JSON与Javabean转换的几种形式

JSON格式的数据传递是最常用的方法之一，以下列出了常用的几种形态以及与Javabean之间的转换：

　　String json1="{'name':'zhangsan','age':23,'interests':[{'interest':'篮球','colors':['绿色','黄色']},{'interest':'足球','colors':['红色','蓝色']}]}";
　　String json2="[{'name':'zhangsan'},{'name':'lisi'},{'name':'王五'}]";
　　String json3="{'1':{'name':'zhangsan'},'3':{'name':'lisi'},'4':{'name':'wangwu'}}";//map
　　String json4="{'name':'zhangsan','age':23}";

首先，此处的转化依赖两个JAR包

     <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
     <dependency>
         <groupId>com.google.code.gson</groupId>
         <artifactId>gson</artifactId>
         <version>2.8.1</version>
     </dependency>
     <!-- https://mvnrepository.com/artifact/org.json/json -->
     <dependency>
         <groupId>org.json</groupId>
         <artifactId>json</artifactId>
         <version>20170516</version>
     </dependency>

其次，封装的Javabean代码如下

 import java.util.List;

 public class UserBean {

     private String name;

     private Integer age;

     private List<InterestBean> interests;

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public Integer getAge() {
         return age;
     }

     public void setAge(Integer age) {
         this.age = age;
     }

     public List<InterestBean> getInterests() {
         return interests;
     }

     public void setInterests(List<InterestBean> interests) {
         this.interests = interests;
     }

      class InterestBean{
         private String interest;

         private List<String> colors;

         public String getInterest() {
             return interest;
         }

         public void setInterest(String interest) {
             this.interest = interest;
         }

         public List<String> getColors() {
             return colors;
         }

         public void setColors(List<String> colors) {
             this.colors = colors;
         }

     }

 }

1、普通的json4格式的JSON解析：

 public void testParseJson(){

         JSONObject jsonObj = new JSONObject(json4);
         String name = jsonObj.getString("name");
         int age = jsonObj.getInt("age");
         System.out.println(name);
         System.out.println(age);
         UserBean user = new UserBean();
         user.setAge(age);
         user.setName(name);

     }

2、数组形式的JSON解析以及GSON解析：

 public void testJsonArray(){
         JSONArray jsonArray = new JSONArray(json2);
         for (int i = 0; i < jsonArray.length(); i++) {
             JSONObject jsonObj = jsonArray.getJSONObject(i);
             String name = jsonObj.getString("name");
             System.out.println(name);

         }
     }

     /**
      * 解析json数组
      */
     public void testParseListJson(){
         Gson gson = new Gson();
         Type type = new TypeToken<List<UserBean>>(){}.getType();
         List<UserBean> users = gson.fromJson(json2, type);
         for(UserBean user:users){
             System.out.println(user.getName());
         }
     }

3、内嵌JSON形式的JSON与GSON解析：

 /**
      * 内嵌JSON解析
      */
     public void testParseJson1(){
         JSONObject rootJson = new JSONObject(json1);
         JSONArray jsonInterestArray = rootJson.getJSONArray("interests");
         for (int i = 0; i < jsonInterestArray.length(); i++) {
             JSONObject interestJsonObj = jsonInterestArray.getJSONObject(i);
             String interest = interestJsonObj.getString("interest");
             System.out.println(interest);
             Object obj = interestJsonObj.get("colors");
             System.out.println(obj);
         }
     }

 /**
      * 内嵌GSON解析
      */
     public void testSimpleJson(){
         Gson gson = new Gson();
         UserBean user = gson.fromJson(json1, UserBean.class);
         System.out.println(user.getName());
         System.out.println(user.getAge());
         System.out.println(user.getInterests().size());
         List<InterestBean> list = user.getInterests();
         for(InterestBean bean:list) {
             System.out.println(bean.getInterest());
             List<String> colors = bean.getColors();
             for(String color:colors){
                 System.out.println(color);
             }
         }
     }

4、Map形式的JSON的GSON解析：

     /**
      * 解析一个map类型的json
      */
     public void testParseMapJson(){
         Gson gson = new Gson();
         Type type = new TypeToken<Map<String,UserBean>>(){}.getType();
         Map<String,UserBean> map = gson.fromJson(json3, type);
         Set<String> keys = map.keySet();
         for(String key:keys){
             UserBean bean = map.get(key);
             System.out.println(key);
             System.out.println(bean.getName());
         }
     }

5、将一个JavaBean对象封装成JSON格式

     /**
      * 将一个JavaBean对象封装成JSON格式
      */
     public String testJavaBean2Json(){
         UserBean userBean = new UserBean();
         userBean.setName("zhangsan");
         userBean.setAge(33);
         List<InterestBean> list = new ArrayList<InterestBean>();
         InterestBean bean1 = new UserBean().new InterestBean();
         bean1.setInterest("篮球1");
         InterestBean bean2 = new UserBean().new InterestBean();
         bean2.setInterest("篮球2");
         list.add(bean1);
         list.add(bean2);
         userBean.setInterests(list);
         //将User Bean转换成Json
         Gson gson = new Gson();
         String jsonStr = gson.toJson(userBean);
         System.out.println(jsonStr);
         return jsonStr;
     }

 }

仅供参考，如有雷同，纯属巧合^_^