參考jdk文件，可以看到如下注釋

Note that if the argument is equal to the value of Integer.MIN_VALUE, the most negative representable int value, the result is that same value, which is negative.

public class Test {

    public static void main(String[] args) {
        System.out.println(Integer.MIN_VALUE);
        System.out.println(Integer.MIN_VALUE < 0);
        System.out.println(Math.abs(Integer.MIN_VALUE));
        System.out.println(Math.abs(Integer.MIN_VALUE) < 0);
        System.out.println(Integer.MAX_VALUE + 1);
    }

}
 

結果如下

-2147483648
true
-2147483648
true
-2147483648