package external; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintStream; import java.nio.ByteBuffer; import java.nio.channels.Channels; import java.nio.channels.Pipe; import java.nio.channels.SelectionKey; import java.nio.channels.Selector; import java.util.ArrayList; import java.util.List; import java.util.logging.Level; import java.util.logging.Logger; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * Provides similar functions as the Unix Expect tool.
* There are two ways to create an Expect object: a constructor that takes an * {@link InputStream} handle and {@link OutputStream} handle; or spawning a * process by providing a comamnd String.
*
* The API is loosely based on Perl Expect library:
* * http://search.cpan.org/~rgiersig/Expect-1.15/Expect.pod * *
* If you are not familiar with the Tcl version of Expect, take a look at:
* * http://oreilly.com/catalog/expect/chapter/ch03.html
*
* Expect uses a thread to convert InputStream to a SelectableChannel; other * than this, no multi-threading is used.
* A call to expect() will block for at most timeout seconds. Expect is not * designed to be thread-safe, in other words, do not call methods of the same * Expect object in different threads. * * @author Ronnie Dong * @version 1.2 (modified from original, https://github.com/ronniedong/Expect-for-Java/blob/master/Expect.java) */ public class Expect { static final Logger log = Logger.getLogger( "expect" ); /**Logging is turned off by default.*/ static { log.setLevel(Level.OFF); } private OutputStream output; private Pipe.SourceChannel inputChannel; private Selector selector; public Expect(InputStream input, OutputStream output) { try { this.inputChannel = inputStreamToSelectableChannel(input); selector = Selector.open(); inputChannel.register(selector, SelectionKey.OP_READ); } catch (IOException e) { log.log( Level.SEVERE, "Fatal error when initializing pipe or selector", e); //e.printStackTrace(); } this.output = output; } /** * Essentially, this method converts an {@link InputStream} to a * {@link SelectableChannel}. A thread is created to read from the * InputStream, and write to a pipe. The source of the pipe is returned as * an input handle from which you can perform unblocking read. The thread * will terminate when reading EOF from InputStream, or when InputStream is * closed, or when the returned Channel is closed(pipe broken). * * @param input * @return a non-blocking Channel you can read from * @throws IOException * most unlikely * */ private static Pipe.SourceChannel inputStreamToSelectableChannel( final InputStream input) throws IOException { Pipe pipe = Pipe.open(); pipe.source().configureBlocking(false); final OutputStream out = Channels.newOutputStream(pipe.sink()); Thread piping = new Thread(new Runnable() { @Override public void run() { //LOG byte[] buffer = new byte[1024]; try { for (int n = 0; n != -1; n = input.read(buffer)) { out.write(buffer, 0, n); if (duplicatedTo != null) { String toWrite = new String(buffer, 0, n); duplicatedTo.append(toWrite); // no Exception will be thrown } } log.fine("EOF from InputStream"); input.close(); // now that input has EOF, close it. // other than this, do not close input } catch (IOException e) { log.log( Level.WARNING, "IOException when piping from InputStream, " + "now the piping thread will end", e); //e.printStackTrace(); } finally { try { log.fine("closing sink of the pipe"); out.close(); } catch (IOException e) { } } } }); piping.setName("Piping InputStream to SelectableChannel Thread"); piping.setDaemon(true); piping.start(); return pipe.source(); } private Process process = null; /** * @return the spawned process, if this {@link Expect} object is created by * spawning a process */ public Process getProcess() { return process; } /** * Creates an Expect object by spawning a command.
* To Linux users, perhaps you need to use "bash -i" if you want to spawn * Bash.
* Note: error stream of the process is redirected to output stream. * * @param command * @return Expect object created using the input and output handles from the * spawned process */ public static Expect spawn(String command) { ProcessBuilder pb = new ProcessBuilder(command.split(" ")); pb.redirectErrorStream(true); Process p; try { p = pb.start(); } catch (IOException e) { //e.printStackTrace(); log.log( Level.WARNING, "Error when spawning command: " + command, e); return null; } Expect retv = new Expect(p.getInputStream(), p.getOutputStream()); retv.process = p; return retv; } /** * @param str * Convenience method to send a string to output handle */ public void send(String str) { this.send(str.getBytes()); } /** * @param toWrite * Write a byte array to the output handle, notice flush() */ public void send(byte[] toWrite) { //System.out.println("sending: " + bytesToPrintableString(toWrite)); log.info("sending: " + bytesToPrintableString(toWrite)); try { output.write(toWrite); output.flush(); } catch (IOException e) { log.log( Level.WARNING, "Error when sending bytes to output", e); //e.printStackTrace(); } } private int default_timeout = 60; private boolean restart_timeout_upon_receive = false; private StringBuffer buffer = new StringBuffer(); private boolean notransfer = false; /**String before the last match(if there was a match), * updated after each expect() call*/ public String before; /**String representing the last match(if there was a match), * updated after each expect() call*/ public String match; /**Whether the last match was successful, * updated after each expect() call*/ public boolean isSuccess = false; public static final int RETV_TIMEOUT = -1, RETV_EOF = -2, RETV_IOEXCEPTION = -9; /** * Convenience method, same as calling {@link #expect(int, Object...) * expect(default_timeout, patterns)} * * @param patterns * @return */ public int expect(Object... patterns) { return expect(default_timeout, patterns); } /** * Convenience method, internally it constructs a List{@literal } * using the object array, and call {@link #expect(int, List) } using the * List. The {@link String}s in the object array will be treated as * literals; meanwhile {@link Pattern}s will be directly added to the List. * If the array contains other objects, they will be converted by * {@link #toString()} and then used as literal strings. * * @param patterns * @return */ public int expect(int timeout, Object... patterns) { ArrayList list = new ArrayList(); for (Object o : patterns) { if (o instanceof String) list.add(Pattern.compile(Pattern.quote((String) o))); // requires 1.5 and up else if (o instanceof Pattern) list.add((Pattern) o); else{ log.warning("Object " + o.toString() + " (class: " + o.getClass().getName() + ") is neither a String nor " + "a java.util.regex.Pattern, using as a literal String"); list.add(Pattern.compile(Pattern.quote(o.toString()))); } } return expect(timeout, list); } /** * Expect will wait for the input handle to produce one of the patterns in * the list. If a match is found, this method returns immediately; * otherwise, the methods waits for up to timeout seconds, then returns. If * timeout is less than or equal to 0 Expect will check one time to see if * the internal buffer contains the pattern. * * @param timeout * timeout in seconds * @param list * List of Java {@link Pattern}s used for match the internal * buffer obtained by reading the InputStream * @return position of the matched pattern within the list (starting from * 0); or a negative number if there is an IOException, EOF or * timeout */ public int expect(int timeout, List list) { log.fine("Expecting " + list); clearGlobalVariables(); long endTime = System.currentTimeMillis() + (long)timeout * 1000; try { ByteBuffer bytes = ByteBuffer.allocate(1024); int n; while (true) { for (int i = 0; i < list.size(); i++) { log.finer("trying to match " + list.get(i) + " against buffer \"" + buffer + "\""); Matcher m = list.get(i).matcher(buffer); if (m.find()) { log.finer("success!"); int matchStart = m.start(), matchEnd = m.end(); this.before = buffer.substring(0, matchStart); this.match = m.group(); this.isSuccess = true; if(!notransfer)buffer.delete(0, matchEnd); return i; } } long waitTime = endTime - System.currentTimeMillis(); if (restart_timeout_upon_receive) waitTime = timeout * 1000; if (waitTime <= 0) { log.fine("Timeout when expecting " + list); return RETV_TIMEOUT; } //System.out.println("waiting for "+waitTime); selector.select(waitTime); //System.out.println(selector.selectedKeys().size()); if (selector.selectedKeys().size() == 0) { //System.err.println("timeout!"); //break; //we can directly "break" here log.fine("Timeout when expecting " + list); return RETV_TIMEOUT; } selector.selectedKeys().clear(); if ((n = inputChannel.read(bytes)) == -1) { //System.err.println("EOF!"); //break; log.fine("EOF when expecting " + list); return RETV_EOF; } log.log(Level.FINEST, "read bytes: {0}", n); StringBuilder tmp = new StringBuilder(); for (int i = 0; i < n; i++) { buffer.append((char) bytes.get(i)); tmp.append(byteToPrintableString(bytes.get(i))); } log.fine("Obtained following from InputStream: " + tmp); bytes.clear(); //System.out.println(buffer); } } catch (IOException e) { //e.printStackTrace(); log.log( Level.WARNING, "IOException when selecting or reading", e); thrownIOE = e; return RETV_IOEXCEPTION; } } /** * Convenience method, internally it calls {@link #expect(int, List) * expect(timeout, new ArrayList<Pattern>())}. Given an empty list, * {@link #expect(int, List)} will not perform any regex matching, therefore * the only conditions for it to return is EOF or timeout (or