RestTemplate的converters配置

RestTemplate

org/springframework/spring-web/4.3.5.RELEASE/spring-web-4.3.5.RELEASE-sources.jar!/org/springframework/web/client/RestTemplate.java

    private final List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();

    /**
     * Create a new instance of the {@link RestTemplate} using default settings.
     * Default {@link HttpMessageConverter}s are initialized.
     */
    public RestTemplate() {
        this.messageConverters.add(new ByteArrayHttpMessageConverter());
        this.messageConverters.add(new StringHttpMessageConverter());
        this.messageConverters.add(new ResourceHttpMessageConverter());
        this.messageConverters.add(new SourceHttpMessageConverter<Source>());
        this.messageConverters.add(new AllEncompassingFormHttpMessageConverter());

        if (romePresent) {
            this.messageConverters.add(new AtomFeedHttpMessageConverter());
            this.messageConverters.add(new RssChannelHttpMessageConverter());
        }

        if (jackson2XmlPresent) {
            this.messageConverters.add(new MappingJackson2XmlHttpMessageConverter());
        }
        else if (jaxb2Present) {
            this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
        }

        if (jackson2Present) {
            this.messageConverters.add(new MappingJackson2HttpMessageConverter());
        }
        else if (gsonPresent) {
            this.messageConverters.add(new GsonHttpMessageConverter());
        }
    }

判断是否present

    private static boolean romePresent =
            ClassUtils.isPresent("com.rometools.rome.feed.WireFeed", RestTemplate.class.getClassLoader());

    private static final boolean jaxb2Present =
            ClassUtils.isPresent("javax.xml.bind.Binder", RestTemplate.class.getClassLoader());

    private static final boolean jackson2Present =
            ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", RestTemplate.class.getClassLoader()) &&
                    ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", RestTemplate.class.getClassLoader());

    private static final boolean jackson2XmlPresent =
            ClassUtils.isPresent("com.fasterxml.jackson.dataformat.xml.XmlMapper", RestTemplate.class.getClassLoader());

    private static final boolean gsonPresent =
            ClassUtils.isPresent("com.google.gson.Gson", RestTemplate.class.getClassLoader());

额外添加converters

    @Bean
    public RestTemplate restTemplate() {
        RestTemplate restTemplate = new RestTemplate(clientHttpRequestFactory());
        restTemplate.getMessageConverters().add(new FormHttpMessageConverter());
        return restTemplate;
    }

修改converter

    @Bean
    public RestTemplate restTemplate() {
        RestTemplate restTemplate = new RestTemplate();
        List<HttpMessageConverter<?>> converters = restTemplate.getMessageConverters();
        for(HttpMessageConverter converter : converters){
            if(converter instanceof MappingJackson2HttpMessageConverter) {
                MappingJackson2HttpMessageConverter jsonConverter = (MappingJackson2HttpMessageConverter)converter;
                jsonConverter.setObjectMapper(objectMapper());
                jsonConverter.setSupportedMediaTypes(ImmutableList.of(new MediaType("text", "ejson", MappingJackson2HttpMessageConverter.DEFAULT_CHARSET),
                        new MediaType("application", "json", MappingJackson2HttpMessageConverter.DEFAULT_CHARSET),
                        new MediaType("text", "javascript", MappingJackson2HttpMessageConverter.DEFAULT_CHARSET)));
            }
        }
        return restTemplate;
    }

或者

@Configuration
public class WebConfig extends WebMvcConfigurationSupport {

 @Bean
 public MappingJackson2HttpMessageConverter customJackson2HttpMessageConverter() {
  MappingJackson2HttpMessageConverter jsonConverter = new MappingJackson2HttpMessageConverter();
  ObjectMapper objectMapper = new ObjectMapper();
  objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
  jsonConverter.setObjectMapper(objectMapper);
  return jsonConverter;
 }
 
 @Override
 public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
  converters.add(customJackson2HttpMessageConverter());
  super.addDefaultHttpMessageConverters();
 }
}

doc

• Customizing HttpMessageConverters with Spring Boot and Spring MVC