New stream SPIs now behave more like the built-in SPIs.

imageio/imageio-core/src/main/java/com/twelvemonkeys/imageio/stream/BufferedFileImageInputStream.java

@@ -76,9 +76,8 @@ public final class BufferedFileImageInputStream extends ImageInputStreamImpl {
      * @throws IllegalArgumentException if <code>file</code> is <code>null</code>.
      * @throws FileNotFoundException    if <code>file</code> is a directory or cannot be opened for reading
      *                                  for any reason.
-     * @throws IOException              if an I/O error occurs.
      */
-    public BufferedFileImageInputStream(final File file) throws IOException {
+    public BufferedFileImageInputStream(final File file) throws FileNotFoundException {
         this(new RandomAccessFile(notNull(file, "file"), "r"));
     }
 

imageio/imageio-core/src/main/java/com/twelvemonkeys/imageio/stream/BufferedFileImageInputStreamSpi.java

@@ -36,7 +36,7 @@ import javax.imageio.spi.ImageInputStreamSpi;
 import javax.imageio.spi.ServiceRegistry;
 import javax.imageio.stream.ImageInputStream;
 import java.io.File;
-import java.io.IOException;
+import java.io.FileNotFoundException;
 import java.util.Iterator;
 import java.util.Locale;
 
@@ -69,16 +69,23 @@ public class BufferedFileImageInputStreamSpi extends ImageInputStreamSpi {
         }
     }
 
-    public ImageInputStream createInputStreamInstance(final Object input, final boolean pUseCache, final File pCacheDir) throws IOException {
+    public ImageInputStream createInputStreamInstance(final Object input, final boolean pUseCache, final File pCacheDir) {
         if (input instanceof File) {
-            File file = (File) input;
-            return new BufferedFileImageInputStream(file);
+            try {
+                return new BufferedFileImageInputStream((File) input);
             }
-        else {
-            throw new IllegalArgumentException("Expected input of type URL: " + input);
+            catch (FileNotFoundException e) {
+                // For consistency with the JRE bundled SPIs, we'll return null here,
+                // even though the spec does not say that's allowed.
+                // The problem is that the SPIs can only declare that they support an input type like a File,
+                // instead they should be allowed to inspect the instance, to see that the file does exist...
+                return null;
             }
         }
 
+        throw new IllegalArgumentException("Expected input of type File: " + input);
+    }
+
     @Override
     public boolean canUseCacheFile() {
         return false;

imageio/imageio-core/src/main/java/com/twelvemonkeys/imageio/stream/BufferedRAFImageInputStreamSpi.java

@@ -71,12 +71,10 @@ public class BufferedRAFImageInputStreamSpi extends ImageInputStreamSpi {
 
     public ImageInputStream createInputStreamInstance(final Object input, final boolean pUseCache, final File pCacheDir) {
         if (input instanceof RandomAccessFile) {
-            RandomAccessFile file = (RandomAccessFile) input;
-            return new BufferedFileImageInputStream(file);
-        }
-        else {
-            throw new IllegalArgumentException("Expected input of type URL: " + input);
+            return new BufferedFileImageInputStream((RandomAccessFile) input);
         }
+
+        throw new IllegalArgumentException("Expected input of type RandomAccessFile: " + input);
     }
 
     @Override

imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/stream/BufferedFileImageInputStreamSpiTest.java

@@ -1,9 +1,14 @@
 package com.twelvemonkeys.imageio.stream;
 
+import org.junit.Test;
+
 import javax.imageio.spi.ImageInputStreamSpi;
 import java.io.File;
 import java.io.IOException;
 
+import static org.junit.Assert.assertNull;
+import static org.junit.Assume.assumeFalse;
+
 public class BufferedFileImageInputStreamSpiTest extends ImageInputStreamSpiTest<File> {
     @Override
     protected ImageInputStreamSpi createProvider() {
@@ -14,4 +19,12 @@ public class BufferedFileImageInputStreamSpiTest extends ImageInputStreamSpiTest
     protected File createInput() throws IOException {
         return File.createTempFile("test-", ".tst");
     }
+
+    @Test
+    public void testReturnNullWhenFileDoesNotExist() throws IOException {
+        // This is really stupid behavior, but it is consistent with the JRE bundled SPIs.
+        File input = new File("a-file-that-should-not-exist-ever.fnf");
+        assumeFalse("File should not exist: " + input.getPath(), input.exists());
+        assertNull(provider.createInputStreamInstance(input));
+    }
 }

imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/stream/ImageInputStreamSpiTest.java

@@ -11,10 +11,10 @@ import java.util.Locale;
 import static org.junit.Assert.*;
 
 abstract class ImageInputStreamSpiTest<T> {
-    private final ImageInputStreamSpi provider = createProvider();
+    protected final ImageInputStreamSpi provider = createProvider();
 
     @SuppressWarnings("unchecked")
-    private final Class<T> inputClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
+    protected final Class<T> inputClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
 
     protected abstract ImageInputStreamSpi createProvider();