json与map之间的互相转换

@Test
public void test03(){
Map<String,Object> map = new HashMap<String,Object>();
map.put("method","json");
map.put("param",null);
map.put("time","2015-01-23 10:54:55");
JSONObject job = JSONObject.fromObject(map);
System.out.println("Job"+job);
System.out.println("Map"+map);
}

打印出来的结果

Job{"method":"json","param":null,"time":"2015-01-23 10:54:55"}
Map{method=json, param=null, time=2015-01-23 10:54:55}

JSONObject job = JSONObject.fromObject(map)

这一段代码是将map（Map类）转成job（JSONObject类的对象）；job是一段json类型的字符串，而map是Map类型的对象。

json----------->map

String str = "{\"0\":\"zhangsan\",\"1\":\"lisi\",\"2\":\"wangwu\",\"3\":\"maliu\"}";
Map mapTypes = com.alibaba.fastjson.JSON.parseObject(str);
System.out.println("这个是用JSON类的parseObject来解析JSON字符串!!!");
System.out.println(mapTypes.getClass());
Map<Integer,String> mmap = new HashMap<Integer,String>();
for (Object obj : mapTypes.keySet()){
mmap.put(Integer.parseInt((String)obj), (String) mapTypes.get(obj));
}
System.out.println(mmap.getClass().getName()+mmap);打印结果
这个是用JSON类的parseObject来解析JSON字符串!!!
class com.alibaba.fastjson.JSONObject
java.util.HashMap{0=zhangsan, 1=lisi, 2=wangwu, 3=maliu}