将java对象转成json字符串

如果要将数组、对象、Map、List转换成JSON数据,那我们需要一些jar包：

json-lib-2.4-jdk15.jar

ezmorph-1.0.6.jar

commons-logging.jar

commons-lang.jar

commons-collections.jar

commons-beanutils.jar

下面是与大家分享的代码：

 

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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


public class Test {
public static void main(String[] args) {
//将对象转成json 
Student student = new Student();
student.setAge(18);
student.setName("zhangsan");
student.setSex("male");
JSONObject jsonObject = JSONObject.fromObject(student);
System.out.println(jsonObject);

//控制台输出{"age":18,"name":"zhangsan","sex":"male"}

//将数组或list转成json 
Student[] stus = new Student[5];
List<Student> stuList = new ArrayList<Student>();
for (int i = 0; i < stus.length; i++) {
stus[i] = new Student();
stus[i].setAge(i*10+8);
stus[i].setName("zhang"+i);
stus[i].setSex("male");
//添加到list,一会儿用
stuList.add(stus[i]);
}
JSONArray jsonArray = JSONArray.fromObject(stus);
System.out.println(jsonArray);

//和下面打印的结果相同
// 结果：[{"age":8,"name":"zhang0","sex":"male"}, {"age":18,"name":"zhang1","sex":"male"},{"age":28,"name":"zhang2","sex":"male"},{"age":38,"name":"zhang3","sex":"male"},{"age":48,"name":"zhang4","sex":"male"}]
JSONArray jsonArrayFromList = JSONArray.fromObject(stuList);
System.out.println(jsonArrayFromList);

//和上面打印的结果相同
//当既有对象又有数组的时候
Map<String,Object> map = new HashMap<String,Object>();
Teacher teacher = new Teacher();
teacher.setAge(30);
teacher.setName("laoshi");
teacher.setSex("male");
map.put("teacher", teacher);
map.put("student", stuList);
JSONObject jsonObjectFromMap = JSONObject.fromObject(map);
System.out.println(jsonObjectFromMap);
//结果：
//{"student":[{"age":8,"name":"zhang0","sex":"male"},{"age":18,"name":"zhang1","sex":"male"},{"age":28,"name":"zhang2","sex":"male"},{"age":38,"name":"zhang3","sex":"male"},{"age":48,"name":"zhang4","sex":"male"}],"teacher":{"age":30,"name":"laoshi","sex":"male"}}
}
}