java对象转JSON

使用json-lib进行Java和JSON之间的转换

1. json-lib是一个java类库，提供将Java对象，包括beans, maps, collections, java arrays and XML等转换成JSON，或者反向转换的功能。

2. json-lib 主页 ：http://json-lib.sourceforge.net/

3.执行环境

需要以下类库支持

• jakarta commons-lang 2.5
• jakarta commons-beanutils 1.8.0
• jakarta commons-collections 3.2.1
• jakarta commons-logging 1.1.1
• ezmorph 1.0.6

4.功能示例

这里通过JUnit-Case例子给出代码示例

packagecom.mai.json;

import staticorg.junit.Assert.assertEquals;

importjava.util.ArrayList;
importjava.util.Date;
importjava.util.HashMap;
importjava.util.Iterator;
importjava.util.List;
importjava.util.Map;
importnet.sf.ezmorph.Morpher;
importnet.sf.ezmorph.MorpherRegistry;
importnet.sf.ezmorph.bean.BeanMorpher;
importnet.sf.json.JSONArray;
importnet.sf.json.JSONObject;
importnet.sf.json.util.JSONUtils;

importorg.apache.commons.beanutils.PropertyUtils;
importorg.junit.Test;

public classJsonLibTest{

/*
*普通类型、List、Collection等都是用JSONArray解析
*
*Map、自定义类型是用JSONObject解析
*可以将Map理解成一个对象，里面的key/value对可以理解成对象的属性/属性值
*即{key1:value1,key2,value2......}
*
*1.JSONObject是一个name:values集合，通过它的get(key)方法取得的是key后对应的value部分(字符串)
*通过它的getJSONObject(key)可以取到一个JSONObject，-->转换成map,
*通过它的getJSONArray(key)可以取到一个JSONArray，
*
*
*/

// 一般数组转换成JSON
@Test
public voidtestArrayToJSON(){
boolean[]boolArray= new boolean[]{ true, false, true};
JSONArrayjsonArray=JSONArray.fromObject(boolArray);
System.out.println(jsonArray);
// prints[true,false,true]
}


// Collection对象转换成JSON
@Test
public voidtestListToJSON(){
Listlist= newArrayList();
list.add("first");
list.add("second");
JSONArrayjsonArray=JSONArray.fromObject(list);
System.out.println(jsonArray);
// prints["first","second"]
}


// 字符串json转换成json，根据情况是用JSONArray或JSONObject
@Test
public voidtestJsonStrToJSON(){
JSONArrayjsonArray=JSONArray.fromObject("['json','is','easy']");
System.out.println(jsonArray);
// prints["json","is","easy"]
}


// Map转换成json，是用jsonObject
@Test
public voidtestMapToJSON(){
Mapmap= newHashMap();
map.put("name","json");
map.put("bool",Boolean.TRUE);
map.put("int", newInteger(1));
map.put("arr", newString[]{"a","b"});
map.put("func","function(i){returnthis.arr[i];}");

JSONObjectjsonObject=JSONObject.fromObject(map);
System.out.println(jsonObject);
}

// 复合类型bean转成成json
@Test
public voidtestBeadToJSON(){
MyBeanbean= newMyBean();
bean.setId("001");
bean.setName("银行卡");
bean.setDate( newDate());

ListcardNum= newArrayList();
cardNum.add("农行");
cardNum.add("工行");
cardNum.add("建行");
cardNum.add( newPerson("test"));

bean.setCardNum(cardNum);

JSONObjectjsonObject=JSONObject.fromObject(bean);
System.out.println(jsonObject);

}

// 普通类型的json转换成对象
@Test
public voidtestJSONToObject() throwsException{
Stringjson="{name=\"json\",bool:true,int:1,double:2.2,func:function(a){returna;},array:[1,2]}";
JSONObjectjsonObject=JSONObject.fromObject(json);
System.out.println(jsonObject);
Objectbean=JSONObject.toBean(jsonObject);
assertEquals(jsonObject.get("name"),PropertyUtils.getProperty(bean,"name"));
assertEquals(jsonObject.get("bool"),PropertyUtils.getProperty(bean,"bool"));
assertEquals(jsonObject.get("int"),PropertyUtils.getProperty(bean,"int"));
assertEquals(jsonObject.get("double"),PropertyUtils.getProperty(bean,"double"));
assertEquals(jsonObject.get("func"),PropertyUtils.getProperty(bean,"func"));
System.out.println(PropertyUtils.getProperty(bean,"name"));
System.out.println(PropertyUtils.getProperty(bean,"bool"));
System.out.println(PropertyUtils.getProperty(bean,"int"));
System.out.println(PropertyUtils.getProperty(bean,"double"));
System.out.println(PropertyUtils.getProperty(bean,"func"));
System.out.println(PropertyUtils.getProperty(bean,"array"));

ListarrayList=(List)JSONArray.toCollection(jsonObject.getJSONArray("array"));
for(Objectobject:arrayList){
System.out.println(object);
}

}


// 将json解析成复合类型对象,包含List
@Test
public voidtestJSONToBeanHavaList(){
Stringjson="{list:[{name:'test1'},{name:'test2'}],map:[{test1:{name:'test1'}},{test2:{name:'test2'}}]}";
// Stringjson="{list:[{name:'test1'},{name:'test2'}]}";
MapclassMap= newHashMap();
classMap.put("list",Person. class);
MyBeanWithPersondiyBean=(MyBeanWithPerson)JSONObject.toBean(JSONObject.fromObject(json),MyBeanWithPerson. class,classMap);
System.out.println(diyBean);

Listlist=diyBean.getList();
for(Objecto:list){
if(o instanceofPerson){
Personp=(Person)o;
System.out.println(p.getName());
}
}
}


// 将json解析成复合类型对象,包含Map
@Test
public voidtestJSONToBeanHavaMap(){
// 把Map看成一个对象
Stringjson="{list:[{name:'test1'},{name:'test2'}],map:{test1:{name:'test1'},test2:{name:'test2'}}}";
MapclassMap= newHashMap();
classMap.put("list",Person. class);
classMap.put("map",Map. class);
// 使用暗示，直接将json解析为指定自定义对象，其中List完全解析,Map没有完全解析
MyBeanWithPersondiyBean=(MyBeanWithPerson)JSONObject.toBean(JSONObject.fromObject(json),MyBeanWithPerson. class,classMap);
System.out.println(diyBean);

System.out.println("dothelistrelease");
List<Person>list=diyBean.getList();
for(Persono:list){
Personp=(Person)o;
System.out.println(p.getName());
}

System.out.println("dothemaprelease");

// 先往注册器中注册变换器，需要用到ezmorph包中的类
MorpherRegistrymorpherRegistry=JSONUtils.getMorpherRegistry();
MorpherdynaMorpher= newBeanMorpher(Person. class,morpherRegistry);
morpherRegistry.registerMorpher(dynaMorpher);


Mapmap=diyBean.getMap();
/* 这里的map没进行类型暗示，故按默认的，里面存的为net.sf.ezmorph.bean.MorphDynaBean类型的对象 */
System.out.println(map);
List<Person>output= newArrayList();
for(Iteratori=map.values().iterator();i.hasNext();){
// 使用注册器对指定DynaBean进行对象变换
output.add((Person)morpherRegistry.morph(Person. class,i.next()));
}

for(Personp:output){
System.out.println(p.getName());
}

}



}

5.下面提供上面例子所需的资源，包括jar包和代码

/Files/mailingfeng/json-lib/json-lib用例所需jar包和java类.rar

复制代码