org.yarnandtail.andhow.load

Class BaseKeyValuePairLoader

java.lang.Object

org.yarnandtail.andhow.load.BaseLoader

org.yarnandtail.andhow.load.BaseKeyValuePairLoader

All Implemented Interfaces:

Loader, ReadLoader

Direct Known Subclasses:

StdMainStringArgsLoader

public abstract class BaseKeyValuePairLoader
extends BaseLoader
implements ReadLoader

An abstract Loader for use where properties are passed as an array of strings, each of the form name[delimiter]value.

To implement a non-abstract class, override the Loader.load(PropertyConfigurationInternal, LoaderEnvironment, ValidatedValuesWithContext) method with a call to load(PropertyConfigurationInternal, List, String) and supply your own list of key-value pair strings. For a simple example, see the StdMainStringArgsLoader.

By default, this loader trims incoming values for String type properties and will throw a RuntimeException if passed unrecognized properties. Both of these behaviours can be changed by modifying the return values of isTrimmingRequiredForStringValues() and isUnknownPropertyAProblem().

Field Summary

Fields

Modifier and Type	Field and Description
static String	KVP_DELIMITER The default delimiter between a key and a value.
protected boolean	unknownPropertyAProblem

Constructor Summary

Constructors

Constructor and Description
BaseKeyValuePairLoader()

Method Summary

Modifier and Type	Method and Description
String	getLoaderDialect() The type dialect of the loader.
String	getLoaderType() The type of the loader, such as JNDI, PropertyFile, SystemProperty, etc..
String	getSpecificLoadDescription() For this particular load, where was info loaded from? This may vary from run to run based on config params.
boolean	isFlaggable() Returns true if this loader supports FlaggableType's.
boolean	isTrimmingRequiredForStringValues() If true, values for string properties are trimmed by the Trimmer of the property they are associated with.
boolean	isUnknownPropertyAProblem() If true, an unrecognized name is considered a problem that will stop application startup.
LoaderValues	load(PropertyConfigurationInternal runtimeDef, List<String> keyValuePairs, String delimiter) Load from the passed list of keyValuePairs using the passed delimiter.
void	setUnknownPropertyAProblem(boolean isAProblem) If true, an unrecognized property name is considered a problem/error.

Methods inherited from class org.yarnandtail.andhow.load.BaseLoader

attemptToAdd, attemptToAdd, attemptToAdd, attemptToAddIfNotDuplicate, createValue, findDuplicateProperty, getClassConfig, getConfigSamplePrinter, getInstanceConfig, mapNametoProperty, releaseResources

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.yarnandtail.andhow.api.Loader

getClassConfig, getConfigSamplePrinter, getInstanceConfig, load, releaseResources

Field Detail

unknownPropertyAProblem

protected boolean unknownPropertyAProblem

KVP_DELIMITER

public static final String KVP_DELIMITER

The default delimiter between a key and a value.

See Also:

Constant Field Values

Constructor Detail

BaseKeyValuePairLoader

public BaseKeyValuePairLoader()

Method Detail

load

public LoaderValues load(PropertyConfigurationInternal runtimeDef,
                         List<String> keyValuePairs,
                         String delimiter)

Load from the passed list of keyValuePairs using the passed delimiter.

Parameters:

runtimeDef - The definition of all known Properties and naming metadata.

keyValuePairs - List of key-value pairs to load from. Each item in the list is assumed to have a name and value separated by the delimiter.

delimiter - The separator between the name and value in each key-value entry.

Returns:

The Property values loaded by this loader and/or the problems discovered while attempting to load those Property values.

getSpecificLoadDescription

public String getSpecificLoadDescription()

Description copied from interface: Loader

For this particular load, where was info loaded from? This may vary from run to run based on config params. For instance, The PropFileLoader will look multiple places to find a properties file. This method should return the actual location it was found. Assume the text is prefixed with "This loader loaded from: ". An example would be "/home/user/config/my-props.properties" No ending punctuation should be used.

Specified by:

getSpecificLoadDescription in interface Loader

Returns:

isTrimmingRequiredForStringValues

public boolean isTrimmingRequiredForStringValues()

Description copied from interface: Loader

If true, values for string properties are trimmed by the Trimmer of the property they are associated with. If false, no trimming is done. Non-String type property values (like Integer or Date type values) are not affected by this. Loaders that read from text files need to trim values to separate white space and carriage returns from the value. Loaders that read from more tightly defined sources, like reading properties from java.lang.System.getProperties(), can assume that trimming has already happened.

Specified by:

isTrimmingRequiredForStringValues in interface Loader

Returns:

isFlaggable

public boolean isFlaggable()

Description copied from interface: Loader

Returns true if this loader supports FlaggableType's.

Loaders that support FlaggableType give special 'is present' meaning to a property being present without a value, similar to a 'nix command line flag. If a Loader supports flags, it should call FlaggableType.parseFlag(String) instead of ValueType.parse(String) when a Property's ValueType is a FlaggableType. See FlagProp for an example type.

Note: Returning true from this method is only potentially applicable to Loaders that parse strings. Loaders that directly load from rich values do not parse, so the loader logic would ignore the value here.

Examples:
Loading a non-null value from the properties file entry 'name = ' would be unexpected, so a properties file Loader should return 'false' here.
However, a command line loader would be expected to support flags, so should return 'true'.

Specified by:

isFlaggable in interface Loader

Returns:

true if this loader support 'nix style flag semantics for FlaggableType Properties.

getLoaderType

public String getLoaderType()

Description copied from interface: Loader

The type of the loader, such as JNDI, PropertyFile, SystemProperty, etc.. The actual return value is arbitrary, but should be consistent between loaders of the same type. The values returned by getLoaderType and getLoaderDialect are used to removed duplicate loader types when printing sample files. If two loader instances are of the same type and dialect, only one will print the sample file.

Specified by:

getLoaderType in interface Loader

Returns:

Must never returns null.

getLoaderDialect

public String getLoaderDialect()

Description copied from interface: Loader

The type dialect of the loader. For property files, this might be either KeyValuePair or xml for example. The actual return value is arbitrary, but should be consistent between loaders of the same type and dialect. The values returned by getLoaderType and getLoaderDialect are used to removed duplicate loader types when printing sample files. If two loader instances are of the same type and dialect, only one will print the sample file.

Specified by:

getLoaderDialect in interface Loader

Returns:

May return null if there is no meaningful dialect for this type.

setUnknownPropertyAProblem

public void setUnknownPropertyAProblem(boolean isAProblem)

Description copied from interface: ReadLoader

If true, an unrecognized property name is considered a problem/error.

Specified by:

setUnknownPropertyAProblem in interface ReadLoader

isUnknownPropertyAProblem

public boolean isUnknownPropertyAProblem()

Description copied from interface: ReadLoader

If true, an unrecognized name is considered a problem that will stop application startup. This is a safety feature because a unrecognized property name in a properties file could be a typo. For other property sources, however, like System.properties, there are many non-AndHow related values that are expected to be present, so this rule cannot be enforced.

Specified by:

isUnknownPropertyAProblem in interface ReadLoader

Returns: