spring?boot使用攔截器修改請求URL域名?換?IP?訪問的方法

更新時(shí)間：2022年09月17日 11:09:20 作者：OAK社區(qū)

Spring Interceptor是一個非常類似于Servlet Filter 的概念，這篇文章主要介紹了spring?boot使用攔截器修改請求URL域名?換?IP?訪問的相關(guān)知識,需要的朋友可以參考下

Interceptor 介紹

攔截器(Interceptor)同 Filter 過濾器一樣，它倆都是面向切面編程——AOP 的具體實(shí)現(xiàn)（AOP切面編程只是一種編程思想而已）。

你可以使用 Interceptor 來執(zhí)行某些任務(wù)，例如在 Controller 處理請求之前編寫日志，添加或更新配置…

在 Spring中，當(dāng)請求發(fā)送到 Controller 時(shí)，在被Controller處理之前，它必須經(jīng)過 Interceptors（0或多個）。

Spring Interceptor是一個非常類似于Servlet Filter 的概念。

Interceptor 作用

日志記錄：記錄請求信息的日志，以便進(jìn)行信息監(jiān)控、信息統(tǒng)計(jì)、計(jì)算 PV（Page View）等；
權(quán)限檢查：如登錄檢測，進(jìn)入處理器檢測是否登錄；
性能監(jiān)控：通過攔截器在進(jìn)入處理器之前記錄開始時(shí)間，在處理完后記錄結(jié)束時(shí)間，從而得到該請求的處理時(shí)間。（反向代理，如 Apache 也可以自動記錄）
通用行為：讀取 Cookie 得到用戶信息并將用戶對象放入請求，從而方便后續(xù)流程使用，還有如提取 Locale、Theme 信息等，只要是多個處理器都需要的即可使用攔截器實(shí)現(xiàn)。

自定義 Interceptor

如果你需要自定義 Interceptor 的話必須實(shí)現(xiàn) org.springframework.web.servlet.HandlerInterceptor接口或繼承 org.springframework.web.servlet.handler.HandlerInterceptorAdapter類，并且需要重寫下面下面 3 個方法：

preHandler(HttpServletRequest request, HttpServletResponse response, Object handler) 方法在請求處理之前被調(diào)用。該方法在 Interceptor 類中最先執(zhí)行，用來進(jìn)行一些前置初始化操作或是對當(dāng)前請求做預(yù)處理，也可以進(jìn)行一些判斷來決定請求是否要繼續(xù)進(jìn)行下去。該方法的返回至是 Boolean 類型，當(dāng)它返回 false 時(shí)，表示請求結(jié)束，后續(xù)的 Interceptor 和 Controller 都不會再執(zhí)行；當(dāng)它返回為 true 時(shí)會繼續(xù)調(diào)用下一個 Interceptor 的 preHandle 方法，如果已經(jīng)是最后一個 Interceptor 的時(shí)候就會調(diào)用當(dāng)前請求的 Controller 方法。
postHandler(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) 方法在當(dāng)前請求處理完成之后，也就是 Controller 方法調(diào)用之后執(zhí)行，但是它會在 DispatcherServlet 進(jìn)行視圖返回渲染之前被調(diào)用，所以我們可以在這個方法中對 Controller 處理之后的 ModelAndView 對象進(jìn)行操作。
afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handle, Exception ex) 方法需要在當(dāng)前對應(yīng)的 Interceptor 類的 postHandler 方法返回值為 true 時(shí)才會執(zhí)行。顧名思義，該方法將在整個請求結(jié)束之后，也就是在 DispatcherServlet 渲染了對應(yīng)的視圖之后執(zhí)行。此方法主要用來進(jìn)行資源清理。

