如何使用线程从另一个类调用不同的函数

Posted 2023-04-01

【中文标题】如何使用线程从另一个类调用不同的函数

【英文标题】：How to use threading to call different functions from another class

【发布时间】：2015-01-16 05:53:39

【问题描述】：

我有一个服务器类，它具有三种方法启动/停止/重定向。请在下面找到代码。

public class Syslog

private static final int PORT = 519;
private static final int BUFFER_SIZE = 10000;
private static boolean server_status=false;


public static void startServer()

server_status=true;


public static void stopServer()

server_status=false;


public void redirectToFile(byte[] bs) throws IOException

String data=new String(bs);

File file = new File("C:\\audit_log.txt");

// if file doesn't exists, then create it
if (!file.exists()) 
    file.createNewFile();


FileWriter fw = new FileWriter(file.getAbsoluteFile());
BufferedWriter bw = new BufferedWriter(fw);
bw.write(data);
bw.close();

System.out.println("Done");



public void runServer() throws IOException

DatagramSocket socket = new DatagramSocket(PORT);
DatagramPacket packet = new DatagramPacket(new      byte[BUFFER_SIZE],BUFFER_SIZE);

System.out.println("Receiving data from the socket and redirecting it to a  file C:\\audit_log.txt");
while(server_status)

packet.setLength(BUFFER_SIZE);
socket.receive(packet);

System.out.printf("Got %d bytes from  %s%n",packet.getLength(),packet.getSocketAddress());
System.out.write(packet.getData());

redirectToFile(packet.getData());


socket.close();

我有一个 junit 测试，我想在 @beforeclass 中启动服务器并在 @afterclass 中停止它。我还需要在测试执行期间调用 runServer() 。我尝试使用线程，但在实施过程中真的很困惑。有人可以指出一种设计方法来处理这个问题。然后我会尝试相应地编码。

【参考方案1】：

建议你在runServer() 中产生一个线程。这样您就不必在 JUnit 测试中处理线程。像这样的：

private Thread serverThread;
IOException thrown;

public void runServer() throws IOException 
    if (serverThread != null) 
        throw new IOException("Server is already running");
    
    serverThread = new Thread(new Runnable() 
        public void run() 
            DatagramSocket socket = null;
            try 
                socket = new DatagramSocket(PORT);
                DatagramPacket packet = new DatagramPacket(new byte[BUFFER_SIZE], BUFFER_SIZE);
                while (server_status) 
                    packet.setLength(BUFFER_SIZE);
                    socket.receive(packet);
                    System.out.write(packet.getData());
                    redirectToFile(packet.getData());
                
             catch (IOException e) 
                thrown = e;
             finally 
                serverThread = null;
                if (socket != null) socket.close();
            
        
    );
    serverThread.start();

【讨论】：

谢谢。我可以使用上面的代码稍作修改。

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