Java基于中介者模式实现多人聊天室功能示例

package com.demo.mediator;
import com.demo.colleague.IUser;
/**
 * 中介者接口
 *
 * @author
 *
 */
public interface IMediator {
  /**
   * 注册用户信息
   *
   * @param user
   */
  public void regist(IUser user);
  /**
   * 发送消息给所有人
   *
   * @param user
   *      发送消息人
   */
  public void notifyAllMessage(IUser user);
}

package com.demo.mediator;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import com.demo.colleague.IUser;
/**
 * 中介者实现类
 *
 * @author
 *
 */
public class ConcreteMediator implements IMediator {
  private final List<IUser> list = new ArrayList<IUser>();
  /**
   * 注册用户信息
   *
   * @param user
   */
  public void regist(IUser user) {
    if (user != null && !list.contains(user)) {
      list.add(user);
    }
  }
  /**
   * 发送消息
   *
   * @param user
   *      发送消息人
   */
  public void notifyAllMessage(IUser user) {
    Iterator<IUser> iterator = list.iterator();
    IUser tmpUser = null;
    while (iterator.hasNext()) {
      tmpUser = iterator.next();
      if (tmpUser != null && !tmpUser.equals(user)) {
        // 排除发送消息用户
        tmpUser.receiveMessage(user.getMessage());
      }
    }
  }
}

package com.demo.colleague;
/**
 * 用户接口
 *
 * @author
 *
 */
public interface IUser
{
  /**
   * 接收消息
   *
   * @param message
   *      消息
   */
  public void receiveMessage(String message);
  /**
   * 发送消息
   *
   * @param message
   *      消息
   */
  public void sendMessage(String message);
  /**
   * 获得发送的消息内容
   *
   * @return
   */
  public String getMessage();
}

package com.demo.colleague;
import com.demo.mediator.IMediator;
/**
 * 抽象用户信息
 *
 * @author
 *
 */
public abstract class AbstractUser implements IUser
{
  // 中介者
  protected IMediator mediator;
  // 姓名
  protected String name;
  // 消息
  protected String message;
  public AbstractUser(IMediator mediator, String name)
  {
    this.mediator = mediator;
    this.name = name;
  }
  /**
   * 发送消息
   *
   * @param message
   *      消息
   */
  public void sendMessage(String message)
  {
    this.message = message;
    System.out.println(this.name + " 说:" + this.message);
    mediator.notifyAllMessage(this);
  }
  public String getMessage()
  {
    return message;
  }
}

package com.demo.colleague;
import com.demo.mediator.IMediator;
/**
 * 用户A
 *
 * @author
 *
 */
public class UserA extends AbstractUser {
  public UserA(IMediator mediator, String name) {
    super(mediator, name);
    // 注册到中介者对象中
    mediator.regist(this);
  }
  /**
   * 接收消息方法
   */
  public void receiveMessage(String message) {
    System.out.println("User A Received Message : " + message);
  }
}

package com.demo.colleague;
import com.demo.mediator.IMediator;
/**
 * 用户B
 *
 * @author
 *
 */
public class UserB extends AbstractUser {
  public UserB(IMediator mediator, String name) {
    super(mediator, name);
    // 注册到中介者对象中
    mediator.regist(this);
  }
  /**
   * 接收消息方法
   */
  public void receiveMessage(String message) {
    System.out.println("User B Received Message : " + message);
  }
}

package com.demo.colleague;
import com.demo.mediator.IMediator;
/**
 * 用户C
 *
 * @author
 *
 */
public class UserC extends AbstractUser {
  public UserC(IMediator mediator, String name) {
    super(mediator, name);
    // 注册到中介者对象中
    mediator.regist(this);
  }
  /**
   * 接收消息方法
   */
  public void receiveMessage(String message) {
    System.out.println("User C Received Message : " + message);
  }
}

package com.demo;
import com.demo.colleague.IUser;
import com.demo.colleague.UserA;
import com.demo.colleague.UserB;
import com.demo.colleague.UserC;
import com.demo.mediator.ConcreteMediator;
import com.demo.mediator.IMediator;
/**
 *
 * 主应用程序
 *
 * @author
 *
 */
public class Client {
  /**
   * @param args
   */
  public static void main(String[] args) {
    // 创建聊天室（中介者）
    IMediator mediator = new ConcreteMediator();
    // 创建用户信息
    IUser userA = new UserA(mediator, "张三");
    IUser userB = new UserB(mediator, "李四");
    IUser userC = new UserC(mediator, "王五");
    System.out
        .println("============================================================");
    userA.sendMessage("大家好，我叫张三！初来乍到，请多多关照！");
    System.out
        .println("============================================================\n");
    System.out
        .println("============================================================");
    userB.sendMessage("你好，我叫李四，欢迎加入！");
    System.out
        .println("============================================================\n");
    System.out
        .println("============================================================");
    userC.sendMessage("我是王五，欢迎欢迎！");
    System.out
        .println("============================================================\n");
  }
}