| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| ConfigServlet |
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| 1.9333333333333333;1.933 |
| 1 | /* | |
| 2 | * $Source: /usr/cvsroot/melati/melati/src/site/resources/withWebmacro/org.melati.servlet.ConfigServlet.html,v $ | |
| 3 | * $Revision: 1.1 $ | |
| 4 | * | |
| 5 | * Copyright (C) 2000 Tim Joyce | |
| 6 | * | |
| 7 | * Part of Melati (http://melati.org), a framework for the rapid | |
| 8 | * development of clean, maintainable web applications. | |
| 9 | * | |
| 10 | * Melati is free software; Permission is granted to copy, distribute | |
| 11 | * and/or modify this software under the terms either: | |
| 12 | * | |
| 13 | * a) the GNU General Public License as published by the Free Software | |
| 14 | * Foundation; either version 2 of the License, or (at your option) | |
| 15 | * any later version, | |
| 16 | * | |
| 17 | * or | |
| 18 | * | |
| 19 | * b) any version of the Melati Software License, as published | |
| 20 | * at http://melati.org | |
| 21 | * | |
| 22 | * You should have received a copy of the GNU General Public License and | |
| 23 | * the Melati Software License along with this program; | |
| 24 | * if not, write to the Free Software Foundation, Inc., | |
| 25 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the | |
| 26 | * GNU General Public License and visit http://melati.org to obtain the | |
| 27 | * Melati Software License. | |
| 28 | * | |
| 29 | * Feel free to contact the Developers of Melati (http://melati.org), | |
| 30 | * if you would like to work out a different arrangement than the options | |
| 31 | * outlined here. It is our intention to allow Melati to be used by as | |
| 32 | * wide an audience as possible. | |
| 33 | * | |
| 34 | * This program is distributed in the hope that it will be useful, | |
| 35 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 36 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 37 | * GNU General Public License for more details. | |
| 38 | * | |
| 39 | * Contact details for copyright holder: | |
| 40 | * | |
| 41 | * Tim Joyce <timj At paneris.org> | |
| 42 | * http://paneris.org/ | |
| 43 | * 68 Sandbanks Rd, Poole, Dorset. BH14 8BY. UK | |
| 44 | */ | |
| 45 | ||
| 46 | package org.melati.servlet; | |
| 47 | ||
| 48 | import java.io.PrintWriter; | |
| 49 | import java.io.IOException; | |
| 50 | ||
| 51 | import javax.servlet.ServletConfig; | |
| 52 | import javax.servlet.ServletException; | |
| 53 | import javax.servlet.http.HttpServlet; | |
| 54 | import javax.servlet.http.HttpServletRequest; | |
| 55 | import javax.servlet.http.HttpServletResponse; | |
| 56 | ||
| 57 | import org.melati.Melati; | |
| 58 | import org.melati.PoemContext; | |
| 59 | import org.melati.MelatiConfig; | |
| 60 | import org.melati.poem.AccessPoemException; | |
| 61 | import org.melati.poem.NoSuchRowPoemException; | |
| 62 | import org.melati.util.ConnectionPendingException; | |
| 63 | import org.melati.util.MelatiWriter; | |
| 64 | ||
| 65 | /** | |
| 66 | * Config Servlet is the simplest way to use Melati. | |
| 67 | * | |
| 68 | * All a ConfigServlet does is to configure a melati and combine the | |
| 69 | * doGet and doPost methods. Importantly it does not establish a poem session | |
| 70 | * leaving you to do this for yourself. | |
| 71 | * | |
| 72 | * If you want a poem session established, please extend PoemServlet. | |
| 73 | * | |
| 74 | * ConfigServlet does set up a basic PoemContext with the Method set, | |
| 75 | * but not the POEM logicaldatabase, table or troid. | |
| 76 | * | |
