//json-lib-2.2-jdk15.jar
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
1. //把java 对象列表转换为json对象数组，并转为字符串
JSONArray array = JSONArray.fromObject(userlist);
String jsonstr = array.toString();
2.//把java对象转换成json对象，并转化为字符串
JSONObject object = JSONObject.fromObject(invite);
Log4jInit.ysulogger.debug(object.toString());
3.//把JSON字符串转换为JAVA 对象数组
String personstr = getRequest().getParameter("persons");
JSONArray json = JSONArray.fromObject(personstr);
List<InvoidPerson> persons = (List<InvoidPerson>)JSONArray.toCollection(json, nvoidPerson.class);
4.//把JSON字符串转换为JAVA 对象
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":"贺明","passporttype":"K"}]}";
JSONObject jsonobject = JSONObject.fromObject(str);
PassportLendsEntity passportlends = null;
try {
//获取一个json数组
JSONArray array = jsonobject.getJSONArray("passports");
//将json数组 转换成 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);
}
}
//转换PassportLendsEntity 实体类
passportlends = (PassportLendsEntity)JSONObject.toBean(jsonobject, PassportLendsEntity.class);