From ffa1d4435ba8efbd4a60f1677ba2277ed7be9251 Mon Sep 17 00:00:00 2001 From: kyriewhluo Date: Fri, 23 Aug 2024 18:26:39 +0800 Subject: [PATCH] =?UTF-8?q?=E4=BB=A3=E7=A0=81=E4=BF=AE=E8=AE=A2=E4=B8=8E?= =?UTF-8?q?=E5=8A=9F=E8=83=BD=E6=9B=B4=E6=96=B0=EF=BC=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit - 新增策略模式示例：在设计模式包中引入策略模式（StrategyPattern），实现支付策略的灵活选择与执行。 - 单例模式示例更新：优化购物车示例，引入线程安全的单例模式实现，并调整类定义与实例化过程。 - 处理线程池执行异常：在ThreadDemo1中处理线程池执行时的异常情况，确保任务异常（如除零错误）时程序的稳定运行。 - 另外，修正了一些代码中的笔误并进行了格式化处理，以保持代码的清晰与规范。 --- .../designPattern/SingletonPattern.java | 171 ++++++++++++------ .../designPattern/StrategyPattern.java | 66 +++++++ .../leetCode/LinkedList/LeetCode234.java | 105 +++++++++++ .../java/cn/whaifree/test/ThreadDemo1.java | 136 +++++++++++++- 4 files changed, 423 insertions(+), 55 deletions(-) create mode 100644 src/main/java/cn/whaifree/designPattern/StrategyPattern.java create mode 100644 src/main/java/cn/whaifree/leetCode/LinkedList/LeetCode234.java diff --git a/src/main/java/cn/whaifree/designPattern/SingletonPattern.java b/src/main/java/cn/whaifree/designPattern/SingletonPattern.java index 22bf363..745adee 100644 --- a/src/main/java/cn/whaifree/designPattern/SingletonPattern.java +++ b/src/main/java/cn/whaifree/designPattern/SingletonPattern.java @@ -1,64 +1,16 @@ package cn.whaifree.designPattern; +import java.util.ArrayList; import java.util.HashMap; import java.util.Scanner; import java.util.function.BiConsumer; public class SingletonPattern { - /** - * https://kamacoder.com/problempage.php?pid=1074 - * - * 【设计模式专题之单例模式】1.小明的购物车 - * 题目描述 - * 小明去了一家大型商场，拿到了一个购物车，并开始购物。请你设计一个购物车管理器，记录商品添加到购物车的信息（商品名称和购买数量），并在购买结束后打印出商品清单。（在整个购物过程中，小明只有一个购物车实例存在）。 - * 输入描述 - * 输入包含若干行，每行包含两部分信息，分别是商品名称和购买数量。商品名称和购买数量之间用空格隔开。 - * 输出描述 - * 输出包含小明购物车中的所有商品及其购买数量。每行输出一种商品的信息，格式为 "商品名称 购买数量"。 - * 输入示例 - * Apple 3 - * Banana 2 - * Orange 5 - * 输出示例 - * Apple 3 - * Banana 2 - * Orange 5 - * 提示信息 - * 本道题目请使用单例设计模式： - * - * 使用私有静态变量来保存购物车实例。 - * - * 使用私有构造函数防止外部直接实例化。 - */ +} - static class ManagerCar{ - - private HashMap carHas = null; - - public ManagerCar() { - this.carHas = new HashMap<>(); - } - - public HashMap getCarHas() { - return carHas; - } - - private volatile static ManagerCar managerCar; - - public static ManagerCar getManagerCar() { - if (managerCar == null) { - synchronized (ManagerCar.class) { - if (managerCar == null) { - managerCar = new ManagerCar(); - } - } - } - return managerCar; - } - - } +class Main{ public static void main(String[] args) { Scanner scanner = new Scanner(System.in); HashMap carHas = ManagerCar.getManagerCar().getCarHas(); @@ -66,7 +18,7 @@ public class SingletonPattern { while (true) { String nextLine = scanner.nextLine(); - if ("stop".equals(nextLine)) { + if ("exit".equals(nextLine)) { break; } String[] s = nextLine.split(" "); @@ -88,6 +40,121 @@ public class SingletonPattern { scanner.close(); } +} +/** + * https://kamacoder.com/problempage.php?pid=1074 + * + * 【设计模式专题之单例模式】1.小明的购物车 + * 题目描述 + * 小明去了一家大型商场，拿到了一个购物车，并开始购物。请你设计一个购物车管理器，记录商品添加到购物车的信息（商品名称和购买数量），并在购买结束后打印出商品清单。（在整个购物过程中，小明只有一个购物车实例存在）。 + * 输入描述 + * 输入包含若干行，每行包含两部分信息，分别是商品名称和购买数量。商品名称和购买数量之间用空格隔开。 + * 输出描述 + * 输出包含小明购物车中的所有商品及其购买数量。每行输出一种商品的信息，格式为 "商品名称 购买数量"。 + * 输入示例 + * Apple 3 + * Banana 2 + * Orange 5 + * 输出示例 + * Apple 3 + * Banana 2 + * Orange 5 + * 提示信息 + * 本道题目请使用单例设计模式： + * + * 使用私有静态变量来保存购物车实例。 + * + * 使用私有构造函数防止外部直接实例化。 + */ + +class ManagerCar{ + + public HashMap carHas = null; + + public ManagerCar() { + this.carHas = new HashMap<>(); + } + + public HashMap getCarHas() { + return carHas; + } + + private volatile static ManagerCar managerCar; + + public static ManagerCar getManagerCar() { + if (managerCar == null) { + synchronized (ManagerCar.class) { + if (managerCar == null) { + managerCar = new ManagerCar(); + } + } + } + return managerCar; + } } + + + +class ShoppingCart { + + private static ShoppingCart instance = null; + private static ArrayList productNames = new ArrayList<>(); + private static ArrayList productQuantities = new ArrayList<>(); + + private ShoppingCart() { + + } + + public static ShoppingCart getInstance() { + if (instance == null) { + synchronized (ManagerCar.class) { + if (instance == null) { + instance = new ShoppingCart(); + } + } + } + return instance; + } + + public void Add(String name, int quantity) { + productNames.add(name); + productQuantities.add(quantity); + System.out.println(name + " " + quantity); + } +} + +class Main1 { + public static void main(String[] args) { + ShoppingCart cart = ShoppingCart.getInstance(); + Scanner scanner = new Scanner(System.in); + + String inputLine; + while (scanner.hasNextLine()) { + inputLine = scanner.nextLine(); + + if ("exit".equalsIgnoreCase(inputLine)) { + break; + } + + String[] parts = inputLine.split(" "); + + if (parts.length == 2) { + String name = parts[0]; + int quantity; + + try { + quantity = Integer.parseInt(parts[1]); + cart.Add(name, quantity); + } catch (NumberFormatException e) { + System.out.println("输入错误，请重新输入"); + } + } else { + System.out.println("输入错误，请重新输入"); + } + } + + scanner.close(); + } +} diff --git a/src/main/java/cn/whaifree/designPattern/StrategyPattern.java b/src/main/java/cn/whaifree/designPattern/StrategyPattern.java new file mode 100644 index 0000000..42b4c27 --- /dev/null +++ b/src/main/java/cn/whaifree/designPattern/StrategyPattern.java @@ -0,0 +1,66 @@ +package cn.whaifree.designPattern; + +public class StrategyPattern { + + enum PayType{ + ALI(1, "阿里", new AliPayStrategy()), + WX(2,"微信", new WxPayStrategy()); + + int code; + String name; + PayStrategy payStrategy; + + PayType(int code, String name, PayStrategy payStrategy) { + this.code = code; + this.name = name; + this.payStrategy = payStrategy; + } + + public static PayStrategy getPayStrategy(Integer code) { + for (PayType value : values()) { + if (value.code == code) { + return value.payStrategy; + } + } + return null; + } + } + + interface PayStrategy { + + boolean pay(); + } + + static class AliPayStrategy implements PayStrategy { + + @Override + public boolean pay() { + System.out.println("ali"); + return false; + } + } + + static class WxPayStrategy implements PayStrategy { + + @Override + public boolean pay() { + System.out.println("wx"); + return false; + } + } + + + static class PayService { + public void pay(Integer code) { + PayStrategy