Jackson序列化解决多态

╰半橙微兮° 2024-03-23 00:26 54阅读 0赞

在需要多态属性上使用jackson注解，注意不需要修改注解的参数。

@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS,include = JsonTypeInfo.As.PROPERTY,property = "@Clazz")

原理就是将class全名，写入到json str中，待反序列化时候利用 字符串的class名称。

举个例子：  
定义类：

@Data
    @NoArgsConstructor
    public class Canvas {
        
        @JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@clazz")
        private shape shape;
    
    
        @Data
        @NoArgsConstructor
        @AllArgsConstructor
        public static class shape {
        
            protected String name;
        }
    
        @Data
        @NoArgsConstructor
        public static class circle extends shape {
        
            private int radius;
            public circle(String name,int radius){
        
                super(name);
                this.radius = radius;
            }
        }
    }

测试

public class JacksonTest {
        
    
        @Test
        public void test01() throws JsonProcessingException {
        
            Canvas canvas1 = new Canvas();
            canvas1.setShape(new Canvas.shape("circle"));
            Canvas canvas2 = new Canvas();
            canvas2.setShape(new Canvas.circle("circle", 10));
            ObjectMapper objectMapper = new ObjectMapper();
            String c1Str = objectMapper.writeValueAsString(canvas1);
            System.out.println(c1Str);
            String c2Str = objectMapper.writeValueAsString(canvas2);
            System.out.println(c2Str);
    
            Canvas canvas1Clone = objectMapper.readValue(c1Str, Canvas.class);
            System.out.println(canvas1Clone);
            Canvas canvas2Clone = objectMapper.readValue(c2Str, Canvas.class);
            System.out.println(canvas2Clone);
        }
    }

结果：  
![在这里插入图片描述][d08981d5feea4101ad8ed090a2f3ba79.png]

[参考文章1][1]

[d08981d5feea4101ad8ed090a2f3ba79.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/14/4474f4d93b354f20bbfd8dab8508e1d1.png
[1]: https://www.dandelioncloud.cn/article/details/1523285106156666882