JSONObject与JSONArray使用

JSONObject与JSONArray

Java不像PHP解析和生产JSON总是一个比较痛苦的过程。但是使用JSONObject和JSONArray会让整个过程相对舒服一些。

JsonObject和JsonArray区别就是JsonObject是对象形式，JsonArray是数组形式

需要依赖的包：

commons-lang.jar

commons-beanutils.jar

commons-collections.jar

commons-logging.jar

ezmorph.jar

json-lib-2.2.2-jdk15.jar

生成JSON：

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public class Test2 {
public static void main(String[] args) {
/* 创建JsonObject第一种方法 */
JSONObject jsonObject = new JSONObject();
jsonObject.put("UserName", "ZHULI");
jsonObject.put("age", "30");
jsonObject.put("workIn", "ALI");
System.out.println("jsonObject1：" + jsonObject);
/* 创建JsonObject第二种方法 */
HashMap<String, String> hashMap = new HashMap<String, String>();
hashMap.put("UserName", "ZHULI");
hashMap.put("age", "30");
hashMap.put("workIn", "ALI");
System.out.println("jsonObject2 FROM HASHMAP：" + JSONObject.fromObject(hashMap));
/* 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("ZHULI");
arrayList.add("30");
arrayList.add("ALI");
System.out.println("jsonArray2 FROM ArrayList：" + JSONArray.fromObject(arrayList));
/* 如果JSONArray解析一个HashMap，则会将整个对象的放进一个数组的值中 */
System.out.println("jsonArray FROM HASHMAP：" + JSONArray.fromObject(hashMap));
/* 组装一个复杂的JSONArray */
JSONObject jsonObject2 = new JSONObject();
jsonObject2.put("UserName", "ZHULI");
jsonObject2.put("age", "30");
jsonObject2.put("workIn", "ALI");
jsonObject2.element("Array", arrayList);
jsonObject2.element("Object", jsonObject);
System.out.println("jsonObject2：" + jsonObject2);
}
}

结果：

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jsonObject1：{"workIn":"ALI","age":"30","UserName":"ZHULI"}
jsonObject2 FROM HASHMAP：{"workIn":"ALI","age":"30","UserName":"ZHULI"}
jsonArray1：["ZHULI","30","ALI"]
jsonArray2 FROM ArrayList：["ZHULI","30","ALI"]
jsonArray FROM HASHMAP：[{"workIn":"ALI","age":"30","UserName":"ZHULI"}]
jsonObject2：{"workIn":"ALI","age":"30","Array":["ZHULI","30","ALI"],"UserName":"ZHULI","Object":{"workIn":"ALI","age":"30","UserName":"ZHULI"}

解析JSON：

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package com.xxx.video.resource.controller.web;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class Test {
public static void main(String[] args) {
String jsonString = "{\"UserName\":\"ZHULI\",\"age\":\"30\",\"workIn\":\"ALI\",\"Array\":[\"ZHULI\",\"30\",\"ALI\"]}";
/* 将Json字符串转为java对象 */
JSONObject obj = JSONObject.fromObject(jsonString);
/* 获取Object中的UserName */
if (obj.has("UserName")) {
System.out.println("UserName:" + obj.getString("UserName"));
}
/* 获取ArrayObject */
if (obj.has("Array")) {
JSONArray transitListArray = obj.getJSONArray("Array");
for (int i = 0; i < transitListArray.size(); i++) {
System.out.print("Array:" + transitListArray.getString(i) + " ");
}
}
}
}

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UserName:ZHULI
Array:ZHULI Array:30 Array:ALI

对象遍历

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if (!obj.isNull("sku")) {
HashMap<String, String> skuMap = new HashMap<String, String>();
JSONObject skuObject = obj.getJSONObject("sku");
Iterator<String> keys = skuObject.keys();
String key;
Object o;
while (keys.hasNext()) {
key = keys.next();
o = skuObject.get(key);
skuMap.put(key, String.valueOf(o));
}
}

gson使用

gson和其他现有Java json类库最大的不同时gson需要序列化得实体类不需要使用annotation来标识需要序列化得字段，同时gson又可以通过使用annotation来灵活配置需要序列化的字段。

生成JOSN

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public class Test2 {
public static void main(String[] args) {
Gson gson = new Gson();
HashMap<String, String> map = new HashMap<String, String>(); //实例化一个hashmap
map.put("username", "initphp"); //新增一个数据
map.put("password", "test");
map.put("age", "100");
String mapToJson = gson.toJson(map);
System.out.println(mapToJson);
}
}

结果：

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{"username":"initphp","age":"100","password":"test"}

第二种，有确定的数据结构：

有一个person的类了

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publicclass Person {
private String name;
privateint age;
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param name the name to set
*/
publicvoid setName(String name) {
this.name = name;
}
/**
* @return the age
*/
publicint getAge() {
return age;
}
/**
* @param age the age to set
*/
publicvoid setAge(int age) {
this.age = age;
}
@Override
public String toString()
{
return name +":"+age;
}
}

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public class Test2 {
public static void main(String[] args) {
Gson gson = new Gson();
List<Person> persons = new ArrayList<Person>();
for (int i = 0; i < 10; i++) {
Person p = new Person();
p.setName("name" + i);
p.setAge(i * 5);
persons.add(p);
}
String str = gson.toJson(persons);
}
}

结果：

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[{"name":"name0","age":0},{"name":"name1","age":5},{"name":"name2","age":10},{"name":"name3","age":15},{"name":"name4","age":20},{"name":"name5","age":25},{"name":"name6","age":30},{"name":"name7","age":35},{"name":"name8","age":40},{"name":"name9","age":45}]