org.simpleframework.xml.transform.StringArrayTransform Maven / Gradle / Ivy
/*
* StringArrayTransform.java May 2007
*
* Copyright (C) 2007, Niall Gallagher
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
package org.simpleframework.xml.transform;
import org.simpleframework.xml.transform.Transform;
import java.util.regex.Pattern;
/**
* The StringArrayTransform is used to transform string
* arrays to and from string representations, which will be inserted
* in the generated XML document as the value place holder. The
* value must be readable and writable in the same format. Fields
* and methods annotated with the XML attribute annotation will use
* this to persist and retrieve the value to and from the XML source.
*
*
* @Attribute
* private String[] array;
*
*
* As well as the XML attribute values using transforms, fields and
* methods annotated with the XML element annotation will use this.
* Aside from the obvious difference, the element annotation has an
* advantage over the attribute annotation in that it can maintain
* any references using the CycleStrategy object.
*
* @author Niall Gallagher
*/
class StringArrayTransform implements Transform {
/**
* Represents the pattern used to split the string values.
*/
private final Pattern pattern;
/**
* This is the token used to split the string into an array.
*/
private final String token;
/**
* Constructor for the StringArrayTransform object.
* This will create a transform that will split an array using a
* comma as the delimeter. In order to perform the split in a
* reasonably performant manner the pattern used is compiled.
*/
public StringArrayTransform() {
this(",");
}
/**
* Constructor for the StringArrayTransform object.
* This will create a transform that will split an array using a
* specified regular expression pattern. To keep the performance
* of the transform reasonable the pattern used is compiled.
*
* @param token the pattern used to split the string values
*/
public StringArrayTransform(String token) {
this.pattern = Pattern.compile(token);
this.token = token;
}
/**
* This method is used to convert the string value given to an
* appropriate representation. This is used when an object is
* being deserialized from the XML document and the value for
* the string representation is required.
*
* @param value this is the string representation of the value
*
* @return this returns an appropriate instanced to be used
*/
public String[] read(String value) {
return read(value, token);
}
/**
* This method is used to convert the string value given to an
* appropriate representation. This is used when an object is
* being deserialized from the XML document and the value for
* the string representation is required.
*
* @param value this is the string representation of the value
* @param token this is the token used to split the string
*
* @return this returns an appropriate instanced to be used
*/
private String[] read(String value, String token) {
String[] list = pattern.split(value);
for(int i = 0; i < list.length; i++) {
String text = list[i];
if(text != null) {
list[i] = text.trim();
}
}
return list;
}
/**
* This method is used to convert the provided value into an XML
* usable format. This is used in the serialization process when
* there is a need to convert a field value in to a string so
* that that value can be written as a valid XML entity.
*
* @param list this is the value to be converted to a string
*
* @return this is the string representation of the given value
*/
public String write(String[] list) {
return write(list, token);
}
/**
* This method is used to convert the provided value into an XML
* usable format. This is used in the serialization process when
* there is a need to convert a field value in to a string so
* that that value can be written as a valid XML entity.
*
* @param list this is the value to be converted to a string
* @param token this is the token used to join the strings
*
* @return this is the string representation of the given value
*/
private String write(String[] list, String token) {
StringBuilder text = new StringBuilder();
for(int i = 0; i < list.length; i++) {
String item = list[i];
if(item != null) {
if(text.length() > 0) {
text.append(token);
text.append(' ');
}
text.append(item);
}
}
return text.toString();
}
}