接下來結(jié)合實(shí)際代碼進(jìn)行學(xué)習(xí)。

案例1 :域名換IP訪問

package com.config;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.support.HttpRequestWrapper;
import org.springframework.stereotype.Component;
import org.springframework.web.util.UriComponentsBuilder;
import java.io.IOException;
import java.net.URI;
@Component
public class Interceptor implements ClientHttpRequestInterceptor {
    /**
     * Intercept the given request, and return a response. The given {@link ClientHttpRequestExecution} allows
     * the interceptor to pass on the request and response to the next entity in the chain.
     *
     * <p>A typical implementation of this method would follow the following pattern:
     * <ol>
     * <li>Examine the {@linkplain HttpRequest request} and body</li>
     * <li>Optionally {@linkplain HttpRequestWrapper wrap} the request to filter HTTP attributes.</li>
     * <li>Optionally modify the body of the request.</li>
     * <li><strong>Either</strong>
     * <ul>
     * <li>execute the request using {@link ClientHttpRequestExecution#execute(HttpRequest, byte[])},</li>
     * <strong>or</strong>
     * <li>do not execute the request to block the execution altogether.</li>
     * </ul>
     * <li>Optionally wrap the response to filter HTTP attributes.</li>
     * </ol>
     *
     * @param request   the request, containing method, URI, and headers
     * @param body      the body of the request
     * @param execution the request execution
     * @return the response
     * @throws IOException in case of I/O errors
     */
    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        String str = request.getURI().toString();
        String str1 = str.replace("https://baidu.com", "http://39.156.66.10:8080");
        URI newUri = UriComponentsBuilder.fromUri(URI.create(str)).build().toUri();
         return execution.execute(new UriModifyHttpRequestWrapper(request, newUri), body);
    }
    private static class UriModifyHttpRequestWrapper extends HttpRequestWrapper {
        private final URI uri;
        public UriModifyHttpRequestWrapper(HttpRequest request, URI uri) {
            super(request);
            this.uri = uri;
        }
        @Override
        public URI getURI() {
            return uri;
        }
    }
}

案例2: erverWebExchange通過攔截器修改請求url

@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain)
{
    ServerHttpRequest str = exchange.getRequest();
    //新url
    String newPath ="/system/loanOrg/list";
    ServerHttpRequest newRequest = str.mutate().path(newPath).build();
    exchange.getAttributes().put("path", newRequest.getURI());
    return chain.filter(exchange.mutate() .request(newRequest).build());
}

案例3: 將請求路徑中/idea都去掉

1.定義攔截器

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
@Component
public class GlobalInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        HttpServletResponseWrapper httpResponse = new HttpServletResponseWrapper((HttpServletResponse) response);
        System.out.println(request.getRequestURI());
        String path=request.getRequestURI();
        if(path.indexOf("/idea")>-1){
            path = path.replaceAll("/idea","");
            request.getRequestDispatcher(path).forward(request,response);
        }
 
        return true;
    }
}

2.定義WebMvcConfig

import com.GlobalInterceptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Autowired
    GlobalInterceptor globalInterceptor;
 
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(globalInterceptor).addPathPatterns("/idea/**");
    }
}

案例4: SpringBoot 利用過濾器Filter修改請求url地址

要求：

代碼中配置的url路徑為http://127.0.0.1/api/asso

現(xiàn)在要求http://127.0.0.1/asso 也可以同樣訪問同一個conroller下面的method,并且要求參數(shù)全部跟隨

代碼：

package com.framework.filter;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

/**
 * 修改請求路由，當(dāng)進(jìn)入url為/a/b時(shí)，將其url修改為/api/a/b
 *  
 **/
public class UrlFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void destroy() {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest)request;
        HttpServletResponseWrapper httpResponse = new HttpServletResponseWrapper((HttpServletResponse) response);
        System.out.println(httpRequest.getRequestURI());
        String path=httpRequest.getRequestURI();
        if(path.indexOf("/api/")<0){
            path="/api"+path;
            System.out.println(path);
            httpRequest.getRequestDispatcher(path).forward(request,response);
        }
       else {
            chain.doFilter(request,response);

        }
        return;
    }
}

這個類必須繼承Filter類，這個是Servlet的規(guī)范。有了過濾器類以后，以前的web項(xiàng)目可以在web.xml中進(jìn)行配置，但是spring boot項(xiàng)目并沒有web.xml這個文件，那怎么配置？在Spring boot中，我們需要FilterRegistrationBean來完成配置。

其實(shí)現(xiàn)過程如下：

package com.shitou.huishi.framework.filter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
 * Created by qhong on 2018/5/16 15:28
 **/
@Configuration
public class FilterConfig {
    @Bean
    public FilterRegistrationBean registFilter() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new UrlFilter());
        registration.addUrlPatterns("/*");
        registration.setName("UrlFilter");
        registration.setOrder(1);
        return registration;
    }
}

案例5.攔截器: WebMvcConfigurerAdapter攔截器

攔截所有請求

	@Configuration
	public class CustMvcConfigurerAdapter extends WebMvcConfigurerAdapter {
    @Autowired
    private CustInterceptor custInterceptor;
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(custInterceptor).addPathPatterns("/**");
    }
}

排除指定路徑

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(custInterceptor).addPathPatterns("/**").excludePathPatterns("/select/**");
    }

攔截指定路徑

@Override
public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(custInterceptor).addPathPatterns("/user/**");
}

CustInterceptor具體攔截類

@Component
public class CustInterceptor extends HandlerInterceptorAdapter {
	   @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        boolean needLogin = needLogin(request);
        if (!needLogin) {
            return true;
        }
        boolean isLogin = checkLogin(request, response);
        return isLogin;
    }
}