If a Java client application is running behind a proxy server, it is not able to connect with Internet services without special measures to get past the proxy. To work with a proxy, the Java client needs to specify information about the proxy itself, as well as user information for authentication on the proxy.

Configuring the proxy is done through a set of system properties in the Java VM:

  • http.proxySet : indicates that a proxy server is used for outgoing connections.

  • http.proxyHost : defines the host name of the proxy server.

  • http.proxyPort : specifies what port the proxy is listening on.

These system properties can be configured programmatically through the java.lang.System class: 

System.getProperties().put("http.proxySet", "true");
System.getProperties().put("http.proxyHost", "proxy.mycompany.com");
System.getProperties().put("http.proxyPort", "8080");

Equivalently, these properties can also be configured through the VM parameters at startup:

java -Dhttp.proxySet=true -Dhttp.proxyHost=proxy.mycompany.com -Dhttp.proxyPort=8080

Authentication

If the proxy requires authentication, you can provide your credentials by using a custom ILcdOWSTransport which sets the Proxy-Authorization HTTP request property. This approach is identical to the approach for connecting to a server which requires authentication. 

ILcdOWSTransport transport = new TLcdOWSHttpTransport() {
  @Override
  protected void configureConnection(URI aURI, ILcdOWSRequest aRequest, HttpURLConnection aConnection) throws IOException {
    super.configureConnection(aURI, aRequest, aConnection);
    String credentials = "username:password";
    String encodedCredentials = Base64.getEncoder().encodeToString(credentials.getBytes());
    aConnection.setRequestProperty("Proxy-Authorization", "Basic " + encodedCredentials);
  }
};