在日常项目中，有时候会根据一些规则/标识进行Http路由匹配，下面我实现一个简单的Http根据systemCode自动路由；
- Controller
- Service
- Properties
- Properties类
- Yaml
- 测试
- 路由到baidu
Controller
import com.example.demo.service.GatewayRoutingService;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@RestController
@RequestMapping("/gateway-routing")
public class GatewayRoutingController {private Logger log = LoggerFactory.getLogger(GatewayRoutingController.class);@Autowiredprivate GatewayRoutingService service;/*** 根据systemCode，自行匹配路由到systemCode对应的域名上** @param request* @param response*/@RequestMapping("/invoke/**")public void invoke(HttpServletRequest request, HttpServletResponse response) {String systemCode = request.getHeader("system-code");if (StringUtils.isEmpty(systemCode)) {// return 404response.setStatus(HttpServletResponse.SC_NOT_FOUND);return;}try {// 路由调用service.invoke(systemCode, request, response);} catch (Exception e) {log.info("genericInvoke>>>exception", e);throw new RuntimeException("系统错误，请联系管理");}}
}
Service
import com.example.demo.config.RequestInvokeProperties;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpMethod;
import org.springframework.http.client.ClientHttpRequest;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.stereotype.Service;
import org.springframework.util.Assert;
import org.springframework.util.StreamUtils;import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;@Service
public class GatewayRoutingService {private Logger log = LoggerFactory.getLogger(GatewayRoutingService.class);/*** 系统域名映射 key ：系统唯一标识， value 系统*/@Autowiredprivate RequestInvokeProperties properties;/*** 路由调用*/public void invoke(String systemCode, HttpServletRequest request, HttpServletResponse response) throws Exception {// 解析获取真实请求路径final URI realUrl = this.resolveRealUrl(systemCode, request);final HttpMethod httpMethod = HttpMethod.resolve(request.getMethod());if (httpMethod == null || realUrl == null) {throw new RuntimeException("当前请求不合法, 无法转发");}log.info("routing and forwarding>>>originalUrl = {}, realUrl = {}", request.getRequestURI(), realUrl);ClientHttpRequest delegateRequest = new SimpleClientHttpRequestFactory().createRequest(realUrl, httpMethod);// set headersetRequestHeader(request, delegateRequest);// set bodysetRequestBody(request, delegateRequest);// http调用try (ClientHttpResponse clientHttpResponse = delegateRequest.execute();ServletOutputStream responseOutputStream = response.getOutputStream()) {response.setStatus(clientHttpResponse.getStatusCode().value());clientHttpResponse.getHeaders().forEach((key, values) -> {// 处理响应头重复情况，在请求返回时该响应头会出现重复，postman 调用成功，但是实际前端调用会出错if (!"Transfer-Encoding".equalsIgnoreCase(key)) {values.forEach(value -> response.setHeader(key, value));}});// 拷贝响应流ioCopy(clientHttpResponse.getBody(), responseOutputStream, 2024);}}/*** 拷贝响应流** @param in* @param out*/private long ioCopy(InputStream in, OutputStream out, int bufferSize) throws IOException {Assert.notNull(in, "InputStream is null !");Assert.notNull(out, "OutputStream is null !");long size = 0L;try {if (bufferSize <= 0) {bufferSize = 2048;}byte[] buffer = new byte[bufferSize];int readSize;while ((readSize = in.read(buffer)) != -1) {out.write(buffer, 0, readSize);size += (long) readSize;out.flush();}} finally {in.close();out.close();}return size;}/*** 解析获取真实请求路径** @param system* @param request* @return*/private URI resolveRealUrl(String system, HttpServletRequest request) throws URISyntaxException, UnsupportedEncodingException {if (properties.getSystemMap() == null || properties.getSystemMap().isEmpty()) {return null;}// 获取真实的请求url：去除前缀 /invoke/StringBuilder requestUrl = new StringBuilder(StringUtils.substringAfter(request.getRequestURI(), "/invoke/"));// 根据systemCode获取对应的域名String domain = properties.getSystemMap().get(system);if (StringUtils.isNoneBlank(requestUrl.toString(), domain)) {final Enumeration<String> parameterNames = request.getParameterNames();StringBuilder uriVariables = new StringBuilder("?");while (parameterNames.hasMoreElements()) {// 转义部分特殊字符，如果请求参数里带有 +、空格等不转义请求路由过去会出问题final String parameterName = URLEncoder.encode(parameterNames.nextElement(), "UTF-8");final String parameter = URLEncoder.encode(request.getParameter(parameterName), "UTF-8");uriVariables.append(parameterName).append("=").append(parameter).append("&");}domain = domain.endsWith("/") ? domain : domain + "/";return new URI(domain + requestUrl + (uriVariables.length() == 1 ? "" : uriVariables.substring(0, uriVariables.length() - 1)));}return null;}/*** 设置请求体** @throws IOException*/private void setRequestBody(HttpServletRequest request, ClientHttpRequest delegateRequest) throws IOException {StreamUtils.copy(request.getInputStream(), delegateRequest.getBody());}/*** 设置请求头*/private void setRequestHeader(HttpServletRequest request, ClientHttpRequest delegateRequest) {Enumeration<String> headerNames = request.getHeaderNames();// 设置请求头while (headerNames.hasMoreElements()) {String headerName = headerNames.nextElement();Enumeration<String> header = request.getHeaders(headerName);List<String> arr = new ArrayList<>();while (header.hasMoreElements()) {arr.add(header.nextElement());}delegateRequest.getHeaders().addAll(headerName, arr);}if (!delegateRequest.getHeaders().containsKey("Content-Type")) {delegateRequest.getHeaders().add("Content-Type", "application/json; charset=utf-8");}}
}
Properties
Properties类
@Data
@Component
@ConfigurationProperties(prefix = "request.invoke")
public class RequestInvokeProperties {private Map<String, String> systemMap;
}
Yaml
request:invoke:systemMap:baidu: http://www.baidu.com/
测试
路由到baidu
请求：
curl --location --request GET 'http://localhost:8080/gateway-routing/invoke/s?wd=spring' \
--header 'system-code: baidu' \
--header 'User-Agent: Apifox/1.0.0 (https://apifox.com)' \
--header 'Content-Type: application/json' \
--header 'Accept: */*' \
--header 'Host: localhost:8080' \
--header 'Connection: keep-alive' \
--data-raw ''
实际请求：
http://www.baidu.com/s?wd=spring
(unity Lab4))
