Android網絡編程：IOExceptions和StackOverflowError

Question

在我的Android應用程序中，我嘗試連接到本地服務器上的端口以獲取一些數據包。我一直包裹到代碼中的一些嘗試&趕上的，但下面的代碼：

address = "192.168.175.82"; 
public void run() { 
    try { 
    smtpSocket = new Socket(address, 60001); 

     os = new DataOutputStream(smtpSocket.getOutputStream()); 
     is = new DataInputStream(smtpSocket.getInputStream()); 
    } catch (UnknownHostException e) { 
     System.err.println("Don't know about host: " + address); 
     run(); 
    } catch (IOException e) { 
     System.err.println("Couldn't get I/O for the connection to: " + address); 
     run(); 
    } catch (Exception e) { 
    System.out.println("retry"); 
    run(); 
    } 

如存在服務器不在，我明明得到了IOException異常幾次（如幾百次）之前，我收到了堆棧溢出錯誤和應用程序崩潰。

01-20 22:21:32.526: ERROR/AndroidRuntime(5678): java.lang.StackOverflowError 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.util.Hashtable.get(Hashtable.java:282) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.util.Properties.getProperty(Properties.java:177) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.lang.System.getProperty(System.java:440) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.lang.System.getProperty(System.java:412) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.lang.Boolean.getBoolean(Boolean.java:174) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at org.apache.harmony.luni.net.NetUtil$Action.run(NetUtil.java:89) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at org.apache.harmony.luni.net.NetUtil$Action.run(NetUtil.java:80) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.security.AccessController.doPrivilegedImpl(AccessController.java:264) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.security.AccessController.doPrivileged(AccessController.java:84) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at org.apache.harmony.luni.net.NetUtil.preferIPv6Addresses(NetUtil.java:51) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at org.apache.harmony.luni.net.PlainSocketImpl.bind(PlainSocketImpl.java:190) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.net.Socket.startupSocket(Socket.java:777) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.net.Socket.tryAllAddresses(Socket.java:192) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.net.Socket.<init>(Socket.java:256) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at java.net.Socket.<init>(Socket.java:220) 
01-20 22:21:32.526: ERROR/AndroidRuntime(5678):  at com.example.sockets.ReadSocket.run(ReadSocket.java:83) 

任何人都可以請指出我正確的方向如何讓這個工作？也許我應該先以某種方式測試連接（如果有的話，請說怎麼樣？） 感謝

克里斯

Answer 1

對於初學者，請放棄遞歸調用。這將擺脫堆棧溢出。 用循環代替它，並在每次不成功的迭代中睡眠

public void run() { 
    boolean connected = false; 
    while(!connected) 
    { 
    try { 
     smtpSocket = new Socket(address, 60001); 

      os = new DataOutputStream(smtpSocket.getOutputStream()); 
      is = new DataInputStream(smtpSocket.getInputStream()); 


     connected = true; 
    } catch (UnknownHostException e) { 
     System.err.println("Don't know about host: " + address); 

    } catch (IOException e) { 
     System.err.println("Couldn't get I/O for the connection to: " + address); 

     } catch (Exception e) { 
     System.out.println("retry"); 

     } 
     if (!connected) 
      Thread.sleep(1000) 
     } 
    } 

Answer 2

你可以嘗試isConnected()和isBound()您的插座上請檢查是否已連接或不試圖獲得一個前的InputStream。