Java中的List转换成JSON报错（四）

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1、错误描述

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/collections/map/ListOrderedMapat net.sf.json.JSONObject.<init>(JSONObject.java:1450)at net.sf.json.util.CycleDetectionStrategy.<clinit>(CycleDetectionStrategy.java:37)at net.sf.json.JsonConfig.<clinit>(JsonConfig.java:65)at net.sf.json.JSONArray.fromObject(JSONArray.java:105)at com.you.model.ListToJSON.main(ListToJSON.java:29)Caused by: java.lang.ClassNotFoundException: org.apache.commons.collections.map.ListOrderedMapat java.net.URLClassLoader$1.run(URLClassLoader.java:366)at java.net.URLClassLoader$1.run(URLClassLoader.java:355)at java.security.AccessController.doPrivileged(Native Method)at java.net.URLClassLoader.findClass(URLClassLoader.java:354)at java.lang.ClassLoader.loadClass(ClassLoader.java:425)at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)at java.lang.ClassLoader.loadClass(ClassLoader.java:358)... 5 more

2、错误原因

/** * 将List转换成JSON */package com.you.model;import java.util.ArrayList;import java.util.List;import net.sf.json.JSONArray;/** * @author YouHaiDong * */public class ListToJSON {/** * @param args */public static void main(String[] args) {List<String> list = new ArrayList<String>();list.add("春天");list.add("夏天");list.add("秋天");list.add("冬天");JSONArray jsonArray = JSONArray.fromObject(list);System.out.println("List转换成JSON：" + jsonArray.toString());}}

从“Caused by: java.lang.ClassNotFoundException: org.apache.commons.collections.map.ListOrderedMap”可以看出，缺少jar

3、解决办法

将“commons-collections-3.1.jar”复制到lib目录下

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