json数据转java对象(复杂java对象)

package json;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

/**
* 要想实现JSON和java对象之间的互转，需要借助第三方jar包，这里使用json-lib这个jar包，
* json-lib需要commons-beanutils、commons-collections、commons-lang、
* commons-logging、ezmorph五个包的支持.
* json-lib提供了几个类可以完成此功能，例，JSONObject、JSONArray。
* 从类的名字上可以看出JSONObject转化的应该是对象格式的，而JSONArray转化的则应该是数组对象（即，带[]形式）的。
* @author hg
*
*/
@SuppressWarnings("rawtypes")
public class JsonHandle {

public static void main(String[] args) {
JsonHandle jsonHandle = new JsonHandle();
jsonHandle.JsonArrayDemo();
jsonHandle.JsonObjectDemo();
}

/**
* JSON 数组对象格式 [ 开始的json数据
*/
public void JsonArrayDemo(){

String jsonStr = "[{\"name\":\"小贺\",\"age\":20,\"sex\":\"男\","
+ "\"pictures\":[{\"fileName\":\"1.jpg\",\"pictureUrl\":\"http://www.1.jsp\"},"
+ "{\"fileName\":\"2.jpg\",\"pictureUrl\":\"http://www.2.jsp\"}]},"
+ "{\"name\":\"小露\",\"age\":19,\"sex\":\"女\","
+ "\"pictures\":[{\"fileName\":\"3.jpg\",\"pictureUrl\":\"http://www.3.jsp\"},"
+ "{\"fileName\":\"4.jpg\",\"pictureUrl\":\"http://www.4.jsp\"}]}]";

//数组对象格式使用JSONArray
JSONArray jsonArray = JSONArray.fromObject(jsonStr);

//对应json的数组 List<PersonalInfo>
List<PersonalInfo> personalInfos =new ArrayList<PersonalInfo>();

//遍历 jsonArray
for(int i=0;i<jsonArray.size();i++){

//获得jsonArray的第 i 个元素
Object o = jsonArray.get(i);

//转换为单个 JSONObject 对象
JSONObject jsonObject = JSONObject.fromObject(o);

/*
* 当其中属性有类似List, Map,ArrayList就不可以了。 会报错：MorphDynaBean cannot be
* cast to ******。
* 在JSONObject.toBean的时候如果转换的类中有集合，
* 可以先定义    Map<String, Class<E>> classMap = new HashMap<String, Class<E>>();
* 在classMap中put你要转换的类中的集合名，比如:classMap.put("pictures", Picture.class);
* 然后在toBean()的时候把参数加上，
* 例如：PersonalInfo personalInfo =
* (PersonalInfo)JSONObject.toBean(jsonObject, PersonalInfo.class,classMap);
*/
Map<String, Class> pictureMap = new HashMap<String, Class>();

pictureMap.put("pictures",Picture.class);

//转化为java对象
PersonalInfo personalInfo =
(PersonalInfo)JSONObject.toBean(jsonObject, PersonalInfo.class,pictureMap);

//添加对象至数组
personalInfos.add(personalInfo);
}

for(PersonalInfo pi : personalInfos){
//对象toString()打印:PersonalInfo {name=小贺, age=20, sex=男, pictures=
//[{fileName=1.jpg, pictureUrl=http://www.1.jsp},
//{fileName=2.jpg, pictureUrl=http://www.2.jsp}]}
System.out.println(pi.toString());
}
}

/**
* JSON的对象格式的字符串  { 开始的json数据
*/
public void JsonObjectDemo(){

String jsonStr = "{\"name\":\"小贺\",\"age\":20,\"sex\":\"男\","
+ "\"pictures\":[{\"fileName\":\"1.jpg\",\"pictureUrl\":\"http://www.1.jsp\"},"
+ "{\"fileName\":\"2.jpg\",\"pictureUrl\":\"http://www.2.jsp\"}]}";

//1、使用JSONObject
JSONObject jsonObject=JSONObject.fromObject(jsonStr);

Map<String, Class> pictureMap = new HashMap<String, Class>();

pictureMap.put("pictures",Picture.class);

//转化为java对象
PersonalInfo personalInfo =
(PersonalInfo)JSONObject.toBean(jsonObject, PersonalInfo.class,pictureMap);

//对象toString()打印:PersonalInfo {name=小贺, age=20, sex=男,
//pictures=[{fileName=1.jpg, pictureUrl=http://www.1.jsp},
//{fileName=2.jpg, pictureUrl=http://www.2.jsp}]}
System.out.println(personalInfo.toString());

}
}

package json;

import java.util.List;

/**
* 个人信息
* @author hg
*
*/
public class PersonalInfo {
private String name;            //姓名
private Integer age;            //年龄
private String sex;             //性别
private List<Picture> pictures; //照片

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public List<Picture> getPictures() {
return pictures;
}
public void setPictures(List<Picture> pictures) {
this.pictures = pictures;
}

public String toString() {
String picturesStr = "";
for(int i=0;i<pictures.size();i++){
picturesStr+=pictures.get(i).toString();
if(i<pictures.size()-1){
picturesStr+=",";
}
}
return "PersonalInfo {name=" + name + ", age="
+ age + ", sex=" + sex + ", pictures=[" + picturesStr+ "]}";
}
}

package json;

/**
* 个人照片Entity
* @author hg
*
*/
public class Picture {
private String fileName;    //文件名
private String pictureUrl;  //照片Url

public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
public String getPictureUrl() {
return pictureUrl;
}
public void setPictureUrl(String pictureUrl) {
this.pictureUrl = pictureUrl;
}

public String toString() {
return "{fileName=" + fileName + ", pictureUrl=" + pictureUrl + "}";
}
}

{
"name":"小贺",
"age":20,
"sex":"男",
"pictures":[
{
"fileName":"1.jpg",
"pictureUrl":"http://www.1.jsp"
},
{
"fileName":"2.jpg",
"pictureUrl":"http://www.2.jsp"
}
]
}

[
{
"name":"小贺",
"age":20,
"sex":"男",
"pictures":[
{
"fileName":"1.jpg",
"pictureUrl":"http://www.1.jsp"
},
{
"fileName":"2.jpg",
"pictureUrl":"http://www.2.jsp"
}
]
},
{
"name":"小露",
"age":19,
"sex":"女",
"pictures":[
{
"fileName":"3.jpg",
"pictureUrl":"http://www.3.jsp"
},
{
"fileName":"4.jpg",
"pictureUrl":"http://www.4.jsp"
}
]
}
]