Java tutorial
/* * Copyright 2012 gitblit.com. * * 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.gitblit; import java.io.IOException; import java.text.MessageFormat; import java.text.ParseException; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.eclipse.jgit.lib.Repository; import org.eclipse.jgit.revwalk.RevCommit; import org.eclipse.jgit.revwalk.RevTree; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.gitblit.models.RefModel; import com.gitblit.utils.ArrayUtils; import com.gitblit.utils.JGitUtils; import com.gitblit.utils.MarkdownUtils; import com.gitblit.utils.StringUtils; /** * Serves the content of a gh-pages branch. * * @author James Moger * */ public class PagesServlet extends HttpServlet { private static final long serialVersionUID = 1L; private transient Logger logger = LoggerFactory.getLogger(PagesServlet.class); public PagesServlet() { super(); } /** * Returns an url to this servlet for the specified parameters. * * @param baseURL * @param repository * @param path * @return an url */ public static String asLink(String baseURL, String repository, String path) { if (baseURL.length() > 0 && baseURL.charAt(baseURL.length() - 1) == '/') { baseURL = baseURL.substring(0, baseURL.length() - 1); } return baseURL + Constants.PAGES + repository + "/" + (path == null ? "" : ("/" + path)); } /** * Retrieves the specified resource from the gh-pages branch of the * repository. * * @param request * @param response * @throws javax.servlet.ServletException * @throws java.io.IOException */ private void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String path = request.getPathInfo(); if (path.toLowerCase().endsWith(".git")) { // forward to url with trailing / // this is important for relative pages links response.sendRedirect(request.getServletPath() + path + "/"); return; } if (path.charAt(0) == '/') { // strip leading / path = path.substring(1); } // determine repository and resource from url String repository = ""; String resource = ""; Repository r = null; int offset = 0; while (r == null) { int slash = path.indexOf('/', offset); if (slash == -1) { repository = path; } else { repository = path.substring(0, slash); } r = GitBlit.self().getRepository(repository, false); offset = slash + 1; if (offset > 0) { resource = path.substring(offset); } if (repository.equals(path)) { // either only repository in url or no repository found break; } } ServletContext context = request.getSession().getServletContext(); try { if (r == null) { // repository not found! String mkd = MessageFormat .format("# Error\nSorry, no valid **repository** specified in this url: {0}!", repository); error(response, mkd); return; } // retrieve the content from the repository RefModel pages = JGitUtils.getPagesBranch(r); RevCommit commit = JGitUtils.getCommit(r, pages.getObjectId().getName()); if (commit == null) { // branch not found! String mkd = MessageFormat.format( "# Error\nSorry, the repository {0} does not have a **gh-pages** branch!", repository); error(response, mkd); r.close(); return; } response.setDateHeader("Last-Modified", JGitUtils.getCommitDate(commit).getTime()); String[] encodings = GitBlit.getEncodings(); RevTree tree = commit.getTree(); byte[] content = null; if (StringUtils.isEmpty(resource)) { // find resource String[] files = { "index.html", "index.htm", "index.mkd" }; for (String file : files) { content = JGitUtils.getStringContent(r, tree, file, encodings).getBytes(Constants.ENCODING); if (content != null) { resource = file; // assume text/html unless the servlet container // overrides response.setContentType("text/html; charset=" + Constants.ENCODING); break; } } } else { // specific resource try { String contentType = context.getMimeType(resource); if (contentType == null) { contentType = "text/plain"; } if (contentType.startsWith("text")) { content = JGitUtils.getStringContent(r, tree, resource, encodings) .getBytes(Constants.ENCODING); } else { content = JGitUtils.getByteContent(r, tree, resource); } response.setContentType(contentType); } catch (Exception e) { } } // no content, try custom 404 page if (ArrayUtils.isEmpty(content)) { String custom404 = JGitUtils.getStringContent(r, tree, "404.html", encodings); if (!StringUtils.isEmpty(custom404)) { content = custom404.getBytes(Constants.ENCODING); } // still no content if (ArrayUtils.isEmpty(content)) { String str = MessageFormat .format("# Error\nSorry, the requested resource **{0}** was not found.", resource); content = MarkdownUtils.transformMarkdown(str).getBytes(Constants.ENCODING); } try { // output the content logger.warn("Pages 404: " + resource); response.setStatus(HttpServletResponse.SC_NOT_FOUND); response.getOutputStream().write(content); response.flushBuffer(); } catch (Throwable t) { logger.error("Failed to write page to client", t); } return; } // check to see if we should transform markdown files for (String ext : GitBlit.getStrings(Keys.web.markdownExtensions)) { if (resource.endsWith(ext)) { String mkd = new String(content, Constants.ENCODING); content = MarkdownUtils.transformMarkdown(mkd).getBytes(Constants.ENCODING); break; } } try { // output the content response.getOutputStream().write(content); response.flushBuffer(); } catch (Throwable t) { logger.error("Failed to write page to client", t); } // close the repository r.close(); } catch (Throwable t) { logger.error("Failed to write page to client", t); } } private void error(HttpServletResponse response, String mkd) throws ServletException, IOException, ParseException { String content = MarkdownUtils.transformMarkdown(mkd); response.setContentType("text/html; charset=" + Constants.ENCODING); response.getWriter().write(content); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } }