Added test case for IIOOutputStreamAdapter + fixed bug in flush method.

Strengthened tests for IIOInputStreamAdapter
Minor clean up of the code.

imageio/imageio-core/src/main/java/com/twelvemonkeys/imageio/util/IIOInputStreamAdapter.java

@@ -28,6 +28,8 @@
 
 package com.twelvemonkeys.imageio.util;
 
+import com.twelvemonkeys.lang.Validate;
+
 import javax.imageio.stream.ImageInputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -75,16 +77,12 @@ class IIOInputStreamAdapter extends InputStream {
     }
 
     private IIOInputStreamAdapter(ImageInputStream pInput, long pLength, boolean pHasLength) {
-        if (pInput == null) {
-            throw new IllegalArgumentException("stream == null");
-        }
-        if (pHasLength && pLength < 0) {
-            throw new IllegalArgumentException("length < 0");
-        }
+        Validate.notNull(pInput, "stream");
+        Validate.isTrue(!pHasLength || pLength >= 0, pLength, "length < 0: %f");
 
         input = pInput;
-        hasLength = pHasLength;
         left = pLength;
+        hasLength = pHasLength;
     }
 
 
@@ -105,6 +103,7 @@ class IIOInputStreamAdapter extends InputStream {
         if (hasLength) {
             return left > 0 ? (int) Math.min(Integer.MAX_VALUE, left) : 0;
         }
+
         return 0; // We don't really know, so we say 0 to be safe.
     }
 

imageio/imageio-core/src/main/java/com/twelvemonkeys/imageio/util/IIOOutputStreamAdapter.java

@@ -28,6 +28,8 @@
 
 package com.twelvemonkeys.imageio.util;
 
+import com.twelvemonkeys.lang.Validate;
+
 import javax.imageio.stream.ImageOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
@@ -43,27 +45,40 @@ class IIOOutputStreamAdapter extends OutputStream {
     private ImageOutputStream output;
 
     public IIOOutputStreamAdapter(final ImageOutputStream pOutput) {
+        Validate.notNull(pOutput, "stream == null");
+
         output = pOutput;
     }
 
     @Override
     public void write(final byte[] pBytes) throws IOException {
+        assertOpen();
         output.write(pBytes);
     }
 
     @Override
     public void write(final byte[] pBytes, final int pOffset, final int pLength) throws IOException {
+        assertOpen();
         output.write(pBytes, pOffset, pLength);
     }
 
     @Override
     public void write(final int pByte) throws IOException {
+        assertOpen();
         output.write(pByte);
     }
 
     @Override
     public void flush() throws IOException {
-        output.flush();
+        // NOTE: The contract of OutputStream.flush is very different from ImageOutputStream.flush. We can't delegate.
+        // TODO: Fulfill the contract of OutputStream.flush? This seems to be good enough for now.
+        assertOpen();
+    }
+
+    private void assertOpen() throws IOException {
+        if (output == null) {
+            throw new IOException("stream already closed");
+        }
     }
 
     @Override

imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/util/IIOInputStreamAdapterTestCase.java

@@ -51,6 +51,11 @@ public class IIOInputStreamAdapterTestCase extends InputStreamAbstractTestCase {
         return new IIOInputStreamAdapter(new MemoryCacheImageInputStream(new ByteArrayInputStream(pBytes)), pBytes.length);
     }
 
+    @Test(expected = IllegalArgumentException.class)
+    public void testCreateNull() {
+        new IIOInputStreamAdapter(null);
+    }
+
     @Test
     public void testReadSubstreamOpenEnd() throws IOException {
         byte[] bytes = new byte[20];

imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/util/IIOOutputStreamAdapterTestCase.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2011, Harald Kuhr
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name "TwelveMonkeys" nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.twelvemonkeys.imageio.util;
+
+import com.twelvemonkeys.io.OutputStreamAbstractTestCase;
+import org.junit.Test;
+
+import javax.imageio.stream.MemoryCacheImageOutputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+import static org.junit.Assert.*;
+
+/**
+ * IIOOutputStreamAdapterTestCase
+ *
+ * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
+ * @author last modified by $Author: haraldk$
+ * @version $Id: IIOOutputStreamAdapterTestCase.java,v 1.0 30.11.11 12:21 haraldk Exp$
+ */
+public class IIOOutputStreamAdapterTestCase extends OutputStreamAbstractTestCase {
+    @Override
+    protected OutputStream makeObject() {
+        return new IIOOutputStreamAdapter(new MemoryCacheImageOutputStream(new ByteArrayOutputStream()));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testCreateNull() {
+        new IIOOutputStreamAdapter(null);
+    }
+
+    @Test
+    public void testFlushOnAdapterDoesNotMoveFlushedPositionInBacking() throws IOException {
+        MemoryCacheImageOutputStream backing = new MemoryCacheImageOutputStream(new ByteArrayOutputStream());
+        IIOOutputStreamAdapter adapter = new IIOOutputStreamAdapter(backing);
+
+        // Sanity check
+        assertEquals(0, backing.getFlushedPosition());
+
+        // Write & flush
+        adapter.write(0xCA);
+        adapter.write(new byte[8]);
+        adapter.write(0xFE);
+        adapter.flush();
+
+        // Assertions
+        assertEquals(10, backing.length());
+        assertEquals(10, backing.getStreamPosition());
+        assertEquals(0, backing.getFlushedPosition());
+
+        // Just make sure we can safely seek back to start and read data back
+        backing.seek(0);
+        assertEquals(0, backing.getStreamPosition());
+
+        // If this can be read, I think the contract of flush is also fulfilled (kind of)
+        assertEquals(0xCA, backing.read());
+        assertEquals(8, backing.skipBytes(8));
+        assertEquals(0xFE, backing.read());
+    }
+}