JAVA对象JSON数据互相转换的四种常见情况

这篇文章主要介绍了JAVA对象JSON数据互相转换的四种常见情况,需要的朋友可以参考下

1. 把java 对象列表转换为json对象数组，并转为字符串

代码如下:

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

代码如下:

JSONObject object = JSONObject.fromObject(invite);
String str=object.toString());

3.把JSON字符串转换为JAVA 对象数组

代码如下:

String personstr = getRequest().getParameter("persons");
JSONArray json = JSONArray.fromObject(personstr);
List persons = (List)JSONArray.toCollection(json, nvoidPerson.class);

4.把JSON字符串转换为JAVA 对象

代码如下:

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泛型
List list = new ArrayList();
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);
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\"}]}";