How can I specify the local address on a java.net.URLConnection?

Question

My Tomcat instance is listening to multiple IP addresses, but I want to control which source IP address is used when opening a URLConnection.

How can I

Answer 1

Using the Apache commons HttpClient I have also found the following to work (removed try/catch for clarity):

HostConfiguration hostConfiguration = new HostConfiguration();
byte b[] = new byte[4];
b[0] = new Integer(192).byteValue();
b[1] = new Integer(168).byteValue();
b[2] = new Integer(1).byteValue();
b[3] = new Integer(11).byteValue();

hostConfiguration.setLocalAddress(InetAddress.getByAddress(b));

HttpClient client = new HttpClient();
client.setHostConfiguration(hostConfiguration);
GetMethod method = new GetMethod("http://remoteserver/");
method.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
    new DefaultHttpMethodRetryHandler(3, false));
int statusCode = client.executeMethod(method);

if (statusCode != HttpStatus.SC_OK) {
    System.err.println("Method failed: " + method.getStatusLine());
}

byte[] responseBody = method.getResponseBody();
System.out.println(new String(responseBody));");

However, I still wonder what would happen if the gateway of the IP is down (192.168.1.11 in this case). Will the next gateway be tried or will it fail?