java/src/main/com/google/apphosting/utils/config/AppYamlProcessor.java

   1 // Copyright 2012 Google Inc. All Rights Reserved.
   2
   3 package com.google.apphosting.utils.config;
   4
   5 import java.io.File;
   6 import java.io.FileNotFoundException;
   7 import java.io.FileReader;
   8 import java.io.FileWriter;
   9 import java.io.IOException;
  10
  11 /**
  12  * A utility to convert an app.yaml file into a web.xml and an appengine-web.xml file
  13  *
  14  */
  15 public final class AppYamlProcessor {
  16
  17   /**
  18    * Reads the app.yaml file from the given directory and generates
  19    * a web.xml and an appengine-web.xml file in the same directory. Usually this directory
  20    * will be the WEB-INF directory of a WAR directory. If the directory
  21    * does not contain an app.yaml file, does nothing.
  22    * @param baseDir A directory possibly containing an app.yaml file
  23    * @param aewebPath The path to the appengine-web.xml file to generate.
  24    * @param webXmlPath The path to the web.xml file to generate.
  25    */
  26   public static void convert(File baseDir, String aewebPath, String webXmlPath) {
  27     File appYamlFile = new File(baseDir, "app.yaml");
  28     if (!appYamlFile.exists()) {
  29       return;
  30     }
  31     File aeweb = new File(aewebPath);
  32     File webXml = new File(webXmlPath);
  33     if (aeweb.exists() && webXml.exists() &&
  34         aeweb.lastModified() >= appYamlFile.lastModified() &&
  35         webXml.lastModified() >= appYamlFile.lastModified()) {
  36       return;
  37     }
  38     AppYaml appYaml;
  39     try {
  40       appYaml = AppYaml.parse(new FileReader(appYamlFile));
  41     } catch (FileNotFoundException ex) {
  42       throw new AppEngineConfigException("Unable to parse " + appYamlFile, ex);
  43     }
  44
  45     try {
  46       FileWriter aewebWriter = new FileWriter(aeweb);
  47       appYaml.generateAppEngineWebXml(aewebWriter);
  48       aewebWriter.close();
  49       aeweb.setLastModified(appYamlFile.lastModified());
  50     } catch (IOException ex) {
  51       throw new AppEngineConfigException("Unable to generate " + aeweb, ex);
  52     }
  53     try {
  54       FileWriter webXmlWriter = new FileWriter(webXml);
  55       appYaml.generateWebXml(webXmlWriter);
  56       webXmlWriter.close();
  57       webXml.setLastModified(appYamlFile.lastModified());
  58     } catch (IOException ex) {
  59       throw new AppEngineConfigException("Unable to generate " + webXml, ex);
  60     }
  61   }
  62
  63 }