| 77 | * The URL is expected to take one of the following form: | |
| 78 | * | |
| 79 | * <BLOCKQUOTE><TT> | |
| 80 | * http://<I>h</I>/<I>s</I>/<I>meth</I> | |
| 81 | * </TT></BLOCKQUOTE> | |
| 82 | * | |
| 83 | * the method is broken out of the path info and passed to | |
| 84 | * your application code in the <TT>Melati</TT> and | |
| 85 | * <TT>PoemContext</TT> parameter | |
| 86 | * | |
| 87 | * <TABLE> | |
| 88 | * <TR> | |
| 89 | * <TD><TT><I>h</I></TT></TD> | |
| 90 | * <TD>host name, such as <TT>www.melati.org</TT></TD> | |
| 91 | * </TR> | |
| 92 | * <TR> | |
| 93 | * <TD><TT><I>s</I></TT></TD> | |
| 94 | * <TD> | |
| 95 | * servlet-determining part, such as | |
| 96 | * <TT>melati/org.melati.admin.Admin</TT> | |
| 97 | * </TD> | |
| 98 | * </TR> | |
| 99 | * <TR> | |
| 100 | * <TD><TT><I>meth</I></TT></TD> | |
| 101 | * <TD> | |
| 102 | * A freeform string telling your servlet what it is meant to do. This | |
| 103 | * is automatically made available in templates as | |
| 104 | * <TT>$melati.Method</TT>. | |
| 105 | * </TD> | |
| 106 | * </TR> | |
| 107 | * </TABLE> | |
| 108 | * | |
| 109 | * You can change the way these things are determined by overriding | |
| 110 | * <TT>poemContext(Melati)</TT>. | |
| 111 | */ | |
| 112 | ||
| 113 | 156 | public abstract class ConfigServlet extends HttpServlet { |
| 114 | ||
| 115 | /** | |
| 116 | * Eclipse generated. | |
| 117 | */ | |
| 118 | private static final long serialVersionUID = 8995954958766276122L; | |
| 119 | ||
| 120 | protected MelatiConfig melatiConfig; | |
| 121 | 78 | protected String sysAdminName = "nobody"; |
| 122 | 78 | protected String sysAdminEmail = "nobody@nobody.com";; |
| 123 | ||
| 124 | /** | |
| 125 | * Inititialise Melati. | |
| 126 | * | |
| 127 | * @param config a <code>ServletConfig</code> | |
| 128 | * @throws ServletException is anything goes wrong | |
| 129 | */ | |
| 130 | public void init(ServletConfig config) throws ServletException { | |
| 131 | 78 | super.init(config); |
| 132 | 78 | melatiConfig = melatiConfig(); |
| 133 | 76 | } |
| 134 | ||
| 135 | /** | |
| 136 | * Handles GET. | |
| 137 | * | |
| 138 | * @param request the incoming <code>HttpServletRequest</code> | |
| 139 | * @param response the outgoing <code>HttpServletResponse</code> | |
| 140 | */ | |
| 141 | public void doGet(HttpServletRequest request, | |
| 142 | HttpServletResponse response) { | |
| 143 | 1041 | doGetPostRequest(request, response); |
| 144 | 1039 | } |
| 145 | ||
| 146 | /** | |
| 147 | * Handle a POST. | |
| 148 | * | |
| 149 | * @param request the incoming <code>HttpServletRequest</code> | |
| 150 | * @param response the outgoing <code>HttpServletResponse</code> | |
| 151 | */ | |
| 152 | public void doPost(HttpServletRequest request, | |
| 153 | HttpServletResponse response) { | |
| 154 | 132 | doGetPostRequest(request, response); |
| 155 | 132 | } |
| 156 | ||
| 157 | /** | |
| 158 | * Process the request. | |
| 159 | * | |
| 160 | * Exceptions are presented to the user if practicable, or written to the log. | |
| 161 | * | |
| 162 | * @param request the incoming <code>HttpServletRequest</code> | |
| 163 | * @param response the outgoing <code>HttpServletResponse</code> | |
| 164 | */ | |
| 165 | private void doGetPostRequest(final HttpServletRequest request, | |
| 166 | final HttpServletResponse response) { | |
| 167 | 1173 | Melati melati = new Melati(melatiConfig, request, response); |
| 168 | try { | |
| 169 | 1173 | melati.establishCharsets(); |
| 170 | 1173 | melati.setPoemContext(poemContext(melati)); |
| 171 | 1173 | doConfiguredRequest(melati); |
| 172 | // send the output to the client | |
| 173 | 1147 | melati.write(); |
| 174 | } | |
| 175 | 28 | catch (Exception e) { |
| 176 | 28 | error(melati,e); |
| 177 | 1145 | } |
| 178 | 1171 | } |
| 179 | ||
| 180 | /** | |
| 181 | * Send an error message. | |
| 182 | * | |
| 183 | * @param melati the {@link Melati} | |
| 184 | * @param e the {@link Exception} to report | |
| 185 | */ | |
| 186 | public void error(Melati melati, Exception e) { | |
| 187 | 20 | melati.getResponse().setStatus(httpStatusCode(e)); |
| 188 | ||
| 189 | // has it been trapped already, if so, we don't need to relog it here | |
| 190 | 20 | if (! (e instanceof TrappedException)) { |
| 191 | try { | |
| 192 | // log it | |
| 193 | 16 | e.printStackTrace(System.err); |
| 194 | // and put it on the page | |
| 195 | 16 | melati.setResponseContentType ("text/html"); |
| 196 | 16 | MelatiWriter mw = melati.getWriter(); |
| 197 | // get rid of anything that has been written so far | |
| 198 | 16 | mw.reset(); |
| 199 | 16 | PrintWriter out = new PrintWriter(mw.getWriter()); |
| 200 | 16 | if (e instanceof ConnectionPendingException) { |
| 201 | 2 | writeConnectionPendingException(out,e); |
| 202 | } else { | |
| 203 | 14 | writeError(out,e); |
| 204 | } | |
| 205 | 16 | melati.write(); |
| 206 | 0 | } catch (IOException f) { |
| 207 | 0 | e.printStackTrace(System.err); |
| 208 | 0 | throw new TrappedException("Problem logging error", f); |
| 209 | 14 | } |
| 210 | } | |
| 211 | 18 | } |
| 212 | ||
| 213 | protected int httpStatusCode(Exception e) { | |
| 214 | 50 | if (e instanceof AccessPoemException) |
| 215 | 2 | return 401; // Not Authorized |
| 216 | 48 | if (e instanceof InvalidUsageException) |
| 217 | 2 | return 400; // Client error |
| 218 | 46 | if (e instanceof NoSuchRowPoemException) |
| 219 | 0 | return 404; // Not found |
| 220 | 46 | return 500; // Server error |
| 221 | } | |
| 222 | ||
| 223 | /** | |
| 224 | * Print an error directly to the client. | |
| 225 | * | |
| 226 | * This is rarely called, eg when the template engine | |
| 227 | * fails to render the default error template. | |
| 228 | * | |
| 229 | * @param out the <code>PrintWriter</code> to print to | |
| 230 | * @param e the {@link Exception} to report | |
| 231 | */ | |
| 232 | public void writeError(PrintWriter out, Exception e) { | |
| 233 | 14 | out.println("<html><head><title>Melati Error</title></head>"); |
| 234 | 14 | out.println("<!-- HTML generated in " + |
| 235 | "org.melati.servlet.ConfigServlet.java -->"); | |
| 236 | 14 | out.println("<body><h2>Melati Error</h2>"); |
| 237 | 14 | out.println("<h3>Reported from ConfigServlet</h3>"); |
| 238 | 14 | out.println("<p>An error has occured in the application"); |
| 239 | 14 | out.println("that runs this website, please contact <a href='mailto:"); |
| 240 | 14 | out.println(getSysAdminEmail() + "'>" + getSysAdminName() + "</a>"); |
| 241 | 14 | out.println(", with the information given below.</p>"); |
| 242 | 14 | out.println("<h4><font color='red'><pre>"); |
| 243 | 14 | e.printStackTrace(out); |
| 244 | 14 | out.println("</pre></font></h4></body></html>"); |
| 245 | 14 | } |
| 246 | ||
| 247 | /** | |
| 248 | * Print the <code>ConnectionPendingException</code> directly to the client. | |
| 249 | * | |
| 250 | * This is called if a request is made whilst the system is | |
| 251 | * still being initialised. | |
| 252 | * | |
| 253 | * @param out the <code>PrintWriter</code> to print to | |
| 254 | * @param e the {@link Exception} to report | |
| 255 | */ | |
| 256 | public void writeConnectionPendingException(PrintWriter out, Exception e) { | |
