org.josql.filters

Class JoSQLFileFilter

java.lang.Object

org.josql.filters.AbstractJoSQLFilter

org.josql.filters.JoSQLFileFilter

All Implemented Interfaces:

FileFilter

public class JoSQLFileFilter
extends AbstractJoSQLFilter
implements FileFilter

A FileFilter that uses a JoSQL statement to provide the filtering. The value returned by the accept(File) method is determined by executing the WHERE clause of a JoSQL statement on each File passed in.

Since this uses a sub-set of the JoSQL functionality certain restrictions apply:

• The SELECT clause is ignored.
• The object defined in the FROM clause must be java.io.File
• EXECUTE ON functions are not supported here since there is no way to get the entire set of objects to work on.
• ORDER BY, GROUP BY, HAVING and LIMIT clauses are ignored.

Examples:

   SELECT *
   FROM   java.io.File
   WHERE  name $LIKE '%.html'
   AND    lastModified > toDateMillis('12-04-2004')
   AND    file
 

Field Summary

Fields inherited from class org.josql.filters.AbstractJoSQLFilter

badQuery, exp, q

Constructor Summary

Constructors

Constructor and Description
JoSQLFileFilter(Query q) Init this file filter with the query already built and parsed.
JoSQLFileFilter(String q) Init this file filter with the query.

Method Summary

Modifier and Type	Method and Description
boolean	accept(File f) Apply the WHERE clause of the statement to the File passed in.
boolean	accept(Object o)
Class	getExpectedClass() Always returns File.

Methods inherited from class org.josql.filters.AbstractJoSQLFilter

clearException, getException, getQuery, setQuery, setQuery

Methods inherited from class java.lang.Object

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

Constructor Detail

JoSQLFileFilter

public JoSQLFileFilter(String q)
                throws QueryParseException

Init this file filter with the query.

Parameters:

q - The query.

Throws:

QueryParseException - If there is an issue with the parsing of the query, or if the FROM class is not File.

JoSQLFileFilter

public JoSQLFileFilter(Query q)
                throws IllegalStateException,
                       QueryParseException

Init this file filter with the query already built and parsed.

Parameters:

q - The query.

Throws:

IllegalStateException - If the Query object has not been parsed.

QueryParseException - If the FROM class is not File.

Method Detail

accept

public boolean accept(Object o)

Specified by:

accept in class AbstractJoSQLFilter

accept

public boolean accept(File f)

Apply the WHERE clause of the statement to the File passed in. If an exception is thrown by the execution of the WHERE clause the Query is marked as "dirty" and the where clause is no longer executed on the passed in files (since it is likely that the WHERE clause will fail for all File objects). You can get access to exception by using: AbstractJoSQLFilter.getException().

Specified by:

accept in interface FileFilter

Parameters:

f - The file to evaluate the WHERE on.

Returns:

true if the WHERE clause evaluates to true.

getExpectedClass

public Class getExpectedClass()

Always returns File.

Specified by:

getExpectedClass in class AbstractJoSQLFilter

Returns:

The file class.