【业务功能篇50】ObjectMapper-将java对象转为json字符串

蔚落 2024-03-22 20:31 68阅读 0赞

> ObjectMapper可以实现Java对象和json字符串间互相转换，我们经常用到的是它的J**ava对象转json字符串功能**。 这里目的是

### Java对象 json字符串相互转换 api ###

*  【json字符串转为Java对象：readValue(json字符串,类.class)】
 *  【Java对象转为json字符串：writeValueAsString(class类对象)】

package test;
    import java.io.IOException;
    import java.util.*;
    import org.codehaus.jackson.JsonGenerationException;
    import org.codehaus.jackson.map.JsonMappingException;
    import org.codehaus.jackson.map.ObjectMapper;
    public class UserData {
        public static void main(String[] args) throws JsonGenerationException, JsonMappingException, IOException{
            ObjectMapper objectMapper = new ObjectMapper();
            User u = new User();
            u.setName("Lucy");
            u.setAge(10);
            u.setSex("woman");
            //对象转为json字符串
            String userJson = objectMapper.writeValueAsString(u);
            System.out.println("对象转为json字符串:");
            System.out.println(userJson);
            //json字符串转为对象
            String UserString = "{\"name\":\"Lily\", \"age\":9, \"sex\":\"woman\"}";
            User u2 = objectMapper.readValue(UserString,User.class);
            System.out.println("json字符串转为对象:");
            System.out.println(u2);
        }
    }

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[427ef4b70bbc44f7bb0f9dcbd7f2d4e7.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/14/c45d6cae5ba74bd986987392894ef430.png