src/main/java/com/ericsson/gerrit/plugins/goimport/GoImportFilter.java - plugins/go-import - Git at Google

 // Copyright (C) 2017 The Android Open Source Project
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 // http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package com.ericsson.gerrit.plugins.goimport;

 import com.google.gerrit.httpd.AllRequestFilter;
 import com.google.gerrit.httpd.HtmlDomUtil;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.config.CanonicalWebUrl;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectState;
 import com.google.gwtexpui.server.CacheHeaders;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;

 import java.io.IOException;
 import java.io.OutputStream;
 import java.net.URI;
 import java.net.URISyntaxException;

 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 @Singleton
 public class GoImportFilter extends AllRequestFilter {

   private static final String PAGE_404 = "<!DOCTYPE html>\n"
       + "<html>\n"
       + "<head>\n"
       + "  <title>Gerrit-Go-Import</title>\n"
       + "  <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/>\n"
       + "</head>\n"
       + "<body>\n"
       + "NOT FOUND\n"
       + "</body>\n"
       + "</html>";

   private static final String PAGE_200 = "<!DOCTYPE html>\n"
       + "<html>\n"
       + "<head>\n"
       + "  <title>Gerrit-Go-Import</title>\n"
       + "  <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/>\n"
       + "  <meta name=\"go-import\" content=\"${content}\"/>\n"
       + "</head>\n"
       + "<body>\n"
       + "<div>\n"
       + "  Gerrit-Go-Import\n"
       + "</div>\n"
       + "</body>\n"
       + "</html>";

   private final ProjectCache projectCache;
   final String webUrl;
   final String projectPrefix;

   @Inject
   GoImportFilter(ProjectCache projectCache,
       @CanonicalWebUrl String webUrl)
       throws URISyntaxException {
     this.projectCache = projectCache;
     this.webUrl = webUrl.replaceFirst("/?$", "/");
     this.projectPrefix = generateProjectPrefix();
   }

   private String generateProjectPrefix() throws URISyntaxException {
     URI uri = new URI(webUrl);
     return uri.getHost() + (uri.getPort() == -1 ? "" : ":" + uri.getPort())
         + uri.getPath();
   }

   @Override
   public void doFilter(ServletRequest request, ServletResponse response,
       FilterChain chain) throws IOException, ServletException {
     if (request instanceof HttpServletRequest) {
       HttpServletRequest req = (HttpServletRequest) request;
       HttpServletResponse rsp = (HttpServletResponse) response;
       String servletPath = req.getServletPath();
       String goGet = req.getParameter("go-get");
       if ("1".equals(goGet)) {
         String projectName = getProjectName(servletPath);

         byte[] tosend = PAGE_404.getBytes();
         rsp.setStatus(404);
         if (projectExists(projectName)) {
           tosend = PAGE_200.replace("${content}", getContent(projectName))
               .getBytes();
           rsp.setStatus(200);
         }

         CacheHeaders.setNotCacheable(rsp);
         rsp.setContentType("text/html");
         rsp.setCharacterEncoding(HtmlDomUtil.ENC.name());
         rsp.setContentLength(tosend.length);
         try (OutputStream out = rsp.getOutputStream()) {
           out.write(tosend);
         }
       } else {
         chain.doFilter(request, response);
       }
     } else {
       chain.doFilter(request, response);
     }

   }

   private String getProjectName(String servletPath) {
     return servletPath.replaceFirst("/", "");
   }

   private CharSequence getContent(String projectName) {
     return projectPrefix + projectName + " git " + webUrl  + "a/" + projectName;
   }

   private boolean projectExists(String projectName) {
     ProjectState p = projectCache.get(new Project.NameKey(projectName));
     return p != null;
   }
 }
	// Copyright (C) 2017 The Android Open Source Project
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package com.ericsson.gerrit.plugins.goimport;

	import com.google.gerrit.httpd.AllRequestFilter;
	import com.google.gerrit.httpd.HtmlDomUtil;
	import com.google.gerrit.reviewdb.client.Project;
	import com.google.gerrit.server.config.CanonicalWebUrl;
	import com.google.gerrit.server.project.ProjectCache;
	import com.google.gerrit.server.project.ProjectState;
	import com.google.gwtexpui.server.CacheHeaders;
	import com.google.inject.Inject;
	import com.google.inject.Singleton;

	import java.io.IOException;
	import java.io.OutputStream;
	import java.net.URI;
	import java.net.URISyntaxException;

	import javax.servlet.FilterChain;
	import javax.servlet.ServletException;
	import javax.servlet.ServletRequest;
	import javax.servlet.ServletResponse;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	@Singleton
	public class GoImportFilter extends AllRequestFilter {

	private static final String PAGE_404 = "<!DOCTYPE html>\n"
	+ "<html>\n"
	+ "<head>\n"
	+ " <title>Gerrit-Go-Import</title>\n"
	+ " <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/>\n"
	+ "</head>\n"
	+ "<body>\n"
	+ "NOT FOUND\n"
	+ "</body>\n"
	+ "</html>";

	private static final String PAGE_200 = "<!DOCTYPE html>\n"
	+ "<html>\n"
	+ "<head>\n"
	+ " <title>Gerrit-Go-Import</title>\n"
	+ " <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/>\n"
	+ " <meta name=\"go-import\" content=\"${content}\"/>\n"
	+ "</head>\n"
	+ "<body>\n"
	+ "<div>\n"
	+ " Gerrit-Go-Import\n"
	+ "</div>\n"
	+ "</body>\n"
	+ "</html>";

	private final ProjectCache projectCache;
	final String webUrl;
	final String projectPrefix;

	@Inject
	GoImportFilter(ProjectCache projectCache,
	@CanonicalWebUrl String webUrl)
	throws URISyntaxException {
	this.projectCache = projectCache;
	this.webUrl = webUrl.replaceFirst("/?$", "/");
	this.projectPrefix = generateProjectPrefix();
	}

	private String generateProjectPrefix() throws URISyntaxException {
	URI uri = new URI(webUrl);
	return uri.getHost() + (uri.getPort() == -1 ? "" : ":" + uri.getPort())
	+ uri.getPath();
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
	FilterChain chain) throws IOException, ServletException {
	if (request instanceof HttpServletRequest) {
	HttpServletRequest req = (HttpServletRequest) request;
	HttpServletResponse rsp = (HttpServletResponse) response;
	String servletPath = req.getServletPath();
	String goGet = req.getParameter("go-get");
	if ("1".equals(goGet)) {
	String projectName = getProjectName(servletPath);

	byte[] tosend = PAGE_404.getBytes();
	rsp.setStatus(404);
	if (projectExists(projectName)) {
	tosend = PAGE_200.replace("${content}", getContent(projectName))
	.getBytes();
	rsp.setStatus(200);
	}

	CacheHeaders.setNotCacheable(rsp);
	rsp.setContentType("text/html");
	rsp.setCharacterEncoding(HtmlDomUtil.ENC.name());
	rsp.setContentLength(tosend.length);
	try (OutputStream out = rsp.getOutputStream()) {
	out.write(tosend);
	}
	} else {
	chain.doFilter(request, response);
	}
	} else {
	chain.doFilter(request, response);
	}

	}

	private String getProjectName(String servletPath) {
	return servletPath.replaceFirst("/", "");
	}

	private CharSequence getContent(String projectName) {
	return projectPrefix + projectName + " git " + webUrl + "a/" + projectName;
	}

	private boolean projectExists(String projectName) {
	ProjectState p = projectCache.get(new Project.NameKey(projectName));
	return p != null;
	}
	}