我正在使用这个我不完全理解的类(JSch),但我对它的工作原理有一个粗略的了解。如果 exitStatus 不是我想要的,我试图抛出一个异常。但是,使用
e.printStackTrace() or e.printStackTrace(System.err) //does nothing
e.printStackTrace(System.out) //prints the whole stack trace.
我以前从未见过这个问题,所以我想知道是我不理解的 API 导致了问题还是异常堆栈跟踪的工作方式不同?我有一种感觉,使用 apache log4j 会起作用,但我懒得仅仅为了测试目的而设置它,它不会回答为什么会发生这种情况的困惑。
如果有兴趣,这里是代码(我想在 exitStatus != 0 时抛出异常):
Channel channel = null;
int exitStatus = 1;
System.out.println(command);
try {
channel = session.openChannel("exec");
ChannelExec channelExec = (ChannelExec) channel;
channelExec.setPty(true);
channelExec.setCommand(command);
channelExec.setInputStream(null);
channelExec.setErrStream(System.err);
InputStream in = channel.getInputStream();
channel.connect();
byte[] tmp=new byte[1024];
int timeout = 0;
while (true){
while (in.available() > 0) {
timeout = 0; // if read success, reset timeout
int i = in.read(tmp, 0, 1024);
if (i < 0)break;
String status = new String(tmp, 0, i);
/*System.out.println(status);*/
if (status.toLowerCase().contains("incorrect password")) {
channel.disconnect();
} else if (status.toLowerCase().contains("password")) {
OutputStream out = channel.getOutputStream();
out.write(args);
out.write('\n');
out.close();
}
}
if (channel.isClosed()){
exitStatus = channel.getExitStatus();
break;
}
try { Thread.sleep(1000); } catch (Exception ee) { ee.printStackTrace(); }
// nothing reads for 4 turns but stream is not closing, probably waiting for user input so exit
if (timeout++ > 5) {
break;
}
}
} catch (IOException ioe) {
throw new ApplicationException(ioe);
} catch (JSchException je) {
throw new ApplicationException("Could not create an exec channel for SSH. ", je);
} finally {
if (channel.isConnected()) channel.disconnect();
}
//if (exitStatus != 0) throw new MyCustomException(errormsg)
谢谢。