在spring中向消息转换器添加LocalDate映射器

Question

有人能帮我一下吗？

我需要将Java8LocalDate转换为JSON，反之亦然，在我的REST应用程序中，我将调用REST API的MVC应用程序。由于默认JacksonJAXbJSONProvider不解析LOcalDate，所以我编写了如下所示的自定义映射器，并在pom.xml中添加了依赖项

public class LocalDateObjectMapperContextResolver implements ContextResolver<ObjectMapper>{
private final ObjectMapper MAPPER;

public LocalDateObjectMapperContextResolver() {
    MAPPER = new ObjectMapper();
    MAPPER.registerModule(new JavaTimeModule());
    //MAPPER.findAndRegisterModules();
    MAPPER.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
}

@Override
public ObjectMapper getContext(Class<?> type) {
    return MAPPER;
}

}

这是在Java 8 LocalDate Jackson格式中提出的

我需要将它传递给spring.xml中的消息转换器。

<mvc:annotation-driven>
    <mvc:message-converters>
        <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"
              p:objectMapper-ref="objectMapper"/>
    </mvc:message-converters>
</mvc:annotation-driven>

<mvc:annotation-driven >
    <mvc:message-converters register-defaults="false">
        <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" >
             <!--  p:objectMapper-ref="objectMapper"/> -->
             <property name="objectMapper" ref="localDateMapper" />
        </bean>
    </mvc:message-converters>
</mvc:annotation-driven>

这显然是不正确的，因为我在需要映射器的地方传递了解析器。如何调用自定义类的getContext（）方法并在消息转换器中进行设置？现在，它在创建名为'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter#0'的bean时开始抛出异常：无法创建类型为[org.springframework.http.converter.json.mappingJacksonHttpMessageConverter]的内部bean'org.springframework.web.servlet.mvc.method.annotation.requestMappingHandlerAdapter#0'而设置键为[0]的bean属性“Message Converters”；嵌套异常是org.springframework.beans.factory.beanCreationException：创建ServletContext资源[/WEB-INF/spring.xml]中定义的名为'org.springframework.http.converter.json.mappingJacksonHttpMessageConverter#0'的bean时出错：bean初始化失败；嵌套异常是org.springframework.beans.conversionNotSupportedException：未能将类型“****Package***.LocalDateObjectMapperContextResolver”的属性值转换为属性“Object Mapper”所需的类型“org.codehaus.jackson.map.ObjectMapper”；嵌套异常是java.lang.IllegalStateException：无法将类型[****Package***.LocalDateObjectMapperContextResolver]的值转换为属性“Object Mapper”所需的类型[org.codehaus.jackson.map.ObjectMapper]：找不到匹配的编辑器或转换策略

Answer 1

您只需要自定义模块，而不需要映射器。然后相应地配置spring：

<bean id="objectMapper" class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean"
      p:simpleDateFormat="yyyy-MM-dd"
      p:modulesToInstall="your.module.JavaTimeModule"/>

<bean id="xmlMapper" parent="objectMapper" p:createXmlMapper="true"/>

<mvc:annotation-driven>
    <mvc:message-converters>
        <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
            <property name="objectMapper" ref="objectMapper"/>
        </bean>
        <bean class="org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter">
            <property name="objectMapper" ref="xmlMapper"/>
        </bean>
    </mvc:message-converters>
</mvc:annotation-driven>