java.util.Objects

 

 

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{//对象判空     Integer integer = new Integer(1);     if (Objects.isNull(integer)) {         System.out.println("对象为空");     }     if (Objects.nonNull(integer)) {         System.out.println("对象不为空");     } }   {//对象为空抛异常     Integer integer1 = null;     integer1 = new Integer(128);     Objects.requireNonNull(integer1);     Objects.requireNonNull(integer1, "参数不能为空");     Objects.requireNonNull(integer1, () -> "参数不能为空"); }   {//判断两个对象是否相等     Integer integer1 = new Integer(1);     Integer integer2 = new Integer(1);     System.out.println(Objects.equals(integer1, integer2));       Long integer3 = new Long(1);     System.out.println(Objects.equals(integer1, integer3)); }   {//获取对象的hashCode     String str = new String("abc");     System.out.println(Objects.hashCode(str)); }