java对象与json对象间的相互转换

工程中所需的jar包,因为在网上不太好找，所以我将它放到我的网盘里了，如有需要随便下载。

点击下载

1.简单的解析json字符串

首先将json字符串转换为json对象，然后再解析json对象，过程如下。

JSONObject jsonObject = JSONObject.fromObject(jsonStr);

根据json中的键得到它的值

String name = jsonObject.getString("name");
int num = jsonObject.getInt("num");
String sex = jsonObject.getString("sex");
int age = jsonObject.getInt("age");

2.将json字符串转换为java对象

同样先将json字符串转换为json对象，再将json对象转换为java对象，如下所示。

JSONObject obj = new JSONObject().fromObject(jsonStr);//将json字符串转换为json对象

将json对象转换为java对象

Person jb = (Person)JSONObject.toBean(obj,Person.class);//将建json对象转换为Person对象

3.将java对象转换为json字符串

先将java对象转换为json对象，在将json对象转换为json字符串

JSONObject json = JSONObject.fromObject(obj);//将java对象转换为json对象

String str = json.toString();//将json对象转换为字符串

完整代码如下：

[java] view plain copy

package baz.parse;
import java.util.ArrayList;
import java.util.List;
import net.sf.json.JSON;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;
import baz.bean.Person;
public class ParseJson {
private String jsonStr;
public ParseJson() {
}
public ParseJson(String str){
this.jsonStr = str;
}
/**
* 解析json字符串
*/
public void parse(){
JSONObject jsonObject = JSONObject.fromObject(jsonStr);
String name = jsonObject.getString("name");
int num = jsonObject.getInt("num");
String sex = jsonObject.getString("sex");
int age = jsonObject.getInt("age");
System.out.println(name + " " + num + " " + sex + " " + age);
}
//将json字符串转换为java对象
public Person JSON2Object(){
//接收{}对象，此处接收数组对象会有异常
if(jsonStr.indexOf("[") != -1){
jsonStr = jsonStr.replace("[", "");
}
if(jsonStr.indexOf("]") != -1){
jsonStr = jsonStr.replace("]", "");
}
JSONObject obj = new JSONObject().fromObject(jsonStr);//将json字符串转换为json对象
Person jb = (Person)JSONObject.toBean(obj,Person.class);//将建json对象转换为Person对象
return jb;//返回一个Person对象
}
}

[java] view plain copy

package baz.bean;
public class Person {
private String name;
private int num;
private String sex;
private int age;
public Person() {
// TODO Auto-generated constructor stub
}
public Person(String name, int num, String sex, int age) {
super();
this.name = name;
this.num = num;
this.sex = sex;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getNum() {
return num;
}
public void setNum(int num) {
this.num = num;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}

将java对象转换为json字符串

[java] view plain copy

package baz.cons;
import net.sf.json.JSONObject;
/**
* 将java对象转换为json字符串
* @author Administrator
*
*/
public class ConsJson {
public ConsJson() {
// TODO Auto-generated constructor stub
}
public String Object2Json(Object obj){
JSONObject json = JSONObject.fromObject(obj);//将java对象转换为json对象
String str = json.toString();//将json对象转换为字符串
return str;
}
}

测试类：

[java] view plain copy

package baz.test;
import java.util.List;
import baz.bean.Person;
import baz.cons.ConsJson;
import baz.parse.ParseJson;
public class Test {
public static void main(String[] args) {
//将字符串转换为json对象，然后根据建得到相应的值
ParseJson pj = new ParseJson("{\"name\":\"gu\",\"num\":123456,\"sex\":\"male\",\"age\":24}");
pj.parse();
//将一个json字符串转换为java对象
Person p = pj.JSON2Object();
System.out.println("Name:" + p.getName());
System.out.println("Num:" + p.getNum());
System.out.println("Sex:" + p.getSex());
System.out.println("age:" + p.getAge());
//将一个java对象转换为Json字符串
Person p1 = new Person("gu1",123,"male",23);
ConsJson cj = new ConsJson();
String str1 = cj.Object2Json(p1);
System.out.println(str1);
}
}

测试输出如下：
gu 123456 male 24
Name:gu
Num:123456
Sex:male
age:24
{"age":23,"name":"gu1","num":123,"sex":"male"}

转载于:https://my.oschina.net/u/1780920/blog/500081