.

Parameters:

filename - file whose size to count

Returns:

number of lines in filename

Throws:

java.io.IOException - if there is trouble reading the file

fileLines

public static java.util.List<java.lang.String> fileLines(java.lang.String filename)
                                                  throws java.io.IOException

Return the contents of the file, as a list of strings, one per line.

Parameters:

filename - the file whose contents to return

Returns:

the contents of filename, one string per line

Throws:

java.io.IOException - if there was a problem reading the file

inferLineSeparator

public static java.lang.String inferLineSeparator(java.lang.String filename)
                                           throws java.io.IOException

Tries to infer the line separator used in a file.

Parameters:

filename - the file to infer a line separator from

Returns:

the inferred line separator used in filename

Throws:

java.io.IOException - if there is trouble reading the file

inferLineSeparator

public static java.lang.String inferLineSeparator(java.io.File file)
                                           throws java.io.IOException

Tries to infer the line separator used in a file.

Parameters:

file - the file to infer a line separator from

Returns:

the inferred line separator used in filename

Throws:

java.io.IOException - if there is trouble reading the file

equalFiles

@Pure
public static boolean equalFiles(java.lang.String file1,
                                       java.lang.String file2)

Return true iff files have the same contents.

Parameters:

file1 - first file to compare

file2 - second file to compare

Returns:

true iff the files have the same contents

equalFiles

@Pure
public static boolean equalFiles(java.lang.String file1,
                                       java.lang.String file2,
                                       boolean trimLines)

Return true iff the files have the same contents.

Parameters:

file1 - first file to compare

file2 - second file to compare

trimLines - if true, call String.trim on each line before comparing

Returns:

true iff the files have the same contents

canCreateAndWrite

public static boolean canCreateAndWrite(java.io.File file)

Returns true if the file exists and is writable, or if the file can be created.

Parameters:

file - the file to create and write

Returns:

true iff the file can be created and written

createTempDir

public static java.io.File createTempDir(java.lang.String prefix,
                                         java.lang.String suffix)
                                  throws java.io.IOException

Creates an empty directory in the default temporary-file directory, using the given prefix and suffix to generate its name. For example, calling createTempDir("myPrefix", "mySuffix") will create the following directory: temporaryFileDirectory/myUserName/myPrefix_someString_suffix. someString is internally generated to ensure no temporary files of the same name are generated.

Parameters:

prefix - the prefix string to be used in generating the file's name; must be at least three characters long

suffix - the suffix string to be used in generating the file's name; may be null, in which case the suffix ".tmp" will be used Returns: An abstract pathname denoting a newly-created empty file

Returns:

a File representing the newly-created temporary directory

Throws:

java.lang.IllegalArgumentException - If the prefix argument contains fewer than three characters

java.io.IOException - If a file could not be created

java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) method does not allow a file to be created

See Also:

File.createTempFile(String, String, File)

deleteDir

public static boolean deleteDir(java.lang.String dirName)

Deletes the directory at dirName and all its files. Also works on regular files.

Parameters:

dirName - the directory to delete

Returns:

true if and only if the file or directory is successfully deleted; false otherwise

deleteDir

public static boolean deleteDir(java.io.File dir)

Deletes the directory at dir and all its files. Also works on regular files.

Parameters:

dir - the directory to delete

Returns:

true if and only if the file or directory is successfully deleted; false otherwise

expandFilename

public static java.io.File expandFilename(java.io.File name)

Does tilde expansion on a file name (to the user's home directory).

Parameters:

name - file whose name to expand

Returns:

file with expanded file

expandFilename

public static java.lang.String expandFilename(java.lang.String name)

Does tilde expansion on a file name (to the user's home directory).

Parameters:

name - filename to expand

Returns:

expanded filename

javaSource

public static java.lang.String javaSource(java.io.File name)

Return a string version of the filename that can be used in Java source. On Windows, the file will return a backslash separated string. Since backslash is an escape character, it must be quoted itself inside the string.

The current implementation presumes that backslashes don't appear in filenames except as windows path separators. That seems like a reasonable assumption.

Parameters:

name - file whose name to quote

Returns:

a string version of the name that can be used in Java source

writeObject

public static void writeObject(java.lang.Object o,
                               java.io.File file)
                        throws java.io.IOException

Writes an Object to a File.

Parameters:

o - the object to write

file - the file to which to write the object

Throws:

java.io.IOException - if there is trouble writing the file

readObject

public static java.lang.Object readObject(java.io.File file)
                                   throws java.io.IOException,
                                          java.lang.ClassNotFoundException

Reads an Object from a File.

