使用WebMvcConfigurer配置SpringMVC过程

@Configuration
public class WebMvcConfg implements WebMvcConfigurer {}

@Configuration
public class WebMvcConfg extends WebMvcConfigurationSupport {}

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")  //浏览器允许所有的域访问 / 注意 * 不能满足带有cookie的访问,Origin 必须是全匹配
                .allowCredentials(true)   // 允许带cookie访问
                .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")
                 .allowedHeaders("token")
                .maxAge(3600);
    }

  @Override
  public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
    // 是否通过请求Url的扩展名来决定media type
    configurer.favorPathExtension(false);
    //不检查Accept请求头    设置默认的media type
configurer.ignoreAcceptHeader(true).defaultContentType(MediaType.APPLICATION_JSON_UTF8);
  }

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        // 绑定指定URL访问的view名称，这行的意思是在访问/路径时会自动跳转到index.html;如/login则不受影响
        registry.addViewController("/").setViewName("forward:/index.html");
    }

     /**
 * 消息内容转换配置
 */
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    //StringHttpMessageConverter默认使用的字符集是ISO-8859-1,改为输出的JSON字符串为UTF-8字符集
    converters.add(new StringHttpMessageConverter(StandardCharsets.UTF_8));
    
    //添加fastjson消息转换器
    converters.add(fastJsonHttpMessageConverters());
}

/**
 * 引入Fastjson解析json，不使用默认的jackson,必须在pom.xml引入fastjson的jar包，并且版必须大于1.2.10
 *
 * @return
 */
@Bean
public FastJsonHttpMessageConverter fastJsonHttpMessageConverters() {
    //1、定义一个convert转换消息的对象
    FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();

    //2、添加fastjson的配置信息
    FastJsonConfig fastJsonConfig = new FastJsonConfig();

    SerializerFeature[] serializerFeatures = new SerializerFeature[]{
            //    输出key是包含双引号
            //SerializerFeature.QuoteFieldNames,
            //    是否输出为null的字段,若为null 则显示该字段
            SerializerFeature.WriteMapNullValue,
            //    数值字段如果为null，则输出为0
            SerializerFeature.WriteNullNumberAsZero,
            //     List字段如果为null,输出为[],而非null
            SerializerFeature.WriteNullListAsEmpty,
            //    字符类型字段如果为null,输出为"",而非null
            SerializerFeature.WriteNullStringAsEmpty,
            //    Boolean字段如果为null,输出为false,而非null
            SerializerFeature.WriteNullBooleanAsFalse,
            //    Date的日期转换器
            SerializerFeature.WriteDateUseDateFormat,
            //    循环引用（如果不配置有可能会进入死循环）
            SerializerFeature.DisableCircularReferenceDetect,
            //    格式化JSON
            SerializerFeature.PrettyFormat
    };


    fastJsonConfig.setSerializerFeatures(serializerFeatures);
    fastJsonConfig.setCharset(Charset.forName("UTF-8"));


    //3.解决乱码问题。定义响应的MIME类型，设置响应的content-type为application/json;charset=UTF-8
    List<MediaType> fastMediaType = new ArrayList<>();
    fastMediaType.add(MediaType.valueOf(MediaType.APPLICATION_JSON_VALUE));

    //4.converter消息转换器添加配置信息
    fastConverter.setSupportedMediaTypes(fastMediaType);

    //5、在convert中添加配置信息
    fastConverter.setFastJsonConfig(fastJsonConfig);

    return fastConverter;
}

@Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        converters.add(customerMappingJackson2HttpMessageConverter());
    }

    @Bean
    public MappingJackson2HttpMessageConverter customerMappingJackson2HttpMessageConverter(){
        MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();
        //设置日期格式

        ObjectMapper objectMapper = messageConverter.getObjectMapper();
        SimpleDateFormat smt = new SimpleDateFormat("yyyy-MM-dd");
        objectMapper.setDateFormat(smt);
        messageConverter.setObjectMapper(objectMapper);

        //设置中文编码格式
        List<MediaType> list = new ArrayList<MediaType>();
        list.add(MediaType.APPLICATION_JSON);
        messageConverter.setSupportedMediaTypes(list);
        return messageConverter;
    }

    @Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        MappingJackson2HttpMessageConverter
                mappingJackson2HttpMessageConverter =
                new MappingJackson2HttpMessageConverter();

        // 调整ObjectMapper对象序列化行为
        ObjectMapper objectMapper = mappingJackson2HttpMessageConverter.getObjectMapper();
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

        mappingJackson2HttpMessageConverter.setObjectMapper(objectMapper);
        converters.add(0,mappingJackson2HttpMessageConverter);

    }

@Configuration
public class JacksonConfig implements WebMvcConfigurer {

    @Value("${xss.enabled:false}")
    private boolean enableXss;

    @Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        MappingJackson2HttpMessageConverter jackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();

        ObjectMapper objectMapper = jackson2HttpMessageConverter.getObjectMapper();

        SimpleModule simpleModule = new SimpleModule();

        //Long类型序列化成字符串，避免Long精度丢失
        simpleModule.addSerializer(Long.class, ToStringSerializer.instance);
//        simpleModule.addSerializer(Long.TYPE, ToStringSerializer.instance);

        // XSS序列化
        if (enableXss) {
            simpleModule.addDeserializer(String.class, new XssJacksonDeserializer());
        }

        // Date
        simpleModule.addSerializer(Date.class, new JacksonDateSerializer());
        simpleModule.addDeserializer(Date.class, new JacksonDateDeserializer());
        simpleModule.addSerializer(LocalDateTime.class, new JacksonLocalDateTimeSerializer());
        simpleModule.addDeserializer(LocalDateTime.class, new JacksonLocalDateTimeDeserializer());

        objectMapper.registerModule(simpleModule)
                .registerModule(new JavaTimeModule())
                .registerModule(new ParameterNamesModule())
                .registerModule(new Jdk8Module());

        jackson2HttpMessageConverter.setObjectMapper(objectMapper);

        //放到第一个
        converters.add(0, jackson2HttpMessageConverter);
    }

}

  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
    // 10 days
    addCacheControl(registry, "img", 864000);
    addCacheControl(registry, "vendor", 864000);
    // 1 day
    addCacheControl(registry, "scripts", 86400);
    addCacheControl(registry, "styles", 86400);
    addCacheControl(registry, "views", 86400);
  }

  private void addCacheControl(ResourceHandlerRegistry registry, String folder, int cachePeriod) {
    registry.addResourceHandler(String.format("/%s/**", folder))
        .addResourceLocations(String.format("classpath:/static/%s/", folder))
        .setCachePeriod(cachePeriod);
  }