SpringBoot自定義序列化的使用方式--WebMvcConfigurationSupport

SpringBoot自定義序列化的使用方式--WebMvcConfigurationSupport

場景及需求： 項目接入了SpringBoot開發，如今需求是服務端接口返回的字段若是爲空，那麼自動轉爲空字符串。

例如：
[
     {
         "id": 1,
         "name": null
     },
     {
         "id": 2,
         "name": "xiaohong"
     }
]

如上，格式化後的返回內容應該爲：
[
     {
         "id": 1,
         "name": ""
     },
     {
         "id": 2,
         "name": "xiaohong"
     }
]

 

這裏直接給出解決方案代碼，這裏支持FastJson和Jackson配置序列化的方式：

@Configuration
public class WebCatMvcConfiguration extends WebMvcConfigurationSupport {

    @Override
    protected void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
        ObjectMapper objectMapper = new ObjectMapper();
        SimpleModule module = new SimpleModule();
        module.addSerializer(new ToStringSerializer(Long.TYPE));
        module.addSerializer(new ToStringSerializer(Long.class));
        module.addSerializer(new ToStringSerializer(BigInteger.class));
        objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
            @Override
            public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
                jsonGenerator.writeString("");
            }
        });
        objectMapper.registerModule(module);
        converter.setObjectMapper(objectMapper);

        //這裏是fastJSON的配置方式，更多的內容能夠查看SerializerFeature
//        FastJsonHttpMessageConverter converter = new FastJsonHttpMessageConverter();
//        converter.setFeatures(SerializerFeature.WriteNullStringAsEmpty, SerializerFeature.WriteNullNumberAsZero,
//                SerializerFeature.WriteNullBooleanAsFalse, SerializerFeature.WriteNullListAsEmpty);
        converters.add(converter);
    }

}

最後咱們也能夠了解一下：WebMvcConfigurationSupport類
下面是它的官方文檔描述：

public class WebMvcConfigurationSupportextends Objectimplements ApplicationContextAware, ServletContextAware

This is the main class providing the configuration behind the MVC Java config. It is typically imported by adding @EnableWebMvc to an application@Configuration class. An alternative more advanced option is to extend directly from this class and override methods as necessary remembering to add@Configuration to the subclass and @Bean to overridden @Bean methods. For more details see the Javadoc of @EnableWebMvc.

This class registers the following HandlerMappings:

 

• RequestMappingHandlerMapping ordered at 0 for mapping requests to annotated controller methods.

• HandlerMapping ordered at 1 to map URL paths directly to view names.

• BeanNameUrlHandlerMapping ordered at 2 to map URL paths to controller bean names.

• HandlerMapping ordered at Integer.MAX_VALUE-1 to serve static resource requests.

• HandlerMapping ordered at Integer.MAX_VALUE to forward requests to the default servlet.

Registers these HandlerAdapters:

• RequestMappingHandlerAdapter for processing requests with annotated controller methods.

• HttpRequestHandlerAdapter for processing requests with HttpRequestHandlers.

• SimpleControllerHandlerAdapter for processing requests with interface-based Controllers.

Registers a HandlerExceptionResolverComposite with this chain of exception resolvers:

• ExceptionHandlerExceptionResolver for handling exceptions through @ExceptionHandler methods.

• ResponseStatusExceptionResolver for exceptions annotated with @ResponseStatus.

• DefaultHandlerExceptionResolver for resolving known Spring exception types

Registers an AntPathMatcher and a UrlPathHelper to be used by:

• the RequestMappingHandlerMapping,

• the HandlerMapping for ViewControllers

• and the HandlerMapping for serving resources

Note that those beans can be configured with a PathMatchConfigurer.

Both the RequestMappingHandlerAdapter and the ExceptionHandlerExceptionResolver are configured with default instances of the following by default:

• a ContentNegotiationManager

• a DefaultFormattingConversionService

• a OptionalValidatorFactoryBean if a JSR-303 implementation is available on the classpath

• a range of HttpMessageConverters depending on the third-party libraries available on the classpath.
  
  
  

 

分類: SpringBoot

好文要頂 關注我 收藏該文  

一枝花算不算浪漫