{
8 | /**
9 | * 是否包含下一个元素
10 | *
11 | * @return
12 | */
13 | boolean hasNext();
14 |
15 | /**
16 | * 获取元素
17 | *
18 | * @return
19 | */
20 | E next();
21 |
22 | }
23 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/creational/singleton/SingletonEH.java:
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1 | package me.hvkcoder.java_basic.desgin_patterns.creational.singleton;
2 |
3 | /**
4 | * 单例模式饿汉式
5 | *
6 | * 类加载到内存后，就实例化一个单例，JVM保证线程安全，容易造成资源浪费
7 | *
8 | * @author h-vk
9 | * @since 2020-02-07
10 | */
11 | public class SingletonEH {
12 |
13 | private static final SingletonEH INSTANCE = new SingletonEH();
14 |
15 | private SingletonEH() {
16 | }
17 |
18 | public static SingletonEH getInstance() {
19 | return INSTANCE;
20 | }
21 |
22 | public static void main(String[] args) {
23 | // 单例模式饿汉式
24 | SingletonEH instanceEH_1 = SingletonEH.getInstance();
25 | SingletonEH instanceEH_2 = SingletonEH.getInstance();
26 | System.out.println(instanceEH_1 == instanceEH_2);
27 | }
28 | }
29 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/creational/singleton/SingletonEnum.java:
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1 | package me.hvkcoder.java_basic.desgin_patterns.creational.singleton;
2 |
3 | /**
4 | * 单例模式枚举方式
5 | *
6 | * 不仅可以解决线程同步，还可以防止反序列
7 | *
8 | * @author h-vk
9 | * @since 2020-02-10
10 | */
11 | public enum SingletonEnum {
12 |
13 | INSTANCE;
14 |
15 | public static void main(String[] args) {
16 | for (int i = 0; i < 100; i++) {
17 | new Thread(() -> System.out.println(SingletonEnum.INSTANCE.hashCode())).start();
18 | }
19 | }
20 | }
21 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/creational/singleton/SingletonInnerClass.java:
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1 | package me.hvkcoder.java_basic.desgin_patterns.creational.singleton;
2 |
3 | /**
4 | * 静态内部类方式
5 | *
6 | * JVM 保证单例，加载外部类时不会加载内部类，这样可以实现懒加载
7 | *
8 | * @author h-vk
9 | * @since 2020-02-10
10 | */
11 | public class SingletonInnerClass {
12 | private SingletonInnerClass() {
13 | }
14 |
15 | public static SingletonInnerClass getInstance() {
16 | return SingletonInnerClassHolder.INSTANCE;
17 | }
18 |
19 | public static void main(String[] args) {
20 | for (int i = 0; i < 100; i++) {
21 | new Thread(() -> System.out.println(SingletonInnerClass.getInstance())).start();
22 | }
23 | }
24 |
25 | private static class SingletonInnerClassHolder {
26 | public static final SingletonInnerClass INSTANCE = new SingletonInnerClass();
27 | }
28 | }
29 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/creational/singleton/SingletonLH.java:
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1 | package me.hvkcoder.java_basic.desgin_patterns.creational.singleton;
2 |
3 | /**
4 | * 单例模式 懒汉式
5 | *
6 | * 通过双重检查 + 代码块上锁，解决多线程获得的对象不是同一对象问题
7 | *
8 | * @author h-vk
9 | * @since 2020-02-10
10 | */
11 | public class SingletonLH {
12 | private static volatile SingletonLH INSTANCE;
13 |
14 | private SingletonLH() {
15 | }
16 |
17 | public static SingletonLH getInstance() {
18 | // 双重检查
19 | if (INSTANCE == null) {
20 | // 减小同步代码块
21 | synchronized (SingletonLH.class) {
22 | if (INSTANCE == null) {
23 | try {
24 | Thread.sleep(1);
25 | } catch (InterruptedException e) {
26 | e.printStackTrace();
27 | }
28 | INSTANCE = new SingletonLH();
29 | }
30 | }
31 | }
32 | return INSTANCE;
33 | }
34 |
35 | public static void main(String[] args) {
36 | for (int i = 0; i < 100; i++) {
37 | new Thread(() -> System.out.println(SingletonLH.getInstance())).start();
38 | }
39 | }
40 | }
41 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/creational/singleton/SingletonLazyLoading.java:
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1 | package me.hvkcoder.java_basic.desgin_patterns.creational.singleton;
2 |
3 | /**
4 | * 单例模式懒汉式
5 | *
6 | * 多线程访问时会出现问题,可以通过加入 synchronized 关键字加锁解决该问题，但带来了效率下降
7 | *
8 | * @author h-vk
9 | * @since 2020-02-10
10 | */
11 | public class SingletonLazyLoading {
12 | private static volatile SingletonLazyLoading INSTANCE;
13 |
14 | private SingletonLazyLoading() {
15 | }
16 |
17 | public static synchronized SingletonLazyLoading getInstance() {
18 | if (INSTANCE == null) {
19 | try {
20 | Thread.sleep(100);
21 | } catch (InterruptedException e) {
22 | e.printStackTrace();
23 | }
24 | INSTANCE = new SingletonLazyLoading();
25 | }
26 | return INSTANCE;
27 | }
28 |
29 | public static void main(String[] args) {
30 | // 单例模式懒汉式
31 | for (int i = 0; i < 100; i++) {
32 | new Thread(() -> System.out.println(SingletonLazyLoading.getInstance())).start();
33 | }
34 | }
35 | }
36 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/creational/singleton/practice/TicketMaker.java:
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1 | package me.hvkcoder.java_basic.desgin_patterns.creational.singleton.practice;
2 |
3 | /**
4 | * 习题 1 每次调用 getNextTicketNumber 方法都会返回 1000、1001、1002....的数列
5 | *
6 | *
使用双检锁的方式解决
7 | *
8 | * @author h-vk
9 | * @since 2020/5/30
10 | */
11 | public class TicketMaker {
12 | private static volatile TicketMaker INSTANCE;
