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。

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
}
}

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"}

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); } }

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; } }

[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; } }