NamedArrayConverter.java
/*
* Copyright (C) 2013, 2014, 2015, 2018 XStream Committers.
* All rights reserved.
*
* The software in this package is published under the terms of the BSD
* style license a copy of which has been included with this distribution in
* the LICENSE.txt file.
*
* Created on 03. December 2013 by Joerg Schaible
*/
package com.thoughtworks.xstream.converters.extended;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.List;
import com.thoughtworks.xstream.converters.Converter;
import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.core.util.HierarchicalStreams;
import com.thoughtworks.xstream.core.util.Primitives;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.mapper.Mapper;
/**
* An array converter that uses predefined names for its items.
* <p>
* To be used as local converter.
* </p>
*
* @author Jörg Schaible
* @since 1.4.6
*/
public class NamedArrayConverter implements Converter {
private final Class<?> arrayType;
private final String itemName;
private final Mapper mapper;
/**
* Construct a NamedArrayConverter.
*
* @param arrayType
* @param mapper
* @param itemName
* @since 1.4.6
*/
public NamedArrayConverter(final Class<?> arrayType, final Mapper mapper, final String itemName) {
if (!arrayType.isArray()) {
throw new IllegalArgumentException(arrayType.getName() + " is not an array");
}
this.arrayType = arrayType;
this.mapper = mapper;
this.itemName = itemName;
}
@Override
public boolean canConvert(final Class<?> type) {
return type == arrayType;
}
@Override
public void marshal(final Object source, final HierarchicalStreamWriter writer, final MarshallingContext context) {
final int length = Array.getLength(source);
for (int i = 0; i < length; ++i) {
final Object item = Array.get(source, i);
final Class<?> itemType = item == null
? Mapper.Null.class
: arrayType.getComponentType().isPrimitive() ? Primitives.unbox(item.getClass()) : item.getClass();
writer.startNode(itemName, itemType);
if (!itemType.equals(arrayType.getComponentType())) {
final String attributeName = mapper.aliasForSystemAttribute("class");
if (attributeName != null) {
writer.addAttribute(attributeName, mapper.serializedClass(itemType));
}
}
if (item != null) {
context.convertAnother(item);
}
writer.endNode();
}
}
@Override
public Object unmarshal(final HierarchicalStreamReader reader, final UnmarshallingContext context) {
final List<Object> list = new ArrayList<>();
while (reader.hasMoreChildren()) {
reader.moveDown();
final Object item;
final String className = HierarchicalStreams.readClassAttribute(reader, mapper);
final Class<?> itemType = className == null ? arrayType.getComponentType() : mapper.realClass(className);
if (Mapper.Null.class.equals(itemType)) {
item = null;
} else {
item = context.convertAnother(null, itemType);
}
list.add(item);
reader.moveUp();
}
final Object array = Array.newInstance(arrayType.getComponentType(), list.size());
for (int i = 0; i < list.size(); ++i) {
Array.set(array, i, list.get(i));
}
return array;
}
}