payStrategy = PayType.getPayStrategy(code); + if (payStrategy != null) { + payStrategy.pay(); + } + } + } + + + public static void main(String[] args) { + new PayService().pay(2); + } +} diff --git a/src/main/java/cn/whaifree/leetCode/LinkedList/LeetCode234.java b/src/main/java/cn/whaifree/leetCode/LinkedList/LeetCode234.java new file mode 100644 index 0000000..1284a5a --- /dev/null +++ b/src/main/java/cn/whaifree/leetCode/LinkedList/LeetCode234.java @@ -0,0 +1,105 @@ +package cn.whaifree.leetCode.LinkedList; + +import cn.whaifree.leetCode.model.ListNode; +import org.junit.Test; + +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.CountDownLatch; +import java.util.function.BiConsumer; + +public class LeetCode234 { + + + public static void main(String[] args) throws InterruptedException { + ConcurrentHashMap map = new ConcurrentHashMap<>(); + for (int i = 0; i < 10; i++) { + map.put("1", 1); + } + + CountDownLatch countDownLatch = new CountDownLatch(10); + + new Thread(new Runnable() { + @Override + public void run() { + map.forEach( + new BiConsumer() { + @Override + public void accept(String s, Integer integer) { + System.out.println(s + ":" + integer); + } + } + ); + } + }).start(); + + new Thread(new Runnable() { + @Override + public void run() { + for (int i = 0; i < 10; i++) { + map.put("i" + i, i); + countDownLatch.countDown(); + } + } + }).start(); + + countDownLatch.await(); + System.out.println(map.size()); + } + + + @Test + public void test() + { + ListNode listNode = ListNode.listNodeFromArray(new int[]{1, 3, 3,2, 1}); + System.out.println(new Solution().isPalindrome(listNode)); + } + /** + * 1. 截取一半 + * - 逆转、对比 + * 2. 输出到list中，再回问判断 + * 3. + */ + + class Solution { + public boolean isPalindrome(ListNode head) { + int len = 0; + ListNode index = head; + while (index != null) { + len++; + index = index.next; + } + + index = head; + for (int i = 0; i < len / 2; i++) { + index = index.next; + } + + ListNode newHead = reverseList(index); + + + ListNode A = head; + ListNode B = newHead; + while (B != null) { + if (A.val != B.val) { + return false; + } + A = A.next; + B = B.next; + } + return true; + } + + private ListNode reverseList(ListNode head) { + ListNode prev = null; + ListNode curr = head; + while (curr != null) { + ListNode nextTemp = curr.next; + curr.next = prev; + prev = curr; + curr = nextTemp; + } + return prev; + } + + } +} diff --git a/src/main/java/cn/whaifree/test/ThreadDemo1.java b/src/main/java/cn/whaifree/test/ThreadDemo1.java index f864e29..f7bdacd 100644 --- a/src/main/java/cn/whaifree/test/ThreadDemo1.java +++ b/src/main/java/cn/whaifree/test/ThreadDemo1.java @@ -1,7 +1,7 @@ package cn.whaifree.test; -import java.util.ArrayList; -import java.util.List; +import java.lang.reflect.Proxy; +import java.util.*; import java.util.concurrent.