feat: 中介者模式

design-patterns/src/main/java/io/walkers/planes/pandora/design/patterns/mediator/ChatServer.java

@@ -0,0 +1,29 @@
+package io.walkers.planes.pandora.design.patterns.mediator;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 中介者角色：聊天服务器
+ *
+ * @author planeswalker23
+ * @date 2022/2/22
+ */
+public class ChatServer {
+
+    private List<User> users = new ArrayList<>();
+
+    public void register(User user) {
+        users.add(user);
+        user.setChatServer(this);
+        System.out.println("用户" + user.getUsername() + "加入聊天室");
+    }
+
+    public void reply(Message message) {
+        for (User user1:users) {
+            if (message.getTargetGroup().equals(user1.getGroup())) {
+                user1.receive(message);
+            }
+        }
+    }
+}

design-patterns/src/main/java/io/walkers/planes/pandora/design/patterns/mediator/Message.java

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+package io.walkers.planes.pandora.design.patterns.mediator;
+
+/**
+ * @author planeswalker23
+ * @date 2022/2/22
+ */
+public class Message {
+    // 发送内容
+    private String content;
+    // 发送组
+    private String targetGroup;
+    // 发送者
+    private User sender;
+
+    public Message(String content, String targetGroup, User sender) {
+        this.content = content;
+        this.targetGroup = targetGroup;
+        this.sender = sender;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+    public String getTargetGroup() {
+        return targetGroup;
+    }
+
+    public void setTargetGroup(String targetGroup) {
+        this.targetGroup = targetGroup;
+    }
+
+    public User getSender() {
+        return sender;
+    }
+
+    public void setSender(User sender) {
+        this.sender = sender;
+    }
+}

design-patterns/src/main/java/io/walkers/planes/pandora/design/patterns/mediator/Test.java

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+package io.walkers.planes.pandora.design.patterns.mediator;
+
+/**
+ * @author planeswalker23
+ * @date 2022/2/22
+ */
+public class Test {
+    public static void main(String[] args) {
+        ChatServer chatServer = new ChatServer();
+        User user1 = new User("user1", "A");
+        User user2 = new User("user2", "A");
+        User user3 = new User("user3", "B");
+        chatServer.register(user1);
+        chatServer.register(user2);
+        chatServer.register(user3);
+
+        Message message = new Message("你好", "A", user3);
+        user3.send(message);
+    }
+}

design-patterns/src/main/java/io/walkers/planes/pandora/design/patterns/mediator/User.java

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+package io.walkers.planes.pandora.design.patterns.mediator;
+
+/**
+ * 同事角色：用户
+ *
+ * @author planeswalker23
+ * @date 2022/2/22
+ */
+public class User {
+    // 用户昵称
+    private String username;
+    // 用户群组
+    private String group;
+    // 用户所属聊天服务器
+    private ChatServer chatServer;
+
+    public User(String username, String group) {
+        this.username = username;
+        this.group = group;
+    }
+
+    // 接收消息
+    public void receive(Message message) {
+        System.out.println("用户" + this.username + "收到用户" + message.getSender().getUsername() + "发来的消息，内容为：" + message.getContent());
+    }
+
+    // 发送消息
+    public void send(Message message) {
+        System.out.println("用户" + this.username + "向群组" + this.group + "的用户发出消息，内容为：" + message.getContent());
+        chatServer.reply(message);
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getGroup() {
+        return group;
+    }
+
+    public void setGroup(String group) {
+        this.group = group;
+    }
+
+    public ChatServer getChatServer() {
+        return chatServer;
+    }
+
+    public void setChatServer(ChatServer chatServer) {
+        this.chatServer = chatServer;
+    }
+}