Bugzilla #36082

Renamed FOUserAgent.getStream() to FOUserAgent.resolveURI() which now simply returns a Source instance which the ImageFactory uses to get at an InputStream somehow.
Submitted by: Manuel Mall <mm.at.arcus.com.au>

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@232949 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -33,31 +33,34 @@ import org.apache.commons.logging.LogFactory;
  * @see javax.xml.transform.URIResolver
  */
 public class FOURIResolver
-    implements javax.xml.transform.URIResolver
-{
+    implements javax.xml.transform.URIResolver {
+    
     private Log log = LogFactory.getLog("FOP");
     
     /**
-     * Called by the processor through {@link FOUserAgent} when it encounters an uri in an external-graphic element.
+     * Called by the processor through {@link FOUserAgent} when it encounters an 
+     * uri in an external-graphic element.
      * (see also {@link javax.xml.transform.URIResolver#resolve(String, String)}
-     * This resolver will allow URLs without a scheme, i.e. it assumes 'file:' as the default
-     * scheme. It also allows relative URLs with scheme, e.g. file:../../abc.jpg which is
-     * not strictly RFC compliant as long as the scheme is the same as the scheme of the
-     * base URL. If the base URL is null a 'file:' URL referencing the current directory is used as 
-     * the base URL.
+     * This resolver will allow URLs without a scheme, i.e. it assumes 'file:' as
+     * the default scheme. It also allows relative URLs with scheme, 
+     * e.g. file:../../abc.jpg which is not strictly RFC compliant as long as the 
+     * scheme is the same as the scheme of the base URL. If the base URL is null 
+     * a 'file:' URL referencing the current directory is used as the base URL.
      * If the method is successful it will return a Source of type 
-     * {@link javax.xml.transform.stream.StreamSource} with its SystemID set to the resolved
-     * URL used to open the underlying InputStream.
+     * {@link javax.xml.transform.stream.StreamSource} with its SystemID set to 
+     * the resolved URL used to open the underlying InputStream.
      * 
      * @param href An href attribute, which may be relative or absolute.
-     * @param base The base URI against which the first argument will be made absolute if the absolute URI is required. 
-     * @return A {@link javax.xml.transform.Source} object, or null if the href cannot be resolved. 
-     * @throws TransformerException Never thrown by this implementation.
+     * @param base The base URI against which the first argument will be made 
+     * absolute if the absolute URI is required. 
+     * @return A {@link javax.xml.transform.Source} object, or null if the href 
+     * cannot be resolved. 
+     * @throws javax.xml.transform.TransformerException Never thrown by this implementation.
      * @see javax.xml.transform.URIResolver#resolve(String, String)
      */
     public Source resolve(String href, String base)
-        throws javax.xml.transform.TransformerException
-    {
+        throws javax.xml.transform.TransformerException {
+        
         URL absoluteURL = null;
         URL baseURL = toBaseURL(base);
         if (baseURL == null) {
@@ -120,8 +123,7 @@ public class FOURIResolver
      * @param baseURL the base URL
      * @returns the base URL as java.net.URL
      */
-    private URL toBaseURL(String baseURL)
-    {
+    private URL toBaseURL(String baseURL) {
         try {
             return new URL(baseURL == null 
                             ? new java.io.File("").toURL().toExternalForm() 

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

@@ -20,14 +20,12 @@ package org.apache.fop.apps;
 
 // Java
 import java.io.File;
-import java.io.IOException;
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
 import javax.xml.transform.Source;
 import javax.xml.transform.TransformerException;
 import javax.xml.transform.URIResolver;
-import javax.xml.transform.stream.StreamSource;
 
 // avalon configuration
 import org.apache.avalon.framework.configuration.Configuration;
@@ -409,7 +407,7 @@ public class FOUserAgent {
      * @return the URI Resolver
      */
     public URIResolver getURIResolver() {
-        return this.uriResolver != null ? this.uriResolver : this.foURIResolver;
+        return this.uriResolver;
     }
 
     /**
@@ -431,29 +429,33 @@ public class FOUserAgent {
 
 
     /**
-     * Get a stream source for a reference. Subclass FOUserAgent and override this method to
-     * do custom URI to {@link javax.xml.transform.stream.StreamSource} resolution.
-     * Alternatively set your own {@link javax.xml.transform.URIResolver} on the FOUserAgent.
-     * Temporary solution until the API is better.
+     * Attempts to resolve the given URI.
+     * Will use the configured resolver and if not successful fall back
+     * to the default resolver.
      * @param uri URI to access
-     * @return StreamSource for accessing the resource.
-     * @throws IOException in case of an I/O problem
+     * @return A {@link javax.xml.transform.Source} object, or null if the URI
+     * cannot be resolved. 
+     * @see org.apache.fop.apps.FOURIResolver
      */
-    public StreamSource getStream(String uri) throws IOException {
+    public Source resolveURI(String uri) {
         Source source = null;
-        try {
-            source = getURIResolver().resolve(uri, getBaseURL());
-        } catch (TransformerException te) {
-            log.error("Attempt to resolve URI '" + uri + "' failed: ", te);
+        URIResolver uriResolver = getURIResolver();
+        if (uriResolver != null) {
+            try {
+                source = uriResolver.resolve(uri, getBaseURL());
+            } catch (TransformerException te) {
+                log.error("Attempt to resolve URI '" + uri + "' failed: ", te);
+            }
         }
-        if (source != null) {
-            if (source instanceof StreamSource) {
-                return (StreamSource)source;
-            } else {
-                log.error("Attempt to resolve URI returned unknown source");
+        if (source == null) {
+            // URI Resolver not configured or returned null, use default resolver
+            try {
+                source = foURIResolver.resolve(uri, getBaseURL());
+            } catch (TransformerException te) {
+                log.error("Attempt to resolve URI '" + uri + "' failed: ", te);
             }
         }
-        return null;
+        return source;
     }
 