| 257 | 2 | out.println("<html><head><title>Database Initialising</title>\n"); |
| 258 | 2 | out.println("<META HTTP-EQUIV='Refresh' CONTENT='30'>\n</head>\n"); |
| 259 | 2 | out.println("<!-- Generated in org.melati.servlet.ConfigServlet.java -->"); |
| 260 | 2 | out.println("<body><center><h2>Database Initialising</h2><p> </p>"); |
| 261 | 2 | out.println("<p><b>Sorry</b>, "); |
| 262 | 2 | out.println("the database that runs this website is just starting up."); |
| 263 | 2 | out.println("This takes a few seconds, "); |
| 264 | 2 | out.println("so you should be able to use the site in a moment."); |
| 265 | 2 | out.println("<p>This page will refresh in 30 seconds, "); |
| 266 | 2 | out.println("and you will be able to continue.</p>"); |
| 267 | 2 | out.println("<!--"); |
| 268 | 2 | e.printStackTrace(out); |
| 269 | 2 | out.println("--></center></body></html>"); |
| 270 | 2 | } |
| 271 | ||
| 272 | /** | |
| 273 | * This method <b>SHOULD</b> be overidden. | |
| 274 | * @return the System Administrators name. | |
| 275 | */ | |
| 276 | public String getSysAdminName () { | |
| 277 | 8 | return sysAdminName; |
| 278 | } | |
| 279 | ||
| 280 | /** | |
| 281 | * This method <b>SHOULD</b> be overidden. | |
| 282 | * @return the System Administrators email address. | |
| 283 | */ | |
| 284 | public String getSysAdminEmail () { | |
| 285 | 8 | return sysAdminEmail; |
| 286 | } | |
| 287 | ||
| 288 | /** | |
| 289 | * @param sysAdminEmail The sysAdminEmail to set. | |
| 290 | */ | |
| 291 | protected void setSysAdminEmail(String sysAdminEmail) { | |
| 292 | 1121 | this.sysAdminEmail = sysAdminEmail; |
| 293 | 1121 | } |
| 294 | ||
| 295 | ||
| 296 | /** | |
| 297 | * @param sysAdminName The sysAdminName to set. | |
| 298 | */ | |
| 299 | protected void setSysAdminName(String sysAdminName) { | |
| 300 | 1121 | this.sysAdminName = sysAdminName; |
| 301 | 1121 | } |
| 302 | ||
| 303 | protected PoemContext poemContext(Melati melati) | |
| 304 | throws PathInfoException { | |
| 305 | 52 | PoemContext it = new PoemContext(); |
| 306 | 52 | String[] parts = melati.getPathInfoParts(); |
| 307 | 52 | if (parts.length > 0) |
| 308 | 32 | it.setMethod(parts[parts.length - 1]); |
| 309 | 52 | return it; |
| 310 | } | |
| 311 | ||
| 312 | /** | |
| 313 | * To override any setting from org.melati.MelatiConfig.properties, | |
| 314 | * simply override this method and return a valid MelatiConfig. | |
| 315 | * | |
| 316 | * eg to use a different AccessHandler from the default: | |
| 317 | * | |
| 318 | * <PRE> | |
| 319 | * protected MelatiConfig melatiConfig() throws MelatiException { | |
| 320 | * MelatiConfig config = super.melatiConfig(); | |
| 321 | * config.setAccessHandler(new YourAccessHandler()); | |
| 322 | * return config; | |
| 323 | * } | |
| 324 | * </PRE> | |
| 325 | * | |
| 326 | * @return a new {@link MelatiConfig} | |
| 327 | */ | |
| 328 | protected MelatiConfig melatiConfig() { | |
| 329 | 74 | MelatiConfig m = new MelatiConfig(); |
| 330 | 74 | String realPath = getServletConfig().getServletContext().getRealPath("/"); |
| 331 | 74 | if (realPath == null) |
| 332 | 0 | throw new NullPointerException(); |
| 333 | 74 | m.setRealPath(realPath); |
| 334 | 74 | return m; |
| 335 | } | |
| 336 | ||
| 337 | /** | |
| 338 | * Instantiate this method to build up your own output. | |
| 339 | * @param melati | |
| 340 | * @throws Exception if anything goes wrong | |
| 341 | */ | |
| 342 | protected abstract void doConfiguredRequest(Melati melati) | |
| 343 | throws Exception; | |
| 344 | ||
| 345 | ||
| 346 | } |