Using Java to access a URL through a proxy

The following code snippet demonstrates how to access a URL through a proxy that requires authentication:

public static String connectToProxy() {

     String result = "";
     String status = "";

     Authenticator.setDefault(new ProxyAuthenticator(username, password));
     System.setProperty("http.proxyHost", PROXY_HOST);  
     System.setProperty("http.proxyPort", PROXY_PORT); 
    
     try {
          URL url;
          url = new URL("http://google.com");
          HttpURLConnection con = (HttpURLConnection) url.openConnection();
          BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
          while ((result = in.readLine()) != null)
               status += result;
          in.close();
     }
     catch (MalformedURLException e) {
          e.printStackTrace();
     }
     catch (IOException e) {
         e.printStackTrace();
     }
     return status;
}

class ProxyAuthenticator extends Authenticator {
     private String user, password;

     public ProxyAuthenticator(String user, String password) {  
          this.user = user;
          this.password = password;  
     }  
  
     protected PasswordAuthentication getPasswordAuthentication() {  
          return new PasswordAuthentication(user, password.toCharArray());  
     }
} 

Using Java to Call RESTful web services

The following code snippet demonstrates how to call a RESTful web service that requires BASIC Authentication:

public static String connectToResource() {

     String result = "";
     String status = "";

     try {
         URL url = new URL("http://localhost:8080/WEB_APP/RESOURCE/PRODUCT_ID");
         HttpURLConnection connection = (HttpURLConnection) url.openConnection();
         connection.setRequestProperty("Authorization", "Basic " + 
              new String(com.sun.jersey.core.util.Base64.encode(username + ":" + password)));
         connection.setRequestMethod("GET");
         BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
         while ((result = in.readLine()) != null)
              status += result;
         in.close();
     }
     catch (MalformedURLException e) {
          e.printStackTrace();
     }
     catch (IOException e) {
          e.printStackTrace();
     }
     return status;
}