日期:2014-05-17  浏览次数:21090 次

java.lang.ClassNotFoundException: net.sf.json.JSONObject
昨天学习json,遇到一个很奇怪的问题:
  1.我已经在工程的lib目录下添加了json-lib-2.1-jdk15.jar
  2.同一工程下的PeopleBean.java类可以正确运行:
Java code


import java.util.HashMap;
import java.util.Map;

import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;
import net.sf.json.xml.XMLSerializer;

public class PeopleBean {

    private String name;
    
    private int age;
    
    private boolean gendar;
    
    //setter/getter
    public PeopleBean() {
    }

    public PeopleBean(String name, int age, boolean gendar) {
        this.name = name;
        this.age = age;
        this.gendar = gendar;
    }


    public static void main(String[] args) throws Exception{

        /**
         * 创建JSONObject对象
         */
        //Create a JSONObject from scratch
        JSONObject object1=new JSONObject();
        object1.element("name", "张三");
        object1.element("age", 24);
        object1.element("gendar", true);
    
        
        //Create a JSONObject from formatted String
        String jsonString1="{name:\"李四\",age:25,gendar:false}";
        JSONObject object2=JSONObject.fromObject(jsonString1);
        
        
        String jsonString2="{'name':'王五','age':22,'gendar':true}";
        JSONObject object3=(JSONObject)JSONSerializer.toJSON(jsonString2);
        
        //Create a JSONObject from a Map
        Map map=new HashMap();
        map.put("name", "刘六");
        map.put("age", 23);
        map.put("gendar", true);
        JSONObject object4=(JSONObject)JSONSerializer.toJSON(map);
        
        //Create a JSONObject from a bean
        PeopleBean WangNan=new PeopleBean("王l",26,true);
        JSONObject object5=(JSONObject)JSONSerializer.toJSON(WangNan);
        
        /**
         * 把JSONObject对象转化为Bean或Object
         */
        PeopleBean people=(PeopleBean)object5.toBean(object5, PeopleBean.class);
        System.out.println("name===="+people.getName()+" age======"+people.getAge()+"  gendar======"+people.isGendar());
    
        /**
         * From JSON to XML
         */
        
        JSONObject object6=new JSONObject(true);
        XMLSerializer xmlSerializer=new XMLSerializer();
        String xml1=xmlSerializer.write(object6);
        System.out.println(xml1);
        
        xmlSerializer.setRootName("people");
        xmlSerializer.setTypeHintsEnabled(false);
        String xml2=xmlSerializer.write(object5);
        System.out.println(xml2);
    
        /**
         * From XML to JSON
         */
        JSONObject object7=(JSONObject)xmlSerializer.read(xml2);
        System.out.println(object7);
    }

}



  3.同一工程下的UserController.java在tomcat启动后,报错java.lang.ClassNotFoundException: net.sf.json.JSONObject:
Java code

import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.multiaction1b0004:0:3;402881c42d8

请问是什么原因?

------解决方案--------------------
.jar包冲突了吧