/*
*
*
*java 自带工具类 分析
*
*
*/
package java.util;
public final class Objects {
private Objects() {
throw new AssertionError("No java.util.Objects instances for you!");
}
public static boolean equals(Object a, Object b) {
return (a == b) || (a != null && a.equals(b));
}
// 深度 对象相等比较
public static boolean deepEquals(Object a, Object b) {
if (a == b)
return true;
else if (a == null || b == null)
return false;
else
return Arrays.deepEquals0(a, b);
}
// hash码获取
public static int hashCode(Object o) {
return o != null ? o.hashCode() : 0;
}
// 数组的hashcode
public static int hash(Object... values) {
return Arrays.hashCode(values);
}
public static String toString(Object o) {
return String.valueOf(o);
}
// 带默认值的 toString 方法
public static String toString(Object o, String nullDefault) {
return (o != null) ? o.toString() : nullDefault;
}
// 自定义 比较
public static <T> int compare(T a, T b, Comparator<? super T> c) {
return (a == b) ? 0 : c.compare(a, b);
} // 不为空判断
public static <T> T requireNonNull(T obj) {
if (obj == null)
throw new NullPointerException();
return obj;
}
// 不空判断 带字符提示
public static <T> T requireNonNull(T obj, String message) {
if (obj == null)
throw new NullPointerException(message);
return obj;
} // 是否为空
public static boolean isNull(Object obj) {
return obj == null;
}
public static boolean nonNull(Object obj) {
return obj != null;
}
public static <T> T requireNonNull(T obj, Supplier<String> messageSupplier) {
if (obj == null)
throw new NullPointerException(messageSupplier.get());
return obj;
}
}