13 | private int ticket = 1000;
14 |
15 | private TicketMaker() {}
16 |
17 | public static TicketMaker getInstance() {
18 | if (INSTANCE == null) {
19 | synchronized (TicketMaker.class) {
20 | if (INSTANCE == null) INSTANCE = new TicketMaker();
21 | }
22 | }
23 | return INSTANCE;
24 | }
25 |
26 | public static void main(String[] args) {
27 | for (int i = 0; i < 100; i++) {
28 | new Thread(() -> System.out.println(TicketMaker.getInstance().getNextTicketNumber())).start();
29 | }
30 | }
31 |
32 | public int getNextTicketNumber() {
33 | return ticket++;
34 | }
35 | }
36 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/structural/decorator/Decorator.java:
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1 | package me.hvkcoder.java_basic.desgin_patterns.structural.decorator;
2 |
3 | /**
4 | * 装饰器
5 | *
6 | * @author h-vk
7 | * @since 2020/6/28
8 | */
9 | public abstract class Decorator implements Drink {
10 | private Drink drink;
11 |
12 | public Decorator(Drink drink) {
13 | this.drink = drink;
14 | }
15 |
16 | @Override
17 | public double money() {
18 | return drink.money();
19 | }
20 |
21 | @Override
22 | public String desc() {
23 | return drink.desc();
24 | }
25 | }
26 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/structural/decorator/Drink.java:
--------------------------------------------------------------------------------
1 | package me.hvkcoder.java_basic.desgin_patterns.structural.decorator;
2 |
3 | /**
4 | * 抽象组件
5 | *
6 | * @author h-vk
7 | * @since 2020/6/28
8 | */
9 | public interface Drink {
10 | public double money();
11 |
12 | public String desc();
13 | }
14 |
--------------------------------------------------------------------------------
/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/structural/decorator/Main.java:
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1 | package me.hvkcoder.java_basic.desgin_patterns.structural.decorator;
2 |
3 | /**
4 | * @author h-vk
5 | * @since 2020/6/28
6 | */
7 | public class Main {
8 | public static void main(String[] args) {
9 | Drink redBeanSoya = new RedBean(new Soya());
10 | System.out.println(redBeanSoya.desc());
11 | System.out.println(redBeanSoya.money());
12 | }
13 | }
14 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/structural/decorator/RedBean.java:
--------------------------------------------------------------------------------
1 | package me.hvkcoder.java_basic.desgin_patterns.structural.decorator;
2 |
3 | /**
4 | * 具体装饰
5 | *
6 | * @author h-vk
7 | * @since 2020/6/28
8 | */
9 | public class RedBean extends Decorator {
10 | public RedBean(Drink drink) {
11 | super(drink);
12 | }
13 |
14 | @Override
15 | public double money() {
16 | return super.money() + 3.2;
17 | }
18 |
19 | @Override
20 | public String desc() {
21 | return super.desc() + "红豆";
22 | }
23 | }
24 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/desgin_patterns/structural/decorator/Soya.java:
--------------------------------------------------------------------------------
1 | package me.hvkcoder.java_basic.desgin_patterns.structural.decorator;
2 |
3 | /**
4 | * 被装饰者
5 | *
6 | * @author h-vk
7 | * @since 2020/6/28
8 | */
9 | public class Soya implements Drink {
10 | @Override
11 | public double money() {
12 | return 5;
13 | }
14 |
15 | @Override
16 | public String desc() {
17 | return "纯豆浆";
18 | }
19 | }
20 |
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/java/java-basic/src/main/java/me/hvkcoder/java_basic/io/netty/custom/codec/InvokerProtocol.java:
--------------------------------------------------------------------------------
1 | package me.hvkcoder.java_basic.io.netty.custom.codec;
2 |
3 | import lombok.Data;
4 |
5 | import java.io.Serial;
6 | import java.io.Serializable;
7 |
8 | /**
9 | * @author h_vk
10 | * @since 2024/3/29
11 | */
12 | @Data
13 | public class InvokerProtocol implements Serializable {
14 | @Serial
15 | private static final long serialVersionUID = -3113587718295415460L;
16 |
17 | /**
18 | * 类名
19 | */
20 | private String className;
21 |
22 | /**
23 | * 方法名
24 | */
25 | private String methodName;
26 |
27 | /**
28 | * 参数类型
29 | */
30 | private Class[] params;
31 |
32 | /**
33 | * 参数值
34 | */
35 | private Object[] values;
36 | }
37 |
--------------------------------------------------------------------------------
/java/java-basic/src/main/java/me/hvkcoder/java_basic/io/netty/custom/codec/InvokerProtocolDecoder.java:
--------------------------------------------------------------------------------
1 | package me.hvkcoder.java_basic.io.netty.custom.codec;
2 |
3 | import io.netty.buffer.ByteBuf;
4 | import io.netty.channel.ChannelHandlerContext;
5 | import io.netty.handler.codec.ByteToMessageDecoder;
6 |
7 | import java.io.ByteArrayInputStream;
8 | import java.io.ObjectInputStream;
9 | import java.util.List;
10 |
11 | /**
12 | * @author h_vk
13 | * @since 2024/3/29
14 | */
15 | public class InvokerProtocolDecoder extends ByteToMessageDecoder {
16 | @Override
17 | protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List