Java 简单 bean 与 json 互相转换

场景说明

最近在写一个服务，经常用到调别人接口得到json，然后需要转换为 指定bean,记录一下常用工具类

引入依赖

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
        </dependency>
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
        </dependency>

示例

bean 

@Data
public class User {
    private Integer id;
    private String name;
    private List<String> books;
}

转换

    @Test
    public void testjson() {
        User user = new User();
        user.setId(1001);
        user.setName("金庸");
        ArrayList<String> books = new ArrayList<>();
        books.add("飞");
        books.add("雪");
        books.add("连");
        books.add("天");
        books.add("射");
        books.add("白");
        books.add("🦌");
        user.setBooks(books);

        //使用  fastjson   bean2json
        String jsonStr = JSON.toJSONString(user);
        System.out.println(jsonStr);
        //使用  fastjson  json2bean
        User user1 = JSONObject.parseObject(jsonStr, User.class);
        System.out.println(user1);
        //使用  hutool   bean2json
        String jsonStr1 = JSONUtil.toJsonStr(user);
        System.out.println(JSONObject.parseObject(jsonStr1, User.class));
        //使用  hutool  json2bean
        System.out.println(JSONUtil.toBean(jsonStr1, User.class));
    }

执行效果：

{"books":["飞","雪","连","天","射","白","🦌"],"id":1001,"name":"金庸"}
User(id=1001, name=金庸, books=[飞, 雪, 连, 天, 射, 白, 🦌])
User(id=1001, name=金庸, books=[飞, 雪, 连, 天, 射, 白, 🦌])
User(id=1001, name=金庸, books=[飞, 雪, 连, 天, 射, 白, 🦌])

JSON数组

来一个 jsonarray

    @Test
    public void testjsonArray() {
        ArrayList<User> users = new ArrayList<>();
        User jiny = new User();
        jiny.setId(1001);
        jiny.setName("金庸");
        ArrayList<String> books = new ArrayList<>();
        books.add("飞");
        books.add("雪");
        books.add("连");
        books.add("天");
        books.add("射");
        books.add("白");
        books.add("🦌");
        jiny.setBooks(books);

        User gul = new User();
        gul.setId(1002);
        gul.setName("古龙");

        ArrayList<String> bookgl = new ArrayList<>();
        bookgl.add("绝");
        bookgl.add("萧");
        bookgl.add("流");
        bookgl.add("天");
        bookgl.add("武");
        bookgl.add("大");
        bookgl.add("小");
        gul.setBooks(bookgl);

        users.add(jiny);
        users.add(gul);
        //hu tool 工具包
        String jsonStr = JSONUtil.toJsonStr(users);
        System.out.println(jsonStr);
        List<User> list = JSONUtil.toList(jsonStr, User.class);
        System.out.println(users);
        System.out.println(list);
        System.out.println("--------------");
        //fastjson 工具包
        String jsonString = JSON.toJSONString(users);
        System.out.println(jsonString);
        JSONArray jsonArray = JSONArray.parseArray(jsonString);
        List<User> javaList = jsonArray.toJavaList(User.class);
        System.out.println(javaList);
    }

执行效果

[{"books":["飞","雪","连","天","射","白","🦌"],"name":"金庸","id":1001},{"books":["绝","萧","流","天","武","大","小"],"name":"古龙","id":1002}]
[User(id=1001, name=金庸, books=[飞, 雪, 连, 天, 射, 白, 🦌]), User(id=1002, name=古龙, books=[绝, 萧, 流, 天, 武, 大, 小])]
[User(id=1001, name=金庸, books=[飞, 雪, 连, 天, 射, 白, 🦌]), User(id=1002, name=古龙, books=[绝, 萧, 流, 天, 武, 大, 小])]
--------------
[{"books":["飞","雪","连","天","射","白","🦌"],"id":1001,"name":"金庸"},{"books":["绝","萧","流","天","武","大","小"],"id":1002,"name":"古龙"}]
[User(id=1001, name=金庸, books=["飞","雪","连","天","射","白","🦌"]), User(id=1002, name=古龙, books=["绝","萧","流","天","武","大","小"])]