Java Socket实现多线程聊天室：代码解析与运行流程

/**
 * @类名 CloseUtils
 * @描述 TODO 工具类，统一释放资源
 */
public class CloseUtils {
    public static void close(Closeable... targets ) {
        for(Closeable target:targets) {
            try {
                if(null!=target) {
                    target.close();
                }
            }catch(Exception e) {
                // 静默处理或记录日志
            }
        }
    }
}

public class Client {
   	public static void main(String[] args) throws UnknownHostException, IOException {
   		System.out.println("-----Client-----");
   		BufferedReader br =new BufferedReader(new InputStreamReader(System.in));
   		System.out.println("请输入用户名:");
   		String name =br.readLine();
   		// 1、建立连接: 使用Socket创建客户端 +服务的地址和端口
   		Socket client =new Socket("localhost",8888);
   		// 2、开启多线程分别处理收发
   		new Thread(new Send(client,name)).start();  
   		new Thread(new Receive(client)).start();
   	}
}

public class Send implements Runnable {
	private BufferedReader console ;
	private DataOutputStream dos;
	private Socket client;
	private boolean isRunning;
	private String name;
	
	public Send(Socket client,String name) {
		this.client =client;
		console =new BufferedReader(new InputStreamReader(System.in));
		this.isRunning = true;
		this.name = name;
		try {
			dos =new DataOutputStream(client.getOutputStream());
			// 连接成功后先发送名称告知服务器
			send(name);
		} catch (IOException e) {
			release();
		}	  
	}
	
	@Override
	public void run() {
		while(isRunning) {
			String msg = getStrFromConsole();
			if(!msg.equals("")) {
				send(msg);
			}
		}
	}	  
	
	private void send(String msg) {
		try {
			dos.writeUTF(msg);
			dos.flush();
		} catch (IOException e) {
			release();
		}
	}
	
	private String getStrFromConsole() {
		try {
			return  console.readLine();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return "";
	}
	
	private void release() {
		this.isRunning = false;
		CloseUtils.close(dos,client);
	}
}

public class Receive implements Runnable {
	private DataInputStream dis ;
	private Socket client;
	private boolean isRunning;
	
	public Receive(Socket client) {
		this.client = client;
		this.isRunning = true;
		try {
			dis =new DataInputStream(client.getInputStream());
		} catch (IOException e) {
			release();
		}
	}
	
	private String receive() {
		String msg ="";
		try {
			msg =dis.readUTF();
		} catch (IOException e) {
			release();
		}
		return msg;
	}
	
	@Override
	public void run() {   	  
		while(isRunning) {
			String msg =receive();
			if(!msg.equals("")) {
				System.out.println(msg);
			}
		}
	}
	
	private void release() {
		this.isRunning = false;
		CloseUtils.close(dis,client);
	}
}

public class Chat {

	// 使用线程安全的动态数组存放所有在线通道
	private static CopyOnWriteArrayList<Channel> all =new CopyOnWriteArrayList<Channel>();

	public static void main(String[] args) throws IOException {
		System.out.println("-----Server-----");
		// 1、指定端口 使用ServerSocket创建服务器
		ServerSocket server =new ServerSocket(8888);
		// 2、主线程无限循环阻塞等待连接
		while(true) {
					Socket  client =server.accept(); 	
					System.out.println("一个客户端建立了连接");
					// 为每个连接创建一个专门的Channel处理
					Channel c =new Channel(client);
					all.add(c); // 管理所有的成员
					new Thread(c).start();   		
				}  	  
		}
	}
	// 内部静态类：代表一个独立的通信通道
	static class Channel implements Runnable{
		// ... (此处省略部分属性与构造方法见下文分析)
	}
}

	private void sendOthers(String msg,boolean isSys) {
		boolean isPrivate = msg.startsWith("@");
		if(isPrivate) { // 私聊处理
			int idx =msg.indexOf(":");
			String targetName = msg.substring(1,idx);
			msg = msg.substring(idx+1);
			for(Channel other: all) {
				if(other.name.equals(targetName)) {// 找到目标
					other.send(this.name +"悄悄地对您说:"+msg);
					break;
				}
			}
		}else {   		  
			for(Channel other: all) {
				if(other==this) continue; // 跳过自己
				if(!isSys) {
					other.send(this.name +"对所有人说:"+msg);
				}else {
					other.send(msg); // 系统消息
				}
			}
		}
	}