1 /* 2 * Copyright (C) 2006 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 android.os; 18 19 import java.util.ArrayList; 20 21 22 /** 23 * Gives access to the system properties store. The system properties 24 * store contains a list of string key-value pairs. 25 * 26 * {@hide} 27 */ 28 public class SystemProperties 29 { 30 public static final int PROP_NAME_MAX = 31; 31 public static final int PROP_VALUE_MAX = 91; 32 33 private static final ArrayList<Runnable> sChangeCallbacks = new ArrayList<Runnable>(); 34 35 private static native String native_get(String key); 36 private static native String native_get(String key, String def); 37 private static native int native_get_int(String key, int def); 38 private static native long native_get_long(String key, long def); 39 private static native boolean native_get_boolean(String key, boolean def); 40 private static native void native_set(String key, String def); 41 private static native void native_add_change_callback(); 42 43 /** 44 * Get the value for the given key. 45 * @return an empty string if the key isn't found 46 * @throws IllegalArgumentException if the key exceeds 32 characters 47 */ 48 public static String get(String key) { 49 if (key.length() > PROP_NAME_MAX) { 50 throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX); 51 } 52 return native_get(key); 53 } 54 55 /** 56 * Get the value for the given key. 57 * @return if the key isn't found, return def if it isn't null, or an empty string otherwise 58 * @throws IllegalArgumentException if the key exceeds 32 characters 59 */ 60 public static String get(String key, String def) { 61 if (key.length() > PROP_NAME_MAX) { 62 throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX); 63 } 64 return native_get(key, def); 65 } 66 67 /** 68 * Get the value for the given key, and return as an integer. 69 * @param key the key to lookup 70 * @param def a default value to return 71 * @return the key parsed as an integer, or def if the key isn't found or 72 * cannot be parsed 73 * @throws IllegalArgumentException if the key exceeds 32 characters 74 */ 75 public static int getInt(String key, int def) { 76 if (key.length() > PROP_NAME_MAX) { 77 throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX); 78 } 79 return native_get_int(key, def); 80 } 81 82 /** 83 * Get the value for the given key, and return as a long. 84 * @param key the key to lookup 85 * @param def a default value to return 86 * @return the key parsed as a long, or def if the key isn't found or 87 * cannot be parsed 88 * @throws IllegalArgumentException if the key exceeds 32 characters 89 */ 90 public static long getLong(String key, long def) { 91 if (key.length() > PROP_NAME_MAX) { 92 throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX); 93 } 94 return native_get_long(key, def); 95 } 96 97 /** 98 * Get the value for the given key, returned as a boolean. 99 * Values 'n', 'no', '0', 'false' or 'off' are considered false. 100 * Values 'y', 'yes', '1', 'true' or 'on' are considered true. 101 * (case sensitive). 102 * If the key does not exist, or has any other value, then the default 103 * result is returned. 104 * @param key the key to lookup 105 * @param def a default value to return 106 * @return the key parsed as a boolean, or def if the key isn't found or is 107 * not able to be parsed as a boolean. 108 * @throws IllegalArgumentException if the key exceeds 32 characters 109 */ 110 public static boolean getBoolean(String key, boolean def) { 111 if (key.length() > PROP_NAME_MAX) { 112 throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX); 113 } 114 return native_get_boolean(key, def); 115 } 116 117 /** 118 * Set the value for the given key. 119 * @throws IllegalArgumentException if the key exceeds 32 characters 120 * @throws IllegalArgumentException if the value exceeds 92 characters 121 */ 122 public static void set(String key, String val) { 123 if (key.length() > PROP_NAME_MAX) { 124 throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX); 125 } 126 if (val != null && val.length() > PROP_VALUE_MAX) { 127 throw new IllegalArgumentException("val.length > " + 128 PROP_VALUE_MAX); 129 } 130 native_set(key, val); 131 } 132 133 public static void addChangeCallback(Runnable callback) { 134 synchronized (sChangeCallbacks) { 135 if (sChangeCallbacks.size() == 0) { 136 native_add_change_callback(); 137 } 138 sChangeCallbacks.add(callback); 139 } 140 } 141 142 static void callChangeCallbacks() { 143 synchronized (sChangeCallbacks) { 144 //Log.i("foo", "Calling " + sChangeCallbacks.size() + " change callbacks!"); 145 if (sChangeCallbacks.size() == 0) { 146 return; 147 } 148 ArrayList<Runnable> callbacks = new ArrayList<Runnable>(sChangeCallbacks); 149 for (int i=0; i<callbacks.size(); i++) { 150 callbacks.get(i).run(); 151 } 152 } 153 } 154 } 155
