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      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.prefs;
     18 
     19 import java.io.File;
     20 
     21 /**
     22  * Manages the location of the android files (including emulator files, ddms config, debug keystore)
     23  */
     24 public final class AndroidLocation {
     25     /**
     26      * Virtual Device folder inside the path returned by {@link #getFolder()}
     27      */
     28     public static final String FOLDER_AVD = "avd";
     29 
     30     /**
     31      * Throw when the location of the android folder couldn't be found.
     32      */
     33     public static final class AndroidLocationException extends Exception {
     34         private static final long serialVersionUID = 1L;
     35 
     36         public AndroidLocationException(String string) {
     37             super(string);
     38         }
     39     }
     40 
     41     private static String sPrefsLocation = null;
     42 
     43     /**
     44      * Returns the folder used to store android related files.
     45      * @return an OS specific path, terminated by a separator.
     46      * @throws AndroidLocationException
     47      */
     48     public final static String getFolder() throws AndroidLocationException {
     49         if (sPrefsLocation == null) {
     50             String home = findValidPath("ANDROID_SDK_HOME", "user.home", "HOME");
     51 
     52             // if the above failed, we throw an exception.
     53             if (home == null) {
     54                 throw new AndroidLocationException(
     55                         "Unable to get the Android SDK home directory.\n" +
     56                         "Make sure the environment variable ANDROID_SDK_HOME is set up.");
     57             } else {
     58                 sPrefsLocation = home + File.separator + ".android" + File.separator;
     59             }
     60         }
     61 
     62         // make sure the folder exists!
     63         File f = new File(sPrefsLocation);
     64         if (f.exists() == false) {
     65             try {
     66                 f.mkdir();
     67             } catch (SecurityException e) {
     68                 AndroidLocationException e2 = new AndroidLocationException(String.format(
     69                         "Unable to create folder '%1$s'. " +
     70                         "This is the path of preference folder expected by the Android tools.",
     71                         sPrefsLocation));
     72                 e2.initCause(e);
     73                 throw e2;
     74             }
     75         } else if (f.isFile()) {
     76             throw new AndroidLocationException(sPrefsLocation +
     77                     " is not a directory! " +
     78                     "This is the path of preference folder expected by the Android tools.");
     79         }
     80 
     81         return sPrefsLocation;
     82     }
     83 
     84     /**
     85      * Checks a list of system properties and/or system environment variables for validity, and
     86      * existing director, and returns the first one.
     87      * @param names
     88      * @return the content of the first property/variable.
     89      */
     90     private static String findValidPath(String... names) {
     91         for (String name : names) {
     92             String path;
     93             if (name.indexOf('.') != -1) {
     94                 path = System.getProperty(name);
     95             } else {
     96                 path = System.getenv(name);
     97             }
     98 
     99             if (path != null) {
    100                 File f = new File(path);
    101                 if (f.isDirectory()) {
    102                     return path;
    103                 }
    104             }
    105         }
    106 
    107         return null;
    108     }
    109 }
    110