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