     /**

src/java/org/apache/fop/image/ImageFactory.java

@@ -19,7 +19,6 @@
 package org.apache.fop.image;
 
 // Java
-import java.io.IOException;
 import java.io.InputStream;
 import java.lang.reflect.Constructor;
 import java.util.ArrayList;
@@ -29,6 +28,7 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
+import javax.xml.transform.Source;
 import javax.xml.transform.stream.StreamSource;
 
 import org.apache.commons.logging.Log;
@@ -196,12 +196,28 @@ public final class ImageFactory {
      */
     public FopImage loadImage(String href, FOUserAgent ua) {
 
-        StreamSource source = openStream(href, ua);
+        Source source = ua.resolveURI(href);
         if (source == null) {
             return null;
         }
+        
+        // Got a valid source, obtain an InputStream from it
+        InputStream in = null;
+        if (source instanceof StreamSource) {
+            in = ((StreamSource)source).getInputStream();
+        }
+        if (in == null) {
+            try {
+                in = new java.net.URL(source.getSystemId()).openStream();
+            } catch (Exception ex) {
+                log.error("Unable to obtain stream from id '" 
+                    + source.getSystemId() + "'");
+            }
+        }
+        if (in == null) {
+            return null;
+        }
 
-        InputStream in = source.getInputStream();
         //Make sure the InputStream is decorated with a BufferedInputStream
         if (!(in instanceof java.io.BufferedInputStream)) {
             in = new java.io.BufferedInputStream(in);
@@ -277,26 +293,6 @@ public final class ImageFactory {
         return (FopImage) imageInstance;
     }
 
-    /**
-     * Create a StreamSource objects.
-     * @param href image URL as a String
-     * @param ua user agent
-     * @return a new StreamSource object
-     */
-    protected StreamSource openStream(String href, FOUserAgent ua) {
-
-        StreamSource in = null;
-
-        try {
-            in = ua.getStream(href);
-        } catch (IOException ioe) {
-            log.error("Error while opening stream for ("
-                    + href + "): " + ioe.getMessage(), ioe);
-            return null;
-        }
-        return in;
-    }
-
     private Class getImageClass(String imgMimeType) {
         ImageMimeType imt = (ImageMimeType)imageMimeTypes.get(imgMimeType);
         if (imt == null) {

test/java/org/apache/fop/URIResolutionTestCase.java

@@ -19,7 +19,6 @@
 package org.apache.fop;
 
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.io.OutputStream;
 
 import javax.xml.transform.Result;
@@ -75,8 +74,10 @@ public class URIResolutionTestCase extends AbstractFOPTestCase {
         Document doc = createAreaTree(foFile, ua);
         
         //Check how many times the resolver was consulted
-        assertEquals(1, resolver.successCount);
-        assertEquals(0, resolver.failureCount);
+        assertEquals("Expected resolver to do 1 successful URI resolution",
+                1, resolver.successCount);
+        assertEquals("Expected resolver to do 0 failed URI resolution",
+                0, resolver.failureCount);
         //Additional XPath checking on the area tree
         assertEquals("viewport for external-graphic is missing", 
                 "true", evalXPath(doc, "boolean(//flow/block[1]/lineArea/viewport)"));
@@ -89,6 +90,7 @@ public class URIResolutionTestCase extends AbstractFOPTestCase {
      * @throws Exception if anything fails
      */
     public void testFO2() throws Exception {
+        //TODO This will only work when we can do URI resolution inside Batik!
         File foFile = new File(getBaseDir(), "test/xml/uri-resolution2.fo");
         
         FOUserAgent ua = new FOUserAgent();
@@ -115,8 +117,10 @@ public class URIResolutionTestCase extends AbstractFOPTestCase {
         }
         
         //Check how many times the resolver was consulted
-        assertEquals(1, resolver.successCount);
-        assertEquals(0, resolver.failureCount);
+        assertEquals("Expected resolver to do 1 successful URI resolution",
+                1, resolver.successCount);
+        assertEquals("Expected resolver to do 0 failed URI resolutions",
+                0, resolver.failureCount);
         //Test using PDF as the area tree doesn't invoke Batik so we could check
         //if the resolver is actually passed to Batik by FOP
         assertTrue("Generated PDF has zero length", baout.size() > 0);
@@ -185,12 +189,6 @@ public class URIResolutionTestCase extends AbstractFOPTestCase {
                 if ("myimage123".equals(name)) {
                     File image = new File(getBaseDir(), "test/resources/images/bgimg300dpi.jpg");
                     StreamSource src = new StreamSource(image);
-                    try {
-                        //TODO The next line should not be necessary!!!
-                        src.setInputStream(new java.io.FileInputStream(image));
-                    } catch (FileNotFoundException e) {
-                        throw new TransformerException(e.getMessage(), e);
-                    }
                     successCount++;
                     return src;
                 } else {