Filter拦截器实现请求跨域转发
因为公司项目需求，项目中前端请求需要通过一个类似中转的服务转发(请求在该服务中会重新包装一些通用参数)
在使用Filter实现转发后特做一次记录
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package com.unicloud.cce.Filter; import com.alibaba.fastjson.JSON; import com.unicloud.cce测试数据mon.RestfulEntity; import com.unicloud.cce.service.CloudosService; import org.apache测试数据mons.io.IOUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.*; import org.springframework.stereotype.Component; import org.springframework.util.AntPathMatcher; import org.springframework.util.StringUtils; import org.springframework.web.client.RestTemplate; import javax.servlet.*; import javax.servlet.annotation.WebFilter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; import java.util.*;
/** * @author skyxt * Created 2019-06-11 18:46 * Email skyxt.yang@gmail测试数据 */ @WebFilter (filterName = "authFilter" , urlPatterns = { "/*" }) @Component public class RequestFilter implements Filter {
//该处配置需要转发的路径 public static final Set<String> FILTER_URL = Collections.unmodifiableSet( new HashSet<>(Arrays.asList( "/config/*" )));
@Autowired private RestTemplate restTemplate; @Autowired private CloudosService cloudosService; private final static Logger logger = LoggerFactory.getLogger(RequestFilter. class ); @Override public void init(FilterConfig filterConfig) throws ServletException { }
@Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { if (!(request instanceof HttpServletRequest) || !(response instanceof HttpServletResponse)) { return ; } HttpServletRequest req = (HttpServletRequest) request; HttpServletResponse rsp = (HttpServletResponse) response; AntPathMatcher matcher = new AntPathMatcher(); Optional<String> cloudIp = Optional.empty(); // for (String url : FILTER_URL) { // if (matcher.match(url, req.getRequestURI().substring(req.getContextPath().length()))) { // cloudIp = cloudosService.cloudosList("", "").stream().filter(cloudos -> // cloudos.getId().equals(((HttpServletRequest) request).getHeader("cloudId")) // ).map(Cloudos::getCloudIp).findFirst(); // } // } cloudIp = Optional.of( "localhost" ); if (cloudIp.isPresent()) { switch (req.getMethod()) { case "GET" : { request(req, rsp, HttpMethod.GET, cloudIp.get()); break ; } case "POST" : { request(req, rsp, HttpMethod.POST, cloudIp.get()); break ; } case "PUT" : { request(req, rsp, HttpMethod.PUT, cloudIp.get()); break ; } case "PATCH" : { request(req, rsp, HttpMethod.PATCH, cloudIp.get()); break ; } case "DELETE" : { request(req, rsp, HttpMethod.DELETE, cloudIp.get()); break ; } default :{ logger.error( "unknow request method:" + req.getMethod()); rsp.setCharacterEncoding( "UTF-8" ); try (PrintWriter out = rsp.getWriter()) { out.write( "请求方法未知" ); } catch (Exception e1) { logger.error(e1.getMessage() + e1); } } } } else { chain.doFilter(request, response); } }
@Override public void destroy() { }
private void request(HttpServletRequest req, HttpServletResponse rsp, HttpMethod method, String cloudIp) throws IOException { rsp.setCharacterEncoding( "UTF-8" ); String requestBody = IOUtils.toString(req.getInputStream(), "UTF-8" ); Object body = null ; if (StringUtils.hasText(requestBody)) { body = JSON.parse(requestBody); } HttpHeaders headers = new HttpHeaders(); Enumeration<String> headerNames = req.getHeaderNames(); while (headerNames.hasMoreElements()) { String name = headerNames.nextElement(); headers.add(name, req.getHeader(name)); } String url; if (StringUtils.hasText(req.getQueryString())) { url = String.format( "http://%s:15120%s?%s" , cloudIp, req.getRequestURI().substring(req.getContextPath().length()), req.getQueryString() ); } else { url = String.format( "http://%s:15120%s" , cloudIp, req.getRequestURI().substring(req.getContextPath().length()) ); } HttpEntity<Object> httpEntity = new HttpEntity<>(body, headers); ResponseEntity<RestfulEntity> exchange = null ; try { exchange = restTemplate.exchange( url, method, httpEntity, RestfulEntity. class ); } catch (Exception e) { logger.error(e.getMessage(), e); try (PrintWriter out = rsp.getWriter()) { out.write( "请求异常" ); } catch (Exception e1) { logger.error(e1.getMessage() + e1); } } if (exchange != null ) { exchange.getStatusCode(); rsp.setStatus(exchange.getStatusCodeValue()); exchange.getHeaders().entrySet().stream().forEach(entry -> { String value = entry.getValue().toString(); rsp.addHeader(entry.getKey(), value.substring( 1 , value.length()- 1 )); }); try (PrintWriter out = rsp.getWriter()) { out.write(JSON.toJSONString(exchange.getBody())); } catch (Exception e) { logger.error(e.getMessage(), e); } } else { logger.info( "error: URL:" + "http://" + cloudIp + ":15120" + req.getRequestURI().substring(req.getContextPath().length())); try (PrintWriter out = rsp.getWriter()) { out.write( "请求异常" ); } catch (Exception e1) { logger.error(e1.getMessage() + e1); } } } } |
使用filter解决跨域
在web.xml配置拦截器
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< filter > < filter-name >servletFilterTest</ filter-name > < filter-class >cn.test.intercepter.ServletFilterTest</ filter-class > </ filter > < filter-mapping > < filter-name >servletFilterTest</ filter-name > < url-pattern >/*</ url-pattern > </ filter-mapping > |
过滤器代码
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import org.springframework.web.bind.annotation.RequestMethod; import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; public class ServletFilterTest implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest; httpServletRequest.getSession(); HttpServletResponse httpResponse = (HttpServletResponse) servletResponse; httpResponse.setHeader( "Access-Control-Allow-Origin" , "*" ); httpResponse.setHeader( "Access-Control-Allow-Methods" , "*" ); httpResponse.setHeader( "Access-Control-Max-Age" , "3600" ); httpResponse.setHeader( "Access-Control-Allow-Headers" , "Origin, X-Requested-With, Content-Type, Accept, Connection, User-Agent, Cookie" ); httpResponse.setHeader( "Access-Control-Allow-Credentials" , "true" ); httpResponse.setHeader( "Content-type" , "application/json" ); httpResponse.setHeader( "Cache-Control" , "no-cache, must-revalidate" ); if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) { return ; } filterChain.doFilter(httpServletRequest, httpResponse); } @Override public void destroy() { } } |
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
原文链接：https://blog.csdn.net/weixin_37774620/article/details/91544007
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