libcore.util.Objects Maven / Gradle / Ivy
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package libcore.util;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Arrays;
public final class Objects {
private Objects() {}
/**
* Returns true if two possibly-null objects are equal.
*/
public static boolean equal(Object a, Object b) {
return a == b || (a != null && a.equals(b));
}
public static int hashCode(Object o) {
return (o == null) ? 0 : o.hashCode();
}
/**
* Returns a string reporting the value of each declared field, via reflection.
* Static and transient fields are automatically skipped. Produces output like
* "SimpleClassName[integer=1234,string="hello",character='c',intArray=[1,2,3]]".
*/
public static String toString(Object o) {
Class c = o.getClass();
StringBuilder sb = new StringBuilder();
sb.append(c.getSimpleName()).append('[');
int i = 0;
for (Field f : c.getDeclaredFields()) {
if ((f.getModifiers() & (Modifier.STATIC | Modifier.TRANSIENT)) != 0) {
continue;
}
f.setAccessible(true);
try {
Object value = f.get(o);
if (i++ > 0) {
sb.append(',');
}
sb.append(f.getName());
sb.append('=');
if (value.getClass().isArray()) {
if (value.getClass() == boolean[].class) {
sb.append(Arrays.toString((boolean[]) value));
} else if (value.getClass() == byte[].class) {
sb.append(Arrays.toString((byte[]) value));
} else if (value.getClass() == char[].class) {
sb.append(Arrays.toString((char[]) value));
} else if (value.getClass() == double[].class) {
sb.append(Arrays.toString((double[]) value));
} else if (value.getClass() == float[].class) {
sb.append(Arrays.toString((float[]) value));
} else if (value.getClass() == int[].class) {
sb.append(Arrays.toString((int[]) value));
} else if (value.getClass() == long[].class) {
sb.append(Arrays.toString((long[]) value));
} else if (value.getClass() == short[].class) {
sb.append(Arrays.toString((short[]) value));
} else {
sb.append(Arrays.toString((Object[]) value));
}
} else if (value.getClass() == Character.class) {
sb.append('\'').append(value).append('\'');
} else if (value.getClass() == String.class) {
sb.append('"').append(value).append('"');
} else {
sb.append(value);
}
} catch (IllegalAccessException unexpected) {
throw new AssertionError(unexpected);
}
}
sb.append("]");
return sb.toString();
}
}