*; import java.util.concurrent.atomic.AtomicInteger; @@ -72,7 +72,7 @@ public class ThreadDemo1 { static class CyclicBarrierDemo2{ public static void main(String[] args) throws InterruptedException { - +// Proxy.newProxyInstance() // 每9个cyclicBarrier.await()执行后，都执行一次wait CyclicBarrier cyclicBarrier = new CyclicBarrier(9, () -> System.out.println("上面的9个执行完了,轮到我了 wait complete！") // 等待前9次执行结束 @@ -116,4 +116,134 @@ public class ThreadDemo1 { executorService.shutdown(); } } + + + } + +class p2{ + + public static void main(String[] args) { + ExecutorService executorService = Executors.newCachedThreadPool(); + List> ar = new ArrayList<>(); + + for (int i = 0; i < 10; i++) { + int finalI = i; + Future submit = executorService.submit(new Callable() { + @Override + public Boolean call() throws Exception { + if (finalI == 3) { + throw new MyException(); + } + return true; + } + }); + ar.add(submit); + } + + + try { + for (Future submit : ar) { + submit.get(); + } + } catch (InterruptedException e) { + throw new RuntimeException(e); + } catch (ExecutionException e) { + if (e.getCause() instanceof MyException){ + System.out.println("我捕获到了"); + } + } + System.out.println("1"); + + + try { + for (int count = 1; count <= 5; count++) { + if (count == 3) { + //故意制造一下异常 + int num = 1 / 0; + } else { + System.out.println("count:" + count + " 业务正常执行"); + } + } + } catch (Exception e) { + System.out.println("try catch 在for 外面的情形， 出现了异常，for循环显然被中断"); + } + + for (int count = 1; count <= 5; count++) { + try { + if (count == 3) { + //故意制造一下异常 + int num = 1 / 0; + } else { + System.out.println("count:" + count + " 业务正常执行"); + } + } catch (Exception e) { + System.out.println("try catch 在for 里面的情形， 出现了异常，for循环显然继续执行"); + } + } + + + + + } +} + + +class MyException extends RuntimeException { + + + private static ThreadPoolExecutor resetInstanceExecutor = new ThreadPoolExecutor(10, 10, 0L, TimeUnit.MILLISECONDS, + new LinkedBlockingQueue(), new ThreadPoolExecutor.CallerRunsPolicy()); + + + public static void main(String[] args) { + + + List instance = Arrays.asList("i-12345678", "i-23456789", "i-34567890", "i-45678901", "i-56789012", + "i-67890123", "i-78901234", "i-89012345", "i-90123456", "i-101234567"); + CountDownLatch countDownLatch = new CountDownLatch(10); + + Long startTimestamp = System.currentTimeMillis(); + + Map> resetInstanceMap = new HashMap<>(); + boolean exceedRateLimit = false; // 没有被限频 + for (String instanceId : instance) { + Future result = resetInstanceExecutor.submit(new ResetInstanceCallable(instanceId,countDownLatch)); + resetInstanceMap.put(instanceId, result); + } + + for (Map.Entry> futureEntry : resetInstanceMap.entrySet()) { + try { + futureEntry.getValue().get(); + } + catch (MyException ex){ + System.out.println("my exception"); // Callable内抛出的自定义异常无法被捕获，Callable内抛出的自定义异常无法被捕获 + // get()方法会抛出一个ExecutionException，而这个异常的cause才是原始的异常 + exceedRateLimit = true; + } catch (InterruptedException e) { + System.out.println("interrupted"); + } catch (ExecutionException e) { + System.out.println("exception"); + } + } + + System.out.println(exceedRateLimit==false? "没有超过限制" : "超过限制"); + } +} + +class ResetInstanceCallable implements Callable { + + private String instanceId; + private CountDownLatch countDownLatch; + + public ResetInstanceCallable(String instanceId, CountDownLatch countDownLatch) { + this.instanceId = instanceId; + this.countDownLatch = countDownLatch; + } + + @Override + public Boolean call() { + throw new MyException(); + } +} +