package com.testjson;

public class Person
{
    private String name;
    
    private Integer age;
    
    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;
    }
    
}

?

package com.testjson;

import net.sf.json.JSONObject;

public class test
{
    public static void main(String[] args)
    {
        Person p = new Person();
        p.setAge(11);
        p.setName("测试");
        
        JSONObject jsonObj1 = JSONObject.fromObject(p);
        
        System.out.println("JSON输出后的：" + jsonObj1.toString());
        
        JSONObject jsonObj2 = JSONObject.fromObject(jsonObj1);
        
        System.out.println("JSONObject输出后的：" + jsonObj2.toString());
        
        Person p2 = (Person)JSONObject.toBean(jsonObj1, Person.class);
        
        System.out.println("json转化为对象：姓名：" + p2.getName() + ";年龄:" + p2.getAge());
        
        /*********处理js格式问题************/
        //        JsonConfig config = new JsonConfig();
        //        config.setIgnoreDefaultExcludes(false);
        //        config.registerJsonBeanProcessor(Date.class, new JsDateJsonBeanProcessor());
        /**************处理Integer为null时输出为0的问题 版本需要2.3**************/
        //        JsonConfig jsonConfig = new JsonConfig();
        //        jsonConfig.registerDefaultValueProcessor(Integer.class, new MyDefaultIntegerValueProcessor());
        //        JsonConfig jsonConfig = new JsonConfig();
        //        jsonConfig.findJsonValueProcessor(Integer.class, new DefaultValueProcessor()
        //        {
        //            public Object getDefaultValue(Class type)
        //            {
        //                return null;
        //            }
        //        });
        
    }
}

?

package com.testjson;

import net.sf.json.JSONNull;
import net.sf.json.processors.DefaultValueProcessor;

public class MyDefaultIntegerValueProcessor implements DefaultValueProcessor
{
    
    public Object getDefaultValue(Class type)
    {
        if (type != null && Integer.class.isAssignableFrom(type))
        {
            return Integer.valueOf(9999);
        }
        return JSONNull.getInstance();
    }
    
}

?