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^_^