Spring Boot 静态资源配置； 拦截器、过滤器

静态资源配置

• yml方式 ，简易快捷配置

# spring boot版本 > 2.5.0
spring:
  web:
    resources:
      # 路径值为: file:img/ ↓
      # 开发时,指向src同级目录 /img
      # 部署时，在jar包同级目录
      # file:../img/ ,代表上一级目录
      # 资源匹配路径都为 /** , eg: localhost:8080/1.jpg
      static-locations: file:img/,file:upload/
  #配置整体的资源映射路径    
  #mvc:
    #static-path-pattern: /**

# 过往版本 spring boot
spring:
  resources:
    static-locations: 

配置类方式：

• 可以灵活配置静态资源映射；

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/upload/**")
                .addResourceLocations("file:upload/");
                
        registry.addResourceHandler("/img/**")
                .addResourceLocations("file:img/");        
    }
}

WebMvcConfigurer ：Spring接口配置类，常见功能配置项

拦截器

• 好比进停车场是拦住车，是可以控制用户的访问的；如用户的权限访问控制

过滤器

• 好比 水过滤器一样，去除掉部分不需要的东西

请求 -> 过滤器 -> 拦截器

拦截器实现：

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Component
public class MyInterCeptor implements HandlerInterceptor {
    private String id;
    //return true 放行
    //拦截
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("-------拦截器：处理前-------");
        return true;
        //return HandlerInterceptor.super.preHandle(request, response, handler);
    }

    //拦截日志
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("拦截器：处理后: ");
        HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("-------拦截器：资源清理-------");
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }

}

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {

    @Resource
    private MyInterCeptor interCeptor;
    /**
     * 注册自定义拦截器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //可以多个拦截器
        InterceptorRegistration interceptorRegistration = registry.addInterceptor(interCeptor);
        //可以设置多个路径拦截
        interceptorRegistration.addPathPatterns("/**"); //拦截全部
    }
}

过滤器实现：

import org.springframework.core.annotation.Order;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

@Order(1)
@WebFilter(filterName = "myFilter",urlPatterns = {"/*"})
public class MyFilter implements Filter {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("过滤器：进入目标资源之前先干点啥");
        filterChain.doFilter(servletRequest, servletResponse);
    }

}

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class FilterConfig {
    @Bean
    public FilterRegistrationBean registFilter(){
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        registrationBean.setFilter(new MyFilter());
        registrationBean.addUrlPatterns("/*");
        registrationBean.setName("Filter1");
        registrationBean.setOrder(1);
        return registrationBean;
    }
}