ps：看这篇博客之前首先要引入工具包json-lib-2.2.2-jdk15.jar

　　资源链接：百度云：链接：https://pan.baidu.com/s/1o9k7PSu 密码：00lj

 

一、从Object到String

　　要先用Object对象构造一个JSONObject或者JSONArray对象，然后调用它的toString()方法即可

　　（1）示例一

Book book=new Book();book.setName("Java");book.setPrice(52.3f);JSONObject object=JSONObject.fromObject(book);System.out.println(object.toString());

　　（2）示例二

Book book=new Book();book.setName("Java");book.setPrice(52.3f);        Book book2=new Book();book2.setName("C");book2.setPrice(42.3f);List list=new ArrayList();list.add(book);list.add(book2);JSONArray arry=JSONArray.fromObject(list);System.out.println(arry.toString());//结果如下：[{"name":"Java","price":52.3},{"name":"C","price":42.3}]

 

二、从String到Object

　　要先用String对象构造一个JSONObject或者JSONArray对象

　　（1）示例一

String json="{name:'Java',price:52.3}";    JSONObject object=JSONObject.fromObject(json);System.out.println(object.get("name")+" "+object.get("price"));

　　（2）示例二

String json="[{name:'Java',price:52.3},{name:'C',price:42.3}]";JSONArray array=JSONArray.fromObject(json);for(int i=0;i

 

三、从String到Bean

　　（1）单个Bean对象

String json="{name:'Java',price:52.3}";JSONObject object=JSONObject.fromObject(json);Product product=(Product)JSONObject.toBean(object,Product.class);System.out.println(product.getName()+" "+product.getPrice());

　　（2）Bean的数组

String json="[{name:'Java',price:52.3},{name:'C',price:42.3}]";JSONArray array=JSONArray.fromObject(json);Product[] products=(Product[]) JSONArray.toArray(array,Product.class);for(Product p:products){       System.out.println(p.getName()+" "+p.getPrice()); }

 

三、自定义封装JSON操作的类

package com.util;import java.util.List;import java.util.Map;import net.sf.json.JSONArray;import net.sf.json.JSONObject;public class JsonHelper {    //从普通的Bean转换为字符串    public static String getJson(Object o){        JSONObject jo=JSONObject.fromObject(o);        return jo.toString();    }    //从Java的列表转换为字符串    public static String getJson(List list){        JSONArray ja=JSONArray.fromObject(list);        return ja.toString();    }    //从Java对象数组转换为字符串    public static String getJson(Object[] arry){        JSONArray ja=JSONArray.fromObject(arry);        return ja.toString();    }    //从json格式的字符串转换为Map对象    public static Map getObject(String s){        return     JSONObject.fromObject(s);    }    //从json格式的字符串转换为List数组    public static List getArray(String s){        return JSONArray.fromObject(s);    }    //从json格式的字符串转换为某个Bean    public static Object getObject(String s,Class cls){        JSONObject jo=JSONObject.fromObject(s);        return JSONObject.toBean(jo, cls);    }    //从json格式的字符串转换为某类对象的数组    public static Object getArray(String s,Class cls){        JSONArray ja=JSONArray.fromObject(s);        return JSONArray.toArray(ja, cls);    }}