JSONObject和JSONArray使用

1.所依赖JAR包

要使程序可以运行必须引入JSON-lib包，JSON-lib包同时依赖于以下的JAR包：

commons-lang.jar

commons-beanutils.jar

commons-collections.jar

commons-logging.jar

ezmorph.jar

json-lib-2.2.2-jdk15.jar

2.Demo

2.1 应用场景:

后台的java类，如实体类、List、Set、Map转成json字符串发送到其它项目或者jsp端

jsp端或者其它项目发送过来的json字符串，需要解析成l实体类、List、Set、Map等java类

2.2 Student实体类

package json;

import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class Student {
private int id;
private String name;
private String age;
private Date birthDay;
private List list;
private Set set;
private Map map;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}

public Date getBirthDay() {
return birthDay;
}
public void setBirthDay(Date birthDay) {
this.birthDay = birthDay;
}

public List getList() {
return list;
}
public void setList(List list) {
this.list = list;
}
public Set getSet() {
return set;
}
public void setSet(Set set) {
this.set = set;
}

public Map getMap() {
return map;
}
public void setMap(Map map) {
this.map = map;
}
@Override
public String toString() {
return "Student [id=" + id + ", name=" + name + ", age=" + age
+ ", birthDay=" + birthDay + ", list=" + list + ", set=" + set
+ ", map=" + map + "]";
}

}

2.3 java对象序列化成json对象时，处理日期的处理类

package json;

import java.text.SimpleDateFormat;
import java.util.Date;

import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonValueProcessor;
/**
*
* @author yangguojun
* java实体类转jsonObject时,日期处理类
*/
public class JsonDateValueProcessor implements JsonValueProcessor {
/**
* 集合中实体类日期处理
*/
@Override
public Object processArrayValue(Object value , JsonConfig config) {
// TODO Auto-generated method stub
return processor(value);
}
/**
* 当个实体类日期处理
*/
@Override
public Object processObjectValue(String propertyName, Object value, JsonConfig config) {
return processor(value);
}
/**
* 把日期对象转为字符串
* @param value
* @return
*/
private Object processor(Object value){
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
if(value instanceof Date){
return format.format(value);
}
return value == null ? "":value.toString();
}

}

2.4 测试类

package json;

import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;

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

public class JsonDemo {
public static void main(String[] args) {
//创建JSON对象的第一种方法
JSONObject jsonObj1 = new JSONObject();
jsonObj1.put("id", "1");
jsonObj1.put("name", "rose");
jsonObj1.put("age", 25);
System.out.println("jsonObj1"+jsonObj1);
//创建JSON对象的第二种方法
HashMap<String, Object> map = new HashMap<String,Object>();
map.put("id", "2");
map.put("name", "zhangsan");
map.put("age", "25");
JSONObject jsonObj2 = JSONObject.fromObject(map);
System.out.println("jsonObj2"+jsonObj2);

//创建一个JsonArray方法1
JSONArray jsonArray = new JSONArray();
jsonArray.add(0, "ZHULI");
jsonArray.add(1, "30");
jsonArray.add(2, "ALI");
System.out.println("jsonArray1：" + jsonArray);

//创建JsonArray方法2
ArrayList<String> arrayList = new ArrayList<String>();
arrayList.add("柯文修");
arrayList.add("23");
arrayList.add("5");
System.out.println("jsonArray2：" + JSONArray.fromObject(arrayList));

//创建一个复杂JSON对象（JSON对象里有JSON数组）
JSONObject jsonObj3 = new JSONObject();
jsonObj3.put("id", 3);
jsonObj3.put("name", "lisi");
jsonObj3.put("age", 23);
jsonObj3.put("arrayList", arrayList);
System.out.println("jsonObj3"+jsonObj3);

//创建一个复杂JSON数组(JSON数组里含有JSON对象)、
JSONArray jsonArray3 = new JSONArray();
jsonArray3.add("4");
jsonArray3.add("wangwu");
jsonArray3.add("26");
jsonArray3.add(map);
System.out.println("jsonArray3"+jsonArray3);
//把JSON字符串转为JSON对象
String jsonString = "{\"id\":3,\"name\":\"lisi\",\"age\":23,\"arrayList\":[\"ZHULI\",\"30\",\"ALI\"]}";
JSONObject jsonObj4 = JSONObject.fromObject(jsonString);
System.out.println(jsonObj4.get("id")+"--"+jsonObj4.get("name")+"--"+jsonObj4.get("age")+
"--"+jsonObj4.get("arrayList"));
//java实体类转为JSONObject
Student stu = new Student();
stu.setId(1);
stu.setName("罗志茂");
stu.setAge("23");
stu.setBirthDay(new Date());
stu.setList(arrayList);
HashSet<Object> set = new HashSet<>();
set.add("6");
set.add("戚广辉");
set.add("25");
stu.setSet(set);
stu.setMap(map);
JsonConfig jsonConfig = new JsonConfig();
jsonConfig.registerJsonValueProcessor(Date.class, new JsonDateValueProcessor());
JSONObject jsonObj5 = JSONObject.fromObject(stu,jsonConfig);
System.out.println("序列化:"+jsonObj5);
//json转java实体类
Student student = (Student) JSONObject.toBean(jsonObj5, Student.class);
System.out.println("反序列化:"+student);
}

}

2.5 测试结果

jsonObj1{"id":"1","name":"rose","age":25}
jsonObj2{"id":"2","age":"25","name":"zhangsan"}
jsonArray1：["ZHULI","30","ALI"]
jsonArray2：["柯文修","23","5"]
jsonObj3{"id":3,"name":"lisi","age":23,"arrayList":["柯文修","23","5"]}
jsonArray3["4","wangwu","26",{"id":"2","age":"25","name":"zhangsan"}]
3--lisi--23--["ZHULI","30","ALI"]
序列化:{"age":"23","birthDay":"2016-08-13 23:22:27","id":1,"list":["柯文修","23","5"],"map":{"id":"2","age":"25","name":"zhangsan"},"name":"罗志茂","set": ["戚广辉","6","25"]}
反序列化:Student [id=1, name=罗志茂, age=23, birthDay=Sat Aug 13 23:22:27 CST 2016, list=[柯文修, 23, 5], set=[戚广辉, 6, 25], map={id=2, name=zhangsan, age=25}]