Changed the way the URL stream is opened. Use URLConnection now.

Added an empty protected method that can be overridden to set parameters like HTTP Basic Authentication on the URLConnection.
Convenience method added for handling HTTP Basic Authentication.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@380092 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/fop/apps/FOURIResolver.java

@@ -19,9 +19,13 @@
 package org.apache.fop.apps;
 
 import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.net.URLConnection;
+
 import javax.xml.transform.Source;
 import javax.xml.transform.stream.StreamSource;
 
@@ -30,7 +34,9 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 // base64 support for "data" urls
+// TODO Move Base64 support from Batik to XML Graphics Commons
 import org.apache.batik.util.Base64DecodeStream;
+import org.apache.batik.util.Base64EncoderStream;
 
 /**
  * Provides FOP specific URI resolution.
@@ -95,7 +101,8 @@ public class FOURIResolver
             } else {
                 try {
                     /*
-                        This piece of code is based on the following statement in RFC2396 section 5.2:
+                        This piece of code is based on the following statement in 
+                        RFC2396 section 5.2:
 
                         3) If the scheme component is defined, indicating that the reference
                            starts with a scheme name, then the reference is interpreted as an
@@ -133,13 +140,53 @@ public class FOURIResolver
         }
         
         try {
-            return new StreamSource(absoluteURL.openStream(), absoluteURL.toExternalForm());
+            String effURL = absoluteURL.toExternalForm();
+            URLConnection connection = absoluteURL.openConnection();
+            connection.setAllowUserInteraction(false);
+            connection.setDoInput(true);
+            updateURLConnection(connection, href);
+            connection.connect();
+            return new StreamSource(connection.getInputStream(), effURL);
         } catch (java.io.IOException ioe) {
             log.error("Error with opening URL '" + href + "': " + ioe.getMessage(), ioe);
         }
         return null;
     }
 
+    /**
+     * This method allows you to set special values on a URLConnection just before the connect()
+     * method is called. Subclass FOURIResolver and override this method to do things like
+     * adding the user name and password for HTTP basic authentication.
+     * @param connection the URLConnection instance
+     * @param href the original URI
+     */
+    protected void updateURLConnection(URLConnection connection, String href) {
+        //nop
+    }
+    
+    /**
+     * This is a convenience method for users who want to override updateURLConnection for
+     * HTTP basic authentication. Simply call it using the right username and password.
+     * @param connection the URLConnection to set up for HTTP basic authentication
+     * @param username the username
+     * @param password the password
+     */
+    protected void applyHttpBasicAuthentication(URLConnection connection, 
+            String username, String password) {
+        String combined = username + ":" + password;
+        try {
+            ByteArrayOutputStream baout = new ByteArrayOutputStream(combined.length() * 2);
+            Base64EncoderStream base64 = new Base64EncoderStream(baout);
+            base64.write(combined.getBytes());
+            base64.close();
+            connection.setRequestProperty("Authorization", 
+                    "Basic " + new String(baout.toByteArray()));
+        } catch (IOException e) {
+            //won't happen. We're operating in-memory.
+            throw new RuntimeException("Error during base64 encodation of username/password");
+        }
+    }
+    
     /**
      * Returns the base URL as a java.net.URL.
      * If the base URL is not set a default URL pointing to the