解决 No serializer 异常

柔情只为你懂 2022-04-06 16:26 427阅读 0赞

出现错误：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3N1cHJlemhlbmc_size_16_color_FFFFFF_t_70]解决办法;  
No serialzer 异常错误解决：  
一、【解决办法一】：在多对一的字段上加注解 **@JsonIgnoreProperties(value=\{“hibernateLazyInitializer”,“handler”,“fieldHandler”\})**

例：

@ManyToOne(fetch = FetchType.LAZY)
        @JoinColumn(name = "department_id")
        @JsonIgnoreProperties(value={"hibernateLazyInitializer","handler","fieldHandler"})
    private Department department;

二、【解决办法二】：【推荐使用】  
①：新建一个CustomMapper重写ObjectMapper

新建一个CustomMapper重写ObjectMapper
    public class CustomMapper extends ObjectMapper {
        public CustomMapper() {
            this.setSerializationInclusion(JsonInclude.Include.NON_NULL);
            // 设置 SerializationFeature.FAIL_ON_EMPTY_BEANS 为 false
            this.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
        }
    }

②：在springMVC.xml中配置

<mvc:annotation-driven>
            <mvc:message-converters>
                <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                    <property name="supportedMediaTypes">
                        <list>
                            <value>application/json; charset=UTF-8</value>
                            <value>application/x-www-form-urlencoded; charset=UTF-8</value>
                        </list>
                    </property>
                    
                    <property name="objectMapper">
                        <bean class="cn.mesmile.common.CustomMapper"></bean>
                    </property>
                </bean>
            </mvc:message-converters>
        </mvc:annotation-driven>

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