// 引入相應的包

//json-lib-2.2-jdk15.jar

import net.sf.json.JSONArray;import net.sf.json.JSONObject;

1. //把java 對象列表轉換為json對象數組，并轉為字符串

    JSONArray array = JSONArray.fromObject(userlist);    String jsonstr = array.toString();

2.//把java對象轉換成json對象，并轉化為字符串

  JSONObject object = JSONObject.fromObject(invite);  Log4jInit.ysulogger.debug(object.toString());

3.//把JSON字符串轉換為JAVA 對象數組

  String personstr = getRequest().getParameter("persons");  JSONArray json = JSONArray.fromObject(personstr);  List<InvoidPerson> persons = (List<InvoidPerson>)JSONArray.toCollection(json, nvoidPerson.class);4.//把JSON字符串轉換為JAVA 對象

  str = "{/"lendperson/":/"李四/",/"lendcompany/":/"有限公司/",/"checkperson/":/"李四/",  /"lenddate/":/"2010-07-19T00:00:00/",/"lendcounts/":4,/"  passports/":[{/"passportid/":/"d/",/"name/":/"李豫川/",/"passporttype/":/"K/"},  {/"passportid/":/"K9051/",/"name/":/"李平/",/"passporttype/":/"K/"},  {/"passportid/":/"K90517/",/"name/":/"袁寒梅/",/"passporttype/":/"K/"},  {/"passportid/":/"K905199/",/"name/":/"賀明/",/"passporttype/":/"K/"}]}";   JSONObject jsonobject = JSONObject.fromObject(str);  PassportLendsEntity passportlends = null;  try {   //獲取一個json數組   JSONArray array = jsonobject.getJSONArray("passports");   //將json數組 轉換成 List<PassPortForLendsEntity>泛型   List<PassPortForLendsEntity> list = new ArrayList<PassPortForLendsEntity>();   for (int i = 0; i < array.size(); i++) {               JSONObject object = (JSONObject)array.get(i);              PassPortForLendsEntity passport = (PassPortForLendsEntity)JSONObject.toBean(object,              PassPortForLendsEntity.class);            if(passport != null){             list.add(passport);            }           }   //轉換PassportLendsEntity 實體類   passportlends = (PassportLendsEntity)JSONObject.toBean(jsonobject, PassportLendsEntity.class);