/** Handshake with the debuggee */
void handshake(Socket s, long timeout) throws IOException {
s.setSoTimeout((int) timeout);
byte[] hello = "JDWP-Handshake".getBytes("UTF-8");
s.getOutputStream().write(hello);
byte[] b = new byte[hello.length];
int received = 0;
while (received < hello.length) {
int n;
try {
n = s.getInputStream().read(b, received, hello.length - received);
} catch (SocketTimeoutException x) {
throw new IOException("handshake timeout");
}
if (n < 0) {
s.close();
throw new IOException("handshake failed - connection prematurally closed");
}
received += n;
}
for (int i = 0; i < hello.length; i++) {
if (b[i] != hello[i]) {
throw new IOException("handshake failed - unrecognized message from target VM");
}
}
// disable read timeout
s.setSoTimeout(0);
}
/** Attach to the specified address with optional attach and handshake timeout. */
public Connection attach(String address, long attachTimeout, long handshakeTimeout)
throws IOException {
if (address == null) {
throw new NullPointerException("address is null");
}
if (attachTimeout < 0 || handshakeTimeout < 0) {
throw new IllegalArgumentException("timeout is negative");
}
int splitIndex = address.indexOf(':');
String host;
String portStr;
if (splitIndex < 0) {
host = InetAddress.getLocalHost().getHostName();
portStr = address;
} else {
host = address.substring(0, splitIndex);
portStr = address.substring(splitIndex + 1);
}
int port;
try {
port = Integer.decode(portStr).intValue();
} catch (NumberFormatException e) {
throw new IllegalArgumentException("unable to parse port number in address");
}
// open TCP connection to VM
InetSocketAddress sa = new InetSocketAddress(host, port);
Socket s = new Socket();
try {
s.connect(sa, (int) attachTimeout);
} catch (SocketTimeoutException exc) {
try {
s.close();
} catch (IOException x) {
}
throw new TransportTimeoutException("timed out trying to establish connection");
}
// handshake with the target VM
try {
handshake(s, handshakeTimeout);
} catch (IOException exc) {
try {
s.close();
} catch (IOException x) {
}
throw exc;
}
return new SocketConnection(s);
}
public void close() throws IOException {
synchronized (closeLock) {
if (closed) {
return;
}
socketOutput.close();
socketInput.close();
socket.close();
closed = true;
}
}
SocketConnection(Socket socket) throws IOException {
this.socket = socket;
socket.setTcpNoDelay(true);
socketInput = socket.getInputStream();
socketOutput = socket.getOutputStream();
}
