java json字符串操作

你的名字 2022-07-16 09:52 210阅读 0赞

以下导入jar包：

//json-lib-2.2-jdk15.jar

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

1、字符串转成一个json 数组

String strs="[{'valueCode':1,'valueName':'外请统调车'},{'valueCode':2,'valueName':'合同车'},{'valueCode':3,'valueName':'其他'},{'valueCode':1,'valueName':'精准整车'},{'valueCode':2,'valueName':'整车配送'},{'valueCode':3,'valueName':'精准专车'}]"
    net.sf.json.JSONArray  json = net.sf.json.JSONArray.fromObject(strs); 
    if(json.size()>0){
    	for(int i=0;i<json.size();i++){
    		net.sf.json.JSONObject job = json.getJSONObject(i);  // 遍历 jsonarray 数组，把每一个对象转成 json 对象
    		System.out.println(job.get("valueCode")+"=") ;  // 得到 每个对象中的属性值
    	}
    }

2、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();

3、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());

4、 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);

5、 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);