IOException). * If EOF is detected, {@link #isSuccess} and {@link #before} are properly * set. * * @param timeout * @return same as return value of {@link #expect(int, List)} */ public int expectEOF(int timeout) { int retv = expect(timeout, new ArrayList()); if (retv == RETV_EOF) { this.isSuccess = true; this.before = this.buffer.toString(); this.buffer.delete(0, buffer.length()); } return retv; } /**Convenience method, same as calling {@link #expectEOF(int) * expectEOF(default_timeout)}*/ public int expectEOF() { return expectEOF(default_timeout); } /** * Throws checked exceptions when expectEOF was not successful. */ public int expectEOFOrThrow(int timeout) throws TimeoutException, IOException { int retv = expectEOF(timeout); if (retv == RETV_TIMEOUT) throw new TimeoutException(); if (retv == RETV_IOEXCEPTION) throw thrownIOE; return retv; } /**Convenience method, same as calling {@link #expectEOF(int) * expectEOF(default_timeout)}*/ public int expectEOFOrThrow() throws TimeoutException, IOException { return expectEOFOrThrow(default_timeout); } /**useful when calling {@link #expectOrThrow(int, Object...)}*/ private IOException thrownIOE; /** * This method calls {@link #expect(int, Object...) expect(timeout, * patterns)}, and throws checked exceptions when expect was not successful. * Useful when you want to simplify error handling: for example, when you * send a series of commands to an SSH server, you expect a prompt after * each send, however the server may die or the prompt may take forever to * appear, you would want to skip the following commands if those occurred. * In such a case this method will be handy. * * @param timeout * @param patterns * @throws TimeoutException * when expect times out * @throws EOFException * when EOF is encountered * @throws IOException * when there is a problem reading from the InputStream * @return same as {@link #expect(int, Object...) expect(timeout, patterns)} */ public int expectOrThrow(int timeout, Object... patterns) throws TimeoutException, EOFException, IOException { int retv = expect(timeout, patterns); switch (retv) { case RETV_TIMEOUT: throw new TimeoutException(); case RETV_EOF: throw new EOFException(); case RETV_IOEXCEPTION: throw thrownIOE; default: return retv; } } /**Convenience method, same as calling {@link #expectOrThrow(int, Object...) * expectOrThrow(default_timeout, patterns)}*/ public int expectOrThrow(Object... patterns) throws TimeoutException, EOFException, IOException { return expectOrThrow(default_timeout, patterns); } private void clearGlobalVariables() { isSuccess = false; match = null; before = null; } /** * The OutputStream passed to Expect constructor is closed; the InputStream * is not closed (there is no need to close the InputStream).
* It is suggested that this method be called after the InputStream has come * to EOF. For example, when you connect through SSH, send an "exit" command * first, and then call this method.
*
* * When this method is called, the thread which write to the sink of the * pipe will end. */ public void close() { try { this.output.close(); } catch (IOException e) { log.log( Level.WARNING, "Exception when closing OutputStream", e); //e.printStackTrace(); } try { this.inputChannel.close(); } catch (IOException e) { log.log( Level.WARNING, "Exception when closing input Channel", e); //e.printStackTrace(); } } public int getDefault_timeout() { return default_timeout; } public void setDefault_timeout(int default_timeout) { this.default_timeout = default_timeout; } public boolean isRestart_timeout_upon_receive() { return restart_timeout_upon_receive; } public void setRestart_timeout_upon_receive(boolean restart_timeout_upon_receive) { this.restart_timeout_upon_receive = restart_timeout_upon_receive; } public void setNotransfer(boolean notransfer) { this.notransfer = notransfer; } public boolean isNotransfer() { return notransfer; } /** * Static method used for convert byte array to string, each byte is * converted to an ASCII character, if the byte represents a control * character, it is replaced by a printable caret notation * http://en.wikipedia.org/wiki/ASCII , or an escape code if possible. * * @param bytes * bytes to be printed * @return String representation of the byte array */ public static String bytesToPrintableString(byte[] bytes) { StringBuilder sb = new StringBuilder(); for (byte b : bytes) sb.append(byteToPrintableString(b)); return sb.toString(); } public static String byteToPrintableString(byte b) { String s = new String(new byte[] { b }); // control characters if (b >= 0 && b < 32) s = "^" + (char) (b + 64); else if (b == 127) s = "^?"; // some escape characters if (b == 9) s = "\\t"; if (b == 10) s = "\\n"; if (b == 13) s = "\\r"; return s; } @SuppressWarnings("serial") public static class TimeoutException extends Exception{ } @SuppressWarnings("serial") public static class EOFException extends Exception{ } private static PrintStream duplicatedTo = null; /** * While performing expect operations on the InputStream provided, duplicate * the contents obtained from InputStream to a PrintStream (you can use * System.err or System.out). DO NOT call this function while there * are live Expect objects as this may cause the piping thread to end due to * unsynchronized code; if you need this feature, add the following to both * {@link #inputStreamToSelectableChannel(InputStream)} and * {@link #forwardInputStreamTo(PrintStream)}: *
	 * {@code
	 * 	synchronized(Expect.duplicatedTo) {...}
	 * 
* @param duplicatedTo * call with null if you want to turn off */ public static void forwardInputStreamTo(PrintStream duplicatedTo) { Expect.duplicatedTo = duplicatedTo; } }