Hutool-Core核心（九）

    /**
     * RandomUtil使用
     */
    public static void test1() {
        //RandomUtil.randomInt
        int randomInt = RandomUtil.randomInt();
        System.out.println("test1--randomInt==>"+randomInt);
        //最大
        int randomInt1 = RandomUtil.randomInt(100);
        System.out.println("test1--randomInt1==>"+randomInt1);
        //最大最小
        int randomInt2 = RandomUtil.randomInt(10, 100);
        System.out.println("test1--randomInt2==>"+randomInt2);

        //RandomUtil.randomInts 随机排列[0,10)
        int[] ints = RandomUtil.randomInts(10);
        System.out.println("test1--ints==>"+Arrays.toString(ints));

        //RandomUtil.randomBytes 随机 bytes，一般用于密码或者 salt 生成
        byte[] bytes = RandomUtil.randomBytes(10);
        System.out.println("test1--bytes==>"+Arrays.toString(bytes));

        //RandomUtil.randomEle 随机获得列表中的元素
        String randomEle = RandomUtil.randomEle(new String[]{"a", "b", "c"});
        System.out.println("test1--randomEle==>"+randomEle);

        //RandomUtil.randomEleSet 随机获得列表中的一定量的不重复元素，返回 LinkedHashSet
        Set<Integer> set = RandomUtil.randomEleSet(
                CollUtil.newArrayList(1,1,2,2,3,3,4,4,5,5,6,6,6,6,6,6,6),2);
        System.out.println("test1--set==>"+set);

        //RandomUtil.randomNumbers 获得一个只包含数字的字符串
        String randomNumbers = RandomUtil.randomNumbers(10);
        System.out.println("test1--randomNumbers==>"+randomNumbers);

        //RandomUtil.weightRandom 权重随机生成器，传入带权重的对象，
        //然后根据权重随机获取对象(权重只是概率比较大，不是百分百)
        WeightRandom.WeightObj<String>[] weightObjs = new WeightRandom.WeightObj[3];
        weightObjs[0] = new WeightRandom.WeightObj<>("A", 10);
        weightObjs[1] = new WeightRandom.WeightObj<>("B", 30);
        weightObjs[2] = new WeightRandom.WeightObj<>("C", 60);
        // 根据权重随机获取一个对象
        WeightRandom<String> stringWeightRandom = RandomUtil.weightRandom(weightObjs);

        // 输出结果
        System.out.println("随机获取的对象是: " + stringWeightRandom.next());
    }

//生成的UUID是带-的字符串，类似于：a5c8a5e8-df2b-4706-bea4-08d0939410e3
String uuid = IdUtil.randomUUID();

//生成的是不带-的字符串，类似于：b17f24ff026d40949c85a24f4f375d42
String simpleUUID = IdUtil.simpleUUID();

    /**
     * 1.UUID
     */
    public static void test1() {
        //生成的UUID是带-的字符串，类似于：a5c8a5e8-df2b-4706-bea4-08d0939410e3
        String uuid = IdUtil.randomUUID();
        System.out.println("test1--uuid==>"+uuid);

        //生成的是不带-的字符串，类似于：b17f24ff026d40949c85a24f4f375d42
        String simpleUUID = IdUtil.simpleUUID();
        System.out.println("test1--simpleUUID==>"+simpleUUID);

        String fastSimpleUUID = IdUtil.fastSimpleUUID();
        System.out.println("test1--fastSimpleUUID==>"+fastSimpleUUID);
        String fastUUID = IdUtil.fastUUID();
        System.out.println("test1--fastUUID==>"+fastUUID);

        //结果：
        //test1--uuid==>4873489f-e80c-4a44-8c21-c5fc34c264f2
        //test1--simpleUUID==>876ed5dc11d044aebb0547a3321ed298
        //test1--fastSimpleUUID==>caea9cc54e914790b7b438c505cd7b78
        //test1--fastUUID==>7864d747-3579-44e4-a4b9-53cf85afcbb9
    }

//生成类似：5b9e306a4df4f8c54a39fb0c
String id = ObjectId.next();

//方法2：从Hutool-4.1.14开始提供
String id2 = IdUtil.objectId();

    /**
     * 2.ObjectId
     */
    public static void test2() {
        String objectId = IdUtil.objectId();
        System.out.println("test2--objectId==>"+objectId);

        //生成类似：5b9e306a4df4f8c54a39fb0c
        String id = ObjectId.next();
        System.out.println("test2--id==>"+id);

        //方法2：从Hutool-4.1.14开始提供
        String id2 = IdUtil.objectId();
        System.out.println("test2--id2==>"+id2);

        //结果：
        //test2--objectId==>677f468a502e7e99744a5a9c
        //test2--id==>677f468a502e7e99744a5a9d
        //test2--id2==>677f468a502e7e99744a5a9e
    }

//参数1为终端ID
//参数2为数据中心ID
Snowflake snowflake = IdUtil.getSnowflake(1, 1);
long id = snowflake.nextId();

//简单使用
long id = IdUtil.getSnowflakeNextId();
String id = IdUtil.getSnowflakeNextIdStr();

    /**
     * 3.Snowflake
     */
    public static void test3() {
        //参数1为终端ID
        //参数2为数据中心ID
        Snowflake snowflake = IdUtil.getSnowflake(1, 1);
        long id = snowflake.nextId();
        System.out.println("test3--id==>"+id);

        //简单使用
        long id1 = IdUtil.getSnowflakeNextId();
        String id2 = IdUtil.getSnowflakeNextIdStr();
        System.out.println("test3--id1==>"+id1);
        System.out.println("test3--id2==>"+id2);

        //结果：
        //test3--id==>1877200198204264448
        //test3--id1==>1877200198425829376
        //test3--id2==>1877200198425829377
    }

    /**
     * 1.创建不同类型的引用对象
     */
    private static void test1() {
        String strongReference = new String("Strong Reference");

        // 创建软引用
        Reference<String> softReference = ReferenceUtil.create(ReferenceUtil.ReferenceType.SOFT, strongReference);
        System.out.println("软引用内容: " + softReference.get());

        // 创建弱引用
        Reference<String> weakReference = ReferenceUtil.create(ReferenceUtil.ReferenceType.WEAK, strongReference);
        System.out.println("弱引用内容: " + weakReference.get());

        // 创建虚引用
        ReferenceQueue<String> queue = new ReferenceQueue<>();
        Reference<String> phantomReference = ReferenceUtil.create(ReferenceUtil.ReferenceType.PHANTOM, strongReference, queue);
        System.out.println("虚引用内容: " + phantomReference.get());
        
        //结果：
        //软引用内容: Strong Reference
        //弱引用内容: Strong Reference
        //虚引用内容: null
    }