Java中能接受其他通信实体链接请求的类是ServerSocket,ServerSocket对象用于监听来自客户端的Socket链接,如果没有链接,它将一直等待。如果接收到一个客户端Socket的连接请求,ServerSocket的accept()方法将返回一个与客户端Socket对应的Socket(每个TCP连接有两个Socket),否则该方法将一直阻塞,线程也被阻塞。
服务端思路:服务端应该包含多个线程,每个Socket对应一个线程,这个线程负责读取该Socket对应输入流的数据(从客户端发送过来的数据),并将读到的数据向每个Socket输出流发送一次(将一个客户端发送过来的数据“广播”给其他客户端)。
服务端代码:
//服务端主类
public class MyServer
{
public static List<Socket socketList = Collections.synchronizedList(new ArrayList<Socket ());
public static void main(String[] args) throws IOException
{
ServerSocket ss = new ServerSocket(30000);
while (true)
{
//此行代码会阻塞,将一直等待别人的连接
Socket s = ss.accept();
socketList.add(s);
//每当客户端连接后启动一个ServerThread线程为该客户端服务
new Thread(new ServerThread(s)).start();
}
}
}
public class ServerThread implements Runnable
{
//定义当前线程所处理的Socket
Socket s = null;
//该线程所处理的Socket对应的输入流
BufferedReader br = null;
public ServerThread(Socket s) throws IOException
{
this.s = s;
//初始化该Socket对应的输入流
br = new BufferedReader(new InputStreamReader(s.getInputStream()));
}
@Override
public void run()
{
try
{
String content = null;
//采用循环不断地从Socket中读取客户端发送来的数据
while ((content = readFromClient()) != null)
{
//遍历socketList中的每个Socket
//将读到的内容向每个Socket发送一次
for (Socket s : MyServer.socketList)
{
PrintStream ps = new PrintStream(s.getOutputStream());
ps.println(content);
}
}
}
catch (IOException e)
{
e.printStackTrace();
}
}
//定义读取客户端数据的方法
private String readFromClient()
{
try
{
return br.readLine();
}
//如果捕获到异常,则表明该Socket对应的客户端已经关闭
catch (IOException e)
{
//删除该Socket
MyServer.socketList.remove(s);
}
return null;
}
}
客户端思路:将用户输入的数据写入Socket对应的输入流中;开启一个子线程读取Socket对应输入流中的数据(从服务端发送过来的数据),并通过Handler将读取的数据发送到主线程来更新UI。
//用户界面Activity
public class MainActivity extends Activity
{
private EditText mReceiverMsg;
private Button mSendBtn;
private EditText mSendMsg;
Handler handler = new Handler()
{
@Override
public void handleMessage(Message msg)
{
Log.d("mainActivity" , "okk");
mReceiverMsg.append(msg.obj.toString());
}
};
private Socket s;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
initView();
initSocket();
mSendBtn.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
sendData();
}
});
}
private void initSocket()
{
new Thread()
{
@Override
public void run()
{
try
{
s = new Socket("192.168.1.101" , 30000);
new Thread(new ClientThread(s , handler)).start();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}.start();
}
private void initView()
{
mReceiverMsg = (EditText) findViewById(R.id.receiver_message);
mSendMsg = (EditText) findViewById(R.id.send_message);
mSendBtn = (Button) findViewById(R.id.send_button);
}
private void sendData()
{
try
{
//获取该Socket对应的输出流
PrintStream ps = new PrintStream(s.getOutputStream());
if (TextUtils.isEmpty(mSendMsg.getText()))
{
Toast.makeText(this , "请输入信息" , Toast.LENGTH_LONG).show();
return;
}
ps.println(mSendMsg.getText().toString());
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
public class ClientThread implements Runnable
{
//该线程负责处理的Socket
private Socket ss;
//该线程所处理的Socket对应的输入流
BufferedReader br = null;
Handler handler;
public ClientThread(Socket s , Handler handler) throws IOException
{
this.ss = s;
this.handler = handler;
br = new BufferedReader(new InputStreamReader(ss.getInputStream()));
}
@Override
public void run()
{
try
{
String content = null;
while ((content = br.readLine()) != null)
{
Message msg = new Message();
msg.obj = content;
handler.sendMessage(msg);
}
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
先运行上面程序中的MyServer类,该类运行只是作为服务端。再启动多个模拟器,运行安装客户端的程序作为多个客户端,然后可以再任何一个客户端通过Edit输入一些内容,点击发送就可以在任何一个客户端看到刚刚输入的内容。
以上就是本文的全部内容,希望对大家的学习有所帮助。