Java，Telnet，检查InputStream中的字符串 [英] Java, Telnet, check for String in an InputStream
问题描述
我很生.我正在尝试编写Java类以与Telnet进行交互.我看到Apache Commons和Jsacpe拥有API.我正在使用Jscape的Sinetfactory.一旦telnet.connect()发生，我要连接的Telnet就会提示输入"User name ?:".我需要验证此提示是否确实在发生，因此在发生其他情况时，我不只是写下答案.我对此没有经验，并且肯定有一个简单的答案，只是想知道是否有人可以提供帮助.
I am fairly raw. I am trying to write a Java class to interact with Telnet. I saw that Apache Commons and Jsacpe had APIs. I am using Jscape's Sinetfactory. The Telnet I am connecting to sends a prompt to enter 'User name?:' as soon as telnet.connect() occurs. I am required to verify that this prompt is actually happening so I do not just write the answer when something else may happen. I am inexperienced with this and am sure there is a simple answer, just wondering if anyone might be able to help.
这里是我所拥有的，有点草率，因为我已经玩了一段时间了，不确定如何从流中实际读取最后一个字符.
Here is what I have, its a bit sloppy because I've been playing around for awhile not sure how to actually read the last characters from the stream.
import com.jscape.inet.telnet.*;
public class TelnetTest extends TelnetAdapter {
private final static String USER = "xxx\r";
private final static String PWORD = "yyy\r";
private final static String COMMAND = "zzz\r";
private final static byte[] USER_BYTE = USER.getBytes();
private final static byte[] PWORD_BYTE = PWORD.getBytes();
private final static byte[] COMMAND_BYTE = COMMAND.getBytes();
private Telnet telnet = null;
private OutputStream output = null;
private static BufferedReader reader = null;
private boolean connected = false;
private String hostname = "qqq";
//TelnetInputStream tis = null; NOT IN USE AS OF NOW
public TelnetTest() throws IOException, TelnetException {
// create new Telnet instance
telnet = new Telnet(hostname);
// register this class as TelnetListener
telnet.addTelnetListener(this);
// establish Telnet connection
telnet.connect();
connected = true;
output = telnet.getOutputStream();
// HERE IS WHERE I NEED HELP, NOT SURE HOW TO CHECK STREAM
String str = null;
if ((str = reader.readline()).equals("User name?:")) {
telnet.getOutputStream().write(USER_BYTE);
}
// SAME CHECK WOULD HAPPEN HERE FOR "Password"
telnet.getOutputStream().write(PWORD_BYTE);
// ANOTHER SIMILAR CHECK HERE
telnet.getOutputStream().write(COMMAND_BYTE);
// sends all data entered at console to Telnet server
String input = null;
while ((input = reader.readLine()) != null) {
if (connected) {
((TelnetOutputStream) output).println(input);
} else {
break;
}
}
}
public boolean streamContainsString(Reader reader, String searchString)
throws IOException {
Scanner streamScanner = new Scanner(reader);
if (streamScanner.findWithinHorizon(searchString, 0) != null) {
return true;
} else {
return false;
}
}
// Invoked when Telnet socked is connected.
public void connected(TelnetConnectedEvent event) {
System.out.println("Connected");
}
// Invoked when Telnet socket is disconnected. Disconnect can
public void disconnected(TelnetDisconnectedEvent event) {
connected = false;
System.out.print("Disconnected. Press enter key to quit.");
}
// Invoked when Telnet server requests that the Telnet client begin performing specified TelnetOption.
public void doOption(DoOptionEvent event) {
// refuse any options requested by Telnet server
telnet.sendWontOption(event.getOption());
}
// Invoked when Telnet server offers to begin performing specified TelnetOption.
public void willOption(WillOptionEvent event) {
// refuse any options offered by Telnet server
telnet.sendDontOption(event.getOption());
}
// Invoked when data is received from Telnet server.
public void dataReceived(TelnetDataReceivedEvent event) {
// print data recevied from Telnet server to console
System.out.print(event.getData());
}
public Telnet getTelnet() {
return telnet;
}
// starts console program
public static void main(String[] args) {
try {
// create BufferedReader to read data from console
reader = new BufferedReader(new InputStreamReader(System.in));
// create new TelnetExample instance
TelnetTest example = new TelnetTest();
} catch (Exception e) {
e.printStackTrace(System.out);
}
}
}
推荐答案
如果您正在读/写字符串，则应始终使用Reader和Writer. BufferedReader允许您执行行操作.因此，将BufferedReader包裹在Reader(围绕InputStreamReader)周围，将允许您执行readLine()调用以从连接中获取输入行:
If you are reading/writing Strings then you should always use Reader and Writer. BufferedReader allows you to do line operations. So a BufferedReader wrapped around an Reader (around a InputStreamReader) will allow you to do a readLine() call to get the line of input from the connection:
BufferedReader reader =
new BufferedReader(new InputStreamReader(telnet.getInputStream()));
要写入连接，可以在OutputStreamWriter周围使用Writer:
To write to the connection you would use a Writer around a OutputStreamWriter:
Writer writer = new OutputStreamWriter(telnet.getOutputStream()));
我不确定这是否适用于Telnet中的流，但它适用于原始的Socket.然后，您可以执行以下伪代码:
I'm not sure if that works with the stream from Telnet but it works with a raw Socket. You then could do something like the following pseudo code:
while (true) {
read a line from the server
some sort of if/then/else to test for the output
write your username/password or whatever is appropriate for the connection
repeat until some logout or IOException...
}
Apache Telnet类具有许多有趣的侦听器和其他处理程序，您可以根据需要使用这些处理程序，但学习过程可能会更多.这是一个使用TelnetClient的优秀示例应用程序:
The Apache Telnet class has a number of interesting listeners and other handlers which you could use if you wanted to but the learning curve may be more. Here's a good sample application using TelnetClient:
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