Parameters:

file - the file from which to read

Returns:

the object read from the file

Throws:

java.io.IOException - if there is trouble reading the file

java.lang.ClassNotFoundException - if the object's class cannot be found

readerContents

public static java.lang.String readerContents(java.io.Reader r)

Reads the entire contents of the reader and returns it as a string. Any IOException encountered will be turned into an Error.

Parameters:

r - the Reader to read

Returns:

the entire contents of the reader, as a string

readFile

public static java.lang.String readFile(java.io.File file)

Reads the entire contents of the file and returns it as a string. Any IOException encountered will be turned into an Error.

You could use new String(Files.readAllBytes(...)), but it requires a Path rather than a File, and it can throw IOException which has to be caught.

Parameters:

file - the file to read

Returns:

the entire contents of the reader, as a string

writeFile

public static void writeFile(java.io.File file,
                             java.lang.String contents)

Creates a file with the given name and writes the specified string to it. If the file currently exists (and is writable) it is overwritten Any IOException encountered will be turned into an Error.

Parameters:

file - the file to write to

contents - the text to put in the file

hash

public static int hash(double x)

Return a hash of the arguments. Note that this differs from the result of Double.hashCode().

Parameters:

x - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(double a,
                       double b)

Return a hash of the arguments.

Parameters:

a - value to be hashed

b - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(double a,
                       double b,
                       double c)

Return a hash of the arguments.

Parameters:

a - value to be hashed

b - value to be hashed

c - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(double[] a)

Return a hash of the arguments.

Parameters:

a - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(double[] a,
                       double[] b)

Return a hash of the arguments.

Parameters:

a - value to be hashed

b - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(long l)

Return a hash of the arguments. Note that this differs from the result of Long.hashCode(). But it doesn't map -1 and 0 to the same value.

Parameters:

l - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(long a,
                       long b)

Return a hash of the arguments.

Parameters:

a - value to be hashed

b - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(long a,
                       long b,
                       long c)

Return a hash of the arguments.

Parameters:

a - value to be hashed

b - value to be hashed

c - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(long[] a)

Return a hash of the arguments.

Parameters:

a - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(long[] a,
                       long[] b)

Return a hash of the arguments.

Parameters:

a - value to be hashed

b - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(@Nullable java.lang.String a)

Return a hash of the arguments.

Parameters:

a - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(@Nullable java.lang.String a,
                       @Nullable java.lang.String b)

Return a hash of the arguments.

Parameters:

a - value to be hashed

b - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(@Nullable java.lang.String a,
                       @Nullable java.lang.String b,
                       @Nullable java.lang.String c)

Return a hash of the arguments.

Parameters:

a - value to be hashed

b - value to be hashed

c - value to be hashed

Returns:

a hash of the arguments

hash

public static int hash(@Nullable java.lang.String[] a)

Return a hash of the arguments.

Parameters:

a - value to be hashed

Returns:

a hash of the arguments

backticks

public static java.lang.String backticks(java.lang.String... command)

Execute the given command, and return all its output as a string.

Parameters:

command - a command to execute on the command line

Returns:

all the output of the command

backticks

public static java.lang.String backticks(java.util.List<java.lang.String> command)

Execute the given command, and return all its output as a string.

Parameters:

command - a command to execute on the command line, as a list of strings (the command, then its arguments)

Returns:

all the output of the command

propertyIsTrue

@Pure
public static boolean propertyIsTrue(java.util.Properties p,
                                           java.lang.String key)

Determines whether a property has value "true", "yes", or "1".

Parameters:

p - a Properties object in which to look up the property

key - name of the property to look up

Returns:

true iff the property has value "true", "yes", or "1"

See Also:

Properties.getProperty(java.lang.String)

appendProperty

public static @Nullable java.lang.String appendProperty(java.util.Properties p,
                                                        java.lang.String key,
                                                        java.lang.String value)

Set the property to its previous value concatenated to the given value. Return the previous value.

Parameters:

p - a Properties object in which to look up the property

key - name of the property to look up

value - value to concatenate to the previous value of the property

Returns:

the previous value of the property

See Also:

Properties.getProperty(java.lang.String), Properties.setProperty(java.lang.String, java.lang.String)

setDefaultMaybe

public static @Nullable java.lang.String setDefaultMaybe(java.util.Properties p,
                                                         java.lang.String key,
                                                         java.lang.String value)

Set the property only if it was not previously set.

Parameters:

p - a Properties object in which to look up the property

key - name of the property to look up

value - value to set the property to, if it is not already set

Returns:

the previous value of the property

See Also:

Properties.getProperty(java.lang.String), Properties.setProperty(java.lang.String, java.lang.String)

streamCopy

public static void streamCopy(java.io.InputStream from,
                              java.io.OutputStream to)

Copy the contents of the input stream to the output stream.

Parameters:

from - input stream

to - output stream

streamString

public static java.lang.String streamString(java.io.InputStream is)

Return a String containing all the characters from the input stream.

