Annotation之四：注解中的-Xlint:unchecked和 -Xlint:deprecation

一、-Xlint:unchecked用法

对如下Test.java编译时

package com.dxz.annotation;
 
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Random;
 
public class Test {
    public static void main(String[] args) {
        ArrayList arr = new Test().getRandom(50);
        Iterator it = arr.iterator();
        while (it.hasNext()) {
            System.out.println(it.next());
        }
    }
 
    public ArrayList getRandom(int num) {
        ArrayList randomNum = new ArrayList();
        Random random = new Random();
        int temp = 0;
        for (int i = 0; i < num; i++) {
            temp = random.nextInt(num);
            int nums = temp + 1;
            if (randomNum.indexOf(new Integer(nums)) == -1) {
                randomNum.add(new Integer(nums));
            } else {
                i--;
            }
        }
        return randomNum;
    }
}

用javac编译

javac com/dxz/annotation/Test.java

结果：

增加参数-Xlint:unchecked

javac -Xlint:unchecked com/dxz/annotation/Test.java

结果：

二、-Xlint:deprecation