使用 RestTemplate 时如何配置内部 Jackson 映射器? [英] How can we configure the internal Jackson mapper when using RestTemplate?

问题描述

我想更新 Spring RestTemplate 使用的 jackson 映射器的 SerializationConfig.Feature... 属性，不知道如何获取它或我可以/应该在哪里配置它.

I want to update the SerializationConfig.Feature... properties of the jackson mapper used by Spring RestTemplate, Any idea how I can get to it or where I can/should configure it.

推荐答案

默认的RestTemplate构造函数注册了一组HttpMessageConverters:

The default RestTemplate constructor registers a set of HttpMessageConverters:

this.messageConverters.add(new ByteArrayHttpMessageConverter());
this.messageConverters.add(new StringHttpMessageConverter());
this.messageConverters.add(new ResourceHttpMessageConverter());
this.messageConverters.add(new SourceHttpMessageConverter());
this.messageConverters.add(new XmlAwareFormHttpMessageConverter());
if (jaxb2Present) {
    this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
}
if (jacksonPresent) {
    this.messageConverters.add(new MappingJacksonHttpMessageConverter());
}
if (romePresent) {
    this.messageConverters.add(new AtomFeedHttpMessageConverter());
    this.messageConverters.add(new RssChannelHttpMessageConverter());
}

MappingJacksonHttpMessageConverter 依次直接创建ObjectMapper 实例.您可以找到此转换器并替换 ObjectMapper 或在它之前注册一个新转换器.这应该有效:

The MappingJacksonHttpMessageConverter in turns, creates ObjectMapper instance directly. You can either find this converter and replace ObjectMapper or register a new one before it. This should work:

@Bean
public RestOperations restOperations() {
    RestTemplate rest = new RestTemplate();
    //this is crucial!
    rest.getMessageConverters().add(0, mappingJacksonHttpMessageConverter());
    return rest;
}

@Bean
public MappingJacksonHttpMessageConverter mappingJacksonHttpMessageConverter() {
    MappingJacksonHttpMessageConverter converter = new MappingJacksonHttpMessageConverter();
    converter.setObjectMapper(myObjectMapper());
    return converter;
}

@Bean
public ObjectMapper myObjectMapper() {
    //your custom ObjectMapper here
}

在 XML 中是这样的:

In XML it is something along these lines:

<bean id="restOperations" class="org.springframework.web.client.RestTemplate">
    <property name="messageConverters">
        <util:list>
            <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.StringHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.ResourceHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.xml.SourceHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.xml.XmlAwareFormHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
                <property name="objectMapper" ref="customObjectMapper"/>
            </bean>
        </util:list>
    </property>
</bean>

<bean id="customObjectMapper" class="org.codehaus.jackson.map.ObjectMapper"/>

请注意，转换并不是真正的 1:1 - 我必须在 XML 中显式创建 messageConverters 列表，而使用 @Configuration 方法我可以简单地引用现有的修改它.但这应该有效.

Note that the transition isn't really 1:1 - I have to explicitly create messageConverters list in XML while with @Configuration approach I could reference existing one and simply modify it. But this should work.

这篇关于使用 RestTemplate 时如何配置内部 Jackson 映射器?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！