springboot自定义静态资源代理WebMvcConfigurerAdapter详解和过期后的替代方案WebMvcConfigurer

最常用的跨域和静态资源代理

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {

        //Windows下
        registry.addResourceHandler("/uploads2
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        // 设置允许跨域的路由
        registry.addMapping("
public void addCorsMappings(CorsRegistry registry) ;


void addInterceptors(InterceptorRegistry registry);


void configureViewResolvers(ViewResolverRegistry registry);


void configureContentNegotiation(ContentNegotiationConfigurer configurer);


void addViewControllers(ViewControllerRegistry registry);


void addResourceHandlers(ResourceHandlerRegistry registry);


void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer);

一、addInterceptors：拦截器

• addInterceptor：须要一个实现HandlerInterceptor接口的拦截器实例
• addPathPatterns：用于设置拦截器的过滤路径规则

excludePathPatterns：用于设置不须要拦截的过滤规则java

@Override
public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new MyInterceptor()).addPathPatterns("
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/toLogin").setViewName("login");
        registry.addViewController("/").setViewName("/index");
        registry.addViewController("/login").setViewName("forward:/index.html");
        super.addViewControllers(registry);
    }

四、resourceViewResolver：视图解析器

@Bean
public InternalResourceViewResolver resourceViewResolver()
{
	InternalResourceViewResolver internalResourceViewResolver = new InternalResourceViewResolver();
	//请求视图文件的前缀地址
	internalResourceViewResolver.setPrefix("/WEB-INF/jsp/");
	//请求视图文件的后缀
	internalResourceViewResolver.setSuffix(".jsp");
	return internalResourceViewResolver;
}


@Override
public void configureViewResolvers(ViewResolverRegistry registry) {
	super.configureViewResolvers(registry);
	registry.viewResolver(resourceViewResolver());
	
}

五、configureMessageConverters：信息转换器

@Override
public void configureMessageConverters(List> converters) {
    //调用父类的配置
    super.configureMessageConverters(converters);
    //建立fastJson消息转换器
    FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
    //建立配置类
    FastJsonConfig fastJsonConfig = new FastJsonConfig();
    //修改配置返回内容的过滤
    fastJsonConfig.setSerializerFeatures(
            SerializerFeature.DisableCircularReferenceDetect,
            SerializerFeature.WriteMapNullValue,
            SerializerFeature.WriteNullStringAsEmpty
    );
    fastConverter.setFastJsonConfig(fastJsonConfig);
    //将fastjson添加到视图消息转换器列表内
    converters.add(fastConverter);

}

六、addResourceHandlers：静态资源

@Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        //自定义项目内目录
        //registry.addResourceHandler("/my/**").addResourceLocations("classpath:/my/");
        //指向外部目录
        registry.addResourceHandler("/my/**").addResourceLocations("file:E:/my/");
        super.addResourceHandlers(registry);
    }

3、使用WebMvcConfigurerAdapter
一、过期方式：继承WebMvcConfigurerAdapter
　该方法在spring boot 2.0，Spring 5.0 以后，已经被废弃 spring

@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
    //TODO
}

二、代替方案
　①直接实现WebMvcConfigurerjson

@Configuration
public class WebMvcConfg implements WebMvcConfigurer {
    //TODO
}

②直接继承WebMvcConfigurationSupport跨域

@Configuration
public class WebMvcConfg extends WebMvcConfigurationSupport {
    //TODO
}

查看源码发现: WebMvcConfigurerAdapter只是对WebMvcCofigurer的空实现app

WebMvcConfigurationSupport与WebMvcConfigurerAdapter、接口WebMvcConfigurer处于同一个目录下框架

WebMvcConfigurationSupport包含WebMvcConfigurer里面的方法，且WebMvcConfigurationSupport的实现的方法更全面jsp

可是继承WebMvcConfigurationSupport会发现Spring Boot的WebMvc自动配置失效(WebMvcAutoConfiguration自动化配置)，致使没法视图解析器没法解析并返回到对应的视图。