为什么ByteArrayInputStream不返回预期的结果?

时间:2011-09-21 10:10:25

标签: java telnet

我正在尝试通过telnet与Windows服务器中的应用程序进行交互,因此我使用的是TelnetClient()方法。我可以使用System.in.read()进行交互(发送命令和检索结果),但是我希望这个程序能够在不使用任何键盘输入的情况下自动运行。所以,我的问题是,为什么System.in.read()工作,但ByteArrayInputStream不工作?

到目前为止,这是我的代码:

public class telnetExample2 implements Runnable, TelnetNotificationHandler{
 static TelnetClient tc = null;
 public static void main (String args[]) throws IOException, InterruptedException{
  tc = new TelnetClient();
   while (true){
    try{
     tc.connect("192.168.1.13", 8999);
     }
     catch (SocketException ex){
      Logger.getLogger(telnetExample2.class.getName()).log(Level.SEVERE, null,ex);
     }
    Thread reader = new Thread(new telnetExample2());
    tc.registerNotifHandler(new telnetExample2());
    String command = "getversion"; //this is the command i would like to write
    OutputStream os = tc.getOutputStream();
    InputStream is = new ByteArrayInputStream(command.getBytes("UTF-8")); //i'm using UTF-8 charset encoding here
    byte[] buff = new byte[1024];
    int ret_read = 0;
    do{
     ret_read = is.read(buff);
     os.write(buff, 0, 10)
     os.flush();
    while(ret_read>=0);
    }
 }

public void run(){
 InputStream instr = tc.getInputStream();
 try{
  byte[] buff = new byte[1024];
  int ret_read = 0;
   do{
    ret_read = instr.read(buff);
    if(ret_read >0){
     System.out.print(new String(nuff, 0, ret_read));
    }
   while(ret_read>=0);}
  catch(Exception e){
  System.err.println("Exception while reading socket:" + e.getMessage());
  }
 }

public void receiveNegotiation(int i, int ii){
 throw new UnsupportedOperationException("Not supported");
 }
}

1 个答案:

答案 0 :(得分:6)

InputStream is = new ByteArrayInputStream(command.getBytes("UTF-8")); //i'm using UTF-8 charset encoding here
byte[] buff = new byte[1024];
int ret_read = 0;
do{
 ret_read = is.read(buff);
 os.write(buff, 0, 10)
 os.flush();
while(ret_read>=0);
}

您可以将那些不起作用的9行减少到os.write(command.getBytes("UTF-8"));

为什么你认为将最多1024个字节读入缓冲区然后只写出前十个字节才能工作是一个谜。