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
17package android.os;
18
19
20/**
21 * Gives access to the system properties store.  The system properties
22 * store contains a list of string key-value pairs.
23 *
24 * {@hide}
25 */
26public class SystemProperties
27{
28    public static final int PROP_NAME_MAX = 31;
29    public static final int PROP_VALUE_MAX = 91;
30
31    private static native String native_get(String key);
32    private static native String native_get(String key, String def);
33    private static native int native_get_int(String key, int def);
34    private static native long native_get_long(String key, long def);
35    private static native boolean native_get_boolean(String key, boolean def);
36    private static native void native_set(String key, String def);
37
38    /**
39     * Get the value for the given key.
40     * @return an empty string if the key isn't found
41     * @throws IllegalArgumentException if the key exceeds 32 characters
42     */
43    public static String get(String key) {
44        if (key.length() > PROP_NAME_MAX) {
45            throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX);
46        }
47        return native_get(key);
48    }
49
50    /**
51     * Get the value for the given key.
52     * @return if the key isn't found, return def if it isn't null, or an empty string otherwise
53     * @throws IllegalArgumentException if the key exceeds 32 characters
54     */
55    public static String get(String key, String def) {
56        if (key.length() > PROP_NAME_MAX) {
57            throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX);
58        }
59        return native_get(key, def);
60    }
61
62    /**
63     * Get the value for the given key, and return as an integer.
64     * @param key the key to lookup
65     * @param def a default value to return
66     * @return the key parsed as an integer, or def if the key isn't found or
67     *         cannot be parsed
68     * @throws IllegalArgumentException if the key exceeds 32 characters
69     */
70    public static int getInt(String key, int def) {
71        if (key.length() > PROP_NAME_MAX) {
72            throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX);
73        }
74        return native_get_int(key, def);
75    }
76
77    /**
78     * Get the value for the given key, and return as a long.
79     * @param key the key to lookup
80     * @param def a default value to return
81     * @return the key parsed as a long, or def if the key isn't found or
82     *         cannot be parsed
83     * @throws IllegalArgumentException if the key exceeds 32 characters
84     */
85    public static long getLong(String key, long def) {
86        if (key.length() > PROP_NAME_MAX) {
87            throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX);
88        }
89        return native_get_long(key, def);
90    }
91
92    /**
93     * Get the value for the given key, returned as a boolean.
94     * Values 'n', 'no', '0', 'false' or 'off' are considered false.
95     * Values 'y', 'yes', '1', 'true' or 'on' are considered true.
96     * (case sensitive).
97     * If the key does not exist, or has any other value, then the default
98     * result is returned.
99     * @param key the key to lookup
100     * @param def a default value to return
101     * @return the key parsed as a boolean, or def if the key isn't found or is
102     *         not able to be parsed as a boolean.
103     * @throws IllegalArgumentException if the key exceeds 32 characters
104     */
105    public static boolean getBoolean(String key, boolean def) {
106        if (key.length() > PROP_NAME_MAX) {
107            throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX);
108        }
109        return native_get_boolean(key, def);
110    }
111
112    /**
113     * Set the value for the given key.
114     * @throws IllegalArgumentException if the key exceeds 32 characters
115     * @throws IllegalArgumentException if the value exceeds 92 characters
116     */
117    public static void set(String key, String val) {
118        if (key.length() > PROP_NAME_MAX) {
119            throw new IllegalArgumentException("key.length > " + PROP_NAME_MAX);
120        }
121        if (val != null && val.length() > PROP_VALUE_MAX) {
122            throw new IllegalArgumentException("val.length > " +
123                PROP_VALUE_MAX);
124        }
125        native_set(key, val);
126    }
127}
128