Parameters:

is - input stream to read

Returns:

a String containing all the characters from the input stream

streamLines

public static java.util.List<java.lang.String> streamLines(java.io.InputStream stream)
                                                    throws java.io.IOException

Reads all lines from the stream and returns them in a List<String>.

Parameters:

stream - the stream to read from

Returns:

the list of lines read from the stream

Throws:

java.io.IOException - if there is an error reading from the stream

replaceString

public static java.lang.String replaceString(java.lang.String target,
                                             java.lang.String oldStr,
                                             java.lang.String newStr)

Return a new string which is the text of target with all instances of oldStr replaced by newStr.

Parameters:

target - the string to do replacement in

oldStr - the substring to replace

newStr - the replacement

Returns:

target with all instances of oldStr replaced by newStr

split

public static java.lang.String[] split(java.lang.String s,
                                       char delim)

Return an array of Strings representing the characters between successive instances of the delimiter character. Always returns an array of length at least 1 (it might contain only the empty string).

Consider using the built-in String.split method.

Parameters:

s - the string to split

delim - delimiter to split the string on

Returns:

array of length at least 1, containing s split on delimiter

See Also:

split(String s, String delim)

split

public static java.lang.String[] split(java.lang.String s,
                                       java.lang.String delim)

Return an array of Strings representing the characters between successive instances of the delimiter String. Always returns an array of length at least 1 (it might contain only the empty string).

Consider using the built-in String.split method.

Parameters:

s - the string to split

delim - delimiter to split the string on

Returns:

array of length at least 1, containing s split on delimiter

See Also:

split(String s, char delim)

splitLines

@SideEffectFree
public static java.lang.String[] splitLines(java.lang.String s)

Return an array of Strings, one for each line in the argument. Always returns an array of length at least 1 (it might contain only the empty string). All common line separators (cr, lf, cr-lf, or lf-cr) are supported. Note that a string that ends with a line separator will return an empty string as the last element of the array.

Parameters:

s - the string to split

Returns:

an array of Strings, one for each line in the argument

See Also:

split(String s, char delim)

join

public static java.lang.String join(java.lang.Object[] a,
                                    java.lang.String delim)

Concatenate the string representations of the array elements, placing the delimiter between them.

If you are using Java 8 or later, then use the String.join() method instead.

Parameters:

a - array of values to concatenate

delim - delimiter to place between printed representations

Returns:

the concatenation of the string representations of the values, with the delimiter between

joinLines

public static java.lang.String joinLines(java.lang.Object... a)

Concatenate the string representations of the objects, placing the system-specific line separator between them.

Parameters:

a - array of values to concatenate

Returns:

the concatenation of the string representations of the values, each on its own line

join

public static java.lang.String join(java.lang.Iterable<? extends java.lang.Object> v,
                                    java.lang.String delim)

Concatenate the string representations of the objects, placing the delimiter between them.

Parameters:

v - collection of values to concatenate

delim - delimiter to place between printed representations

Returns:

the concatenation of the string representations of the values, with the delimiter between

See Also:

AbstractCollection.toString()

joinLines

public static java.lang.String joinLines(java.util.List<java.lang.String> v)

Concatenate the string representations of the objects, placing the system-specific line separator between them.

Parameters:

v - list of values to concatenate

Returns:

the concatenation of the string representations of the values, each on its own line

See Also:

AbstractCollection.toString()

escapeNonJava

public static java.lang.String escapeNonJava(java.lang.String orig)

Escape \, ", newline, and carriage-return characters in the target as \\, \", \n, and \r; return a new string if any modifications were necessary. The intent is that by surrounding the return value with double quote marks, the result will be a Java string literal denoting the original string.

Parameters:

orig - string to quote

Returns:

quoted version of orig

escapeNonJava

public static java.lang.String escapeNonJava(java.lang.Character ch)

Like escapeNonJava(String), but for a single character.

Parameters:

ch - character to quote

Returns:

quoted version och ch

escapeNonASCII

public static java.lang.String escapeNonASCII(java.lang.String orig)

Escape unprintable characters in the target, following the usual Java backslash conventions, so that the result is sure to be printable ASCII. Returns a new string.

Parameters:

orig - string to quote

Returns:

quoted version of orig

unescapeNonJava

public static java.lang.String unescapeNonJava(java.lang.String orig)

Replace "\\", "\"", "\n", and "\r" sequences by their one-character equivalents. All other backslashes are removed (for instance, octal/hex escape sequences are not turned into their respective characters). This is the inverse operation of escapeNonJava(java.lang.String), but it is not a general unescaping mechanism for Java strings.

