net.sf.mmm.util.transformer.base
Class StringTransformerChain

java.lang.Object
  net.sf.mmm.util.transformer.base.StringTransformerChain

All Implemented Interfaces:

Transformer<String>

public class StringTransformerChain
extends Object
implements Transformer<String>

This class represents a Transformer for Strings that is build out of a list of rules. It performs its transformation by passing the given value to the first rule and its result to the next rule and so on. If a rule matched, it can stop further proceeding via the stop-on-match flag and cause its result to be returned immediately. Otherwise the result of the last rule in the chain is returned (like a left associative operator).

Since:

1.0.2

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

Nested Class Summary

protected static class

StringTransformerChain.State This inner class contains the state of a transformation.

Field Summary

private String	id
private StringTransformerChain	parent The parent that is extended by this chain or null.
private StringTransformerRule[]	rules The rules of this chain.

Constructor Summary

StringTransformerChain()
The non-arg constructor.

StringTransformerChain(String id, StringTransformerChain parent, StringTransformerRule... rules)
The constructor.

StringTransformerChain(StringTransformerRule... rules)
The constructor.

Method Summary

StringTransformerChain	extend(StringTransformerRule... additionalRules) This method extends this chain with additionalRules.
String	getId() This method gets the ID used to identify this chain.
String	transform(String original) This method transforms a given original value.
private String	transformRecursive(String original, StringTransformerChain.State state) This method implements transform(String) recursively.

Methods inherited from class java.lang.Object

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

Field Detail

id

private String id

See Also:

getId()

parent

private StringTransformerChain parent

The parent that is extended by this chain or null.

rules

private StringTransformerRule[] rules

The rules of this chain.

Constructor Detail

StringTransformerChain

public StringTransformerChain()

The non-arg constructor.
NOTE:
This constructor should not be called directly! It is only intended for reflective access (e.g. for JAXB).

StringTransformerChain

public StringTransformerChain(StringTransformerRule... rules)

The constructor.

Parameters:

rules - are the rules of this chain.

StringTransformerChain

public StringTransformerChain(String id,
                              StringTransformerChain parent,
                              StringTransformerRule... rules)

The constructor.

Parameters:

id - the ID of this chain.

parent - is the parent chain to extend or null for a root-chain.

rules - are the rules of this chain.

Method Detail

transform

public String transform(String original)

This method transforms a given original value. This value must NOT be modified by this method. To change the original value a new value has to be created and returned instead. If the value should NOT be changed, the original value (the exact same instance) should be returned.

Specified by:

transform in interface Transformer<String>

Parameters:

original - is the original value.

Returns:

the transformed value. May only be null if explicitly documented by the implementation. The receiver of a Transformer should also document if null is a legal result.

transformRecursive

private String transformRecursive(String original,
                                  StringTransformerChain.State state)

This method implements transform(String) recursively.

Parameters:

original - is the original value.

state - is the StringTransformerChain.State used to indicate if a rule causes the chain to StringTransformerChain.State.stop.

Returns:

the transformed result.

getId

public String getId()

This method gets the ID used to identify this chain.

Returns:

the ID or null if undefined.

extend

public StringTransformerChain extend(StringTransformerRule... additionalRules)

This method extends this chain with additionalRules.
ATTENTION:
If you want to be able to marshall the chain with JAXB, you have to use StringTransformerChain(String, StringTransformerChain, StringTransformerRule...) instead.

Parameters:

additionalRules - are the rules to add.

Returns:

the chain that also checks the additionalRules if none of this rules match.