1/*
2 * Copyright (C) 2010 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 libcore.util;
18
19import java.lang.reflect.Field;
20import java.lang.reflect.Modifier;
21import java.util.Arrays;
22
23public final class Objects {
24    private Objects() {}
25
26    /**
27     * Returns true if two possibly-null objects are equal.
28     */
29    public static boolean equal(Object a, Object b) {
30        return a == b || (a != null && a.equals(b));
31    }
32
33    public static int hashCode(Object o) {
34        return (o == null) ? 0 : o.hashCode();
35    }
36
37    /**
38     * Returns a string reporting the value of each declared field, via reflection.
39     * Static and transient fields are automatically skipped. Produces output like
40     * "SimpleClassName[integer=1234,string="hello",character='c',intArray=[1,2,3]]".
41     */
42    public static String toString(Object o) {
43        Class<?> c = o.getClass();
44        StringBuilder sb = new StringBuilder();
45        sb.append(c.getSimpleName()).append('[');
46        int i = 0;
47        for (Field f : c.getDeclaredFields()) {
48            if ((f.getModifiers() & (Modifier.STATIC | Modifier.TRANSIENT)) != 0) {
49                continue;
50            }
51            f.setAccessible(true);
52            try {
53                Object value = f.get(o);
54
55                if (i++ > 0) {
56                    sb.append(',');
57                }
58
59                sb.append(f.getName());
60                sb.append('=');
61
62                if (value.getClass().isArray()) {
63                    if (value.getClass() == boolean[].class) {
64                        sb.append(Arrays.toString((boolean[]) value));
65                    } else if (value.getClass() == byte[].class) {
66                        sb.append(Arrays.toString((byte[]) value));
67                    } else if (value.getClass() == char[].class) {
68                        sb.append(Arrays.toString((char[]) value));
69                    } else if (value.getClass() == double[].class) {
70                        sb.append(Arrays.toString((double[]) value));
71                    } else if (value.getClass() == float[].class) {
72                        sb.append(Arrays.toString((float[]) value));
73                    } else if (value.getClass() == int[].class) {
74                        sb.append(Arrays.toString((int[]) value));
75                    } else if (value.getClass() == long[].class) {
76                        sb.append(Arrays.toString((long[]) value));
77                    } else if (value.getClass() == short[].class) {
78                        sb.append(Arrays.toString((short[]) value));
79                    } else {
80                        sb.append(Arrays.toString((Object[]) value));
81                    }
82                } else if (value.getClass() == Character.class) {
83                    sb.append('\'').append(value).append('\'');
84                } else if (value.getClass() == String.class) {
85                    sb.append('"').append(value).append('"');
86                } else {
87                    sb.append(value);
88                }
89            } catch (IllegalAccessException unexpected) {
90                throw new AssertionError(unexpected);
91            }
92        }
93        sb.append("]");
94        return sb.toString();
95    }
96}
97