Parameters:

orig - string to quote

Returns:

quoted version of orig

removeWhitespaceAround

public static java.lang.String removeWhitespaceAround(java.lang.String arg,
                                                      java.lang.String delimiter)

Remove all whitespace before or after instances of delimiter.

Parameters:

arg - string to remove whitespace in

delimiter - string to remove whitespace abutting

Returns:

version of arg, with whitespace abutting delimiter removed

removeWhitespaceAfter

public static java.lang.String removeWhitespaceAfter(java.lang.String arg,
                                                     java.lang.String delimiter)

Remove all whitespace after instances of delimiter.

Parameters:

arg - string to remove whitespace in

delimiter - string to remove whitespace after

Returns:

version of arg, with whitespace after delimiter removed

removeWhitespaceBefore

public static java.lang.String removeWhitespaceBefore(java.lang.String arg,
                                                      java.lang.String delimiter)

Remove all whitespace before instances of delimiter.

Parameters:

arg - string to remove whitespace in

delimiter - string to remove whitespace before

Returns:

version of arg, with whitespace before delimiter removed

nplural

public static java.lang.String nplural(int n,
                                       java.lang.String noun)

Return either "n noun" or "n nouns" depending on n. Adds "es" to words ending with "ch", "s", "sh", or "x".

Parameters:

n - count of nouns

noun - word being counted

Returns:

noun, if n==1; otherwise, pluralization of noun

lpad

public static java.lang.String lpad(java.lang.String s,
                                    int length)

Returns a string of the specified length, truncated if necessary, and padded with spaces to the left if necessary.

Parameters:

s - string to truncate or pad

length - goal length

Returns:

s truncated or padded to length characters

rpad

public static java.lang.String rpad(java.lang.String s,
                                    int length)

Returns a string of the specified length, truncated if necessary, and padded with spaces to the right if necessary.

Parameters:

s - string to truncate or pad

length - goal length

Returns:

s truncated or padded to length characters

rpad

public static java.lang.String rpad(int num,
                                    int length)

Converts the int to a String, then formats it using rpad(String,int).

Parameters:

num - int whose string representation to truncate or pad

length - goal length

Returns:

a string representation of num truncated or padded to length characters

rpad

public static java.lang.String rpad(double num,
                                    int length)

Converts the double to a String, then formats it using rpad(String,int).

Parameters:

num - double whose string representation to truncate or pad

length - goal length

Returns:

a string representation of num truncated or padded to length characters

count

public static int count(java.lang.String s,
                        int ch)

Return the number of times the character appears in the string.

Parameters:

s - string to search in

ch - character to search for

Returns:

number of times the character appears in the string

count

public static int count(java.lang.String s,
                        java.lang.String sub)

Return the number of times the second string appears in the first.

Parameters:

s - string to search in

sub - non-empty string to search for

Returns:

number of times the substring appears in the string

abbreviateNumber

public static java.lang.String abbreviateNumber(long val)

Convert a number into an abbreviation such as "5.00K" for 5000 or "65.0M" for 65000000. K stands for 1000, not 1024; M stands for 1000000, not 1048576, etc. There are always exactly 3 decimal digits of precision in the result (counting both sides of the decimal point).

Parameters:

val - a numeric value

Returns:

an abbreviated string representation of the value

tokens

public static java.util.ArrayList<java.lang.Object> tokens(java.lang.String str,
                                                           java.lang.String delim,
                                                           boolean returnDelims)

Return a ArrayList of the Strings returned by StringTokenizer.StringTokenizer(String,String,boolean) with the given arguments.

The static type is ArrayList<Object> because StringTokenizer extends Enumeration<Object> instead of Enumeration<String> as it should (probably due to backward-compatibility).

Parameters:

str - a string to be parsed

delim - the delimiters

returnDelims - flag indicating whether to return the delimiters as tokens

Returns:

vector of strings resulting from tokenization

tokens

public static java.util.ArrayList<java.lang.Object> tokens(java.lang.String str,
                                                           java.lang.String delim)

Return a ArrayList of the Strings returned by StringTokenizer.StringTokenizer(String,String) with the given arguments.

Parameters:

str - a string to be parsed

delim - the delimiters

Returns:

vector of strings resulting from tokenization

tokens

public static java.util.ArrayList<java.lang.Object> tokens(java.lang.String str)

Return a ArrayList of the Strings returned by StringTokenizer.StringTokenizer(String) with the given arguments.

Parameters:

str - a string to be parsed

Returns:

vector of strings resulting from tokenization

backTrace

public static java.lang.String backTrace(java.lang.Throwable t)

Return a String representation of the backtrace of the given Throwable. To see a backtrace at the the current location, do backtrace(new Throwable()).

Parameters:

t - the Throwable to obtain a backtrace of

Returns:

a String representation of the backtrace of the given Throwable