Java XML与Map互转

将XML的实例对象转为JSON格式：

1. 导入XStream依赖:

<dependency>
    <groupId>xstream</groupId>
    <artifactId>xstream</artifactId>
    <version>1.2.2</version>
</dependency>

2. 测试代码如下：

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.converters.Converter;
import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;

import java.util.AbstractMap;
import java.util.HashMap;
import java.util.Map;

public class Test {

    public static void main(String[] args) {

        // 1. 定义一个map
        Map<String,String> map = new HashMap<String,String>();
        map.put("name","chris");
        map.put("island","faranga");

        // 2. 生成xml根标签
        XStream xStream = new XStream();
        xStream.registerConverter(new MapEntryConverter());
        xStream.alias("root", Map.class);

        // 3. 将map转换成xml格式
        String xml = xStream.toXML(map);
        System.out.println(xml);

        // 4. 解析xml字符串并转换为Map
        Map<String, String> extractedMap = (Map<String, String>) xStream.fromXML(xml);
        assert extractedMap.get("name").equals("chris");
        assert extractedMap.get("island").equals("faranga");

    }

    public static class MapEntryConverter implements Converter {

        public boolean canConvert(Class clazz) {
            return AbstractMap.class.isAssignableFrom(clazz);
        }

        public void marshal(Object value, HierarchicalStreamWriter writer, MarshallingContext context) {

            AbstractMap map = (AbstractMap) value;
            for (Object obj : map.entrySet()) {
                Map.Entry entry = (Map.Entry) obj;
                writer.startNode(entry.getKey().toString());
                Object val = entry.getValue();
                if ( null != val ) {
                    writer.setValue(val.toString());
                }
                writer.endNode();
            }

        }

        public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) {

            Map<String, String> map = new HashMap<String, String>();

            while(reader.hasMoreChildren()) {
                reader.moveDown();

                String key = reader.getNodeName(); // nodeName aka element's name
                String value = reader.getValue();
                map.put(key, value);

                reader.moveUp();
            }

            return map;
        }

    }
}

内容参考：https://stackoverflow.com/questions/1537207/how-to-convert-xml-to-java-util-map-and-vice-versa