Use the Android-provided API to stream-decode base64-encoded data

4 files changed, 72 insertions, 20 deletions

diff --git a/main/src/cgeo/geocaching/network/HtmlImage.java b/main/src/cgeo/geocaching/network/HtmlImage.java
index bde85ee..8ee2ba7 100644
--- a/main/src/cgeo/geocaching/network/HtmlImage.java
+++ b/main/src/cgeo/geocaching/network/HtmlImage.java
@@ -13,7 +13,6 @@ import cgeo.geocaching.utils.Log;
 import cgeo.geocaching.utils.RxUtils;
 
 import ch.boye.httpclientandroidlib.HttpResponse;
-import ch.boye.httpclientandroidlib.androidextra.Base64;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.tuple.ImmutablePair;
@@ -43,9 +42,6 @@ import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.OutputStream;
 import java.util.Date;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ThreadPoolExecutor;
@@ -172,14 +168,15 @@ public class HtmlImage implements Html.ImageGetter {
                 return new ImmutablePair<BitmapDrawable, Boolean>(bitmap != null ?
                         ImageUtils.scaleBitmapToFitDisplay(bitmap) :
                         null,
-                        loadResult.getRight());
+                        loadResult.getRight()
+                );
             }
 
             private void downloadAndSave(final Subscriber<? super BitmapDrawable> subscriber) {
                 final File file = LocalStorage.getStorageFile(pseudoGeocode, url, true, true);
                 if (url.startsWith("data:image/")) {
                     if (url.contains(";base64,")) {
-                        saveBase64ToFile(url, file);
+                        ImageUtils.decodeBase64ToFile(StringUtils.substringAfter(url, ";base64,"), file);
                     } else {
                         Log.e("HtmlImage.getDrawable: unable to decode non-base64 inline image");
                         subscriber.onCompleted();
@@ -254,20 +251,6 @@ public class HtmlImage implements Html.ImageGetter {
         return false;
     }
 
-    private static void saveBase64ToFile(final String url, final File file) {
-        // TODO: when we use SDK level 8 or above, we can use the streaming version of the base64
-        // Android utilities.
-        OutputStream out = null;
-        try {
-            out = new FileOutputStream(file);
-            out.write(Base64.decode(StringUtils.substringAfter(url, ";base64,"), Base64.DEFAULT));
-        } catch (final IOException e) {
-            Log.e("HtmlImage.saveBase64ToFile: cannot write file for decoded inline image", e);
-        } finally {
-            IOUtils.closeQuietly(out);
-        }
-    }
-
     /**
      * Make a fresh copy of the file to reset its timestamp. On some storage, it is impossible
      * to modify the modified time after the fact, in which case a brand new file must be
diff --git a/main/src/cgeo/geocaching/utils/ImageUtils.java b/main/src/cgeo/geocaching/utils/ImageUtils.java
index aae0f14..6d7a437 100644
--- a/main/src/cgeo/geocaching/utils/ImageUtils.java
+++ b/main/src/cgeo/geocaching/utils/ImageUtils.java
@@ -3,6 +3,7 @@ package cgeo.geocaching.utils;
 import cgeo.geocaching.CgeoApplication;
 import cgeo.geocaching.compatibility.Compatibility;
 
+import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
@@ -16,11 +17,15 @@ import android.graphics.drawable.BitmapDrawable;
 import android.media.ExifInterface;
 import android.net.Uri;
 import android.os.Environment;
+import android.util.Base64;
+import android.util.Base64InputStream;
 
 import java.io.BufferedOutputStream;
+import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Locale;
@@ -245,4 +250,38 @@ public final class ImageUtils {
         }
         return false;
     }
+
+    /**
+     * Decode a base64-encoded string and save the result into a file.
+     *
+     * @param inString the encoded string
+     * @param outFile the file to save the decoded result into
+     */
+    public static void decodeBase64ToFile(final String inString, final File outFile) {
+        FileOutputStream out = null;
+        try {
+            out = new FileOutputStream(outFile);
+            decodeBase64ToStream(inString, out);
+        } catch (final IOException e) {
+            Log.e("HtmlImage.decodeBase64ToFile: cannot write file for decoded inline image", e);
+        } finally {
+            IOUtils.closeQuietly(out);
+        }
+    }
+
+    /**
+     * Decode a base64-encoded string and save the result into a stream.
+     *
+     * @param inString the encoded string
+     * @param outFile the file to save the decoded result into
+     */
+    public static void decodeBase64ToStream(final String inString, final OutputStream out) throws IOException {
+        Base64InputStream in = null;
+        try {
+            in = new Base64InputStream(new ByteArrayInputStream(inString.getBytes()), Base64.DEFAULT);
+            IOUtils.copy(in, out);
+        } finally {
+            IOUtils.closeQuietly(in);
+        }
+    }
 }
diff --git a/tests/res/raw/small_file.bin b/tests/res/raw/small_file.bin
new file mode 100644
index 0000000..df5b053
--- /dev/null
+++ b/tests/res/raw/small_file.bin
diff --git a/tests/src/cgeo/geocaching/ImageUtilsTest.java b/tests/src/cgeo/geocaching/ImageUtilsTest.java
new file mode 100644
index 0000000..c67d340
--- /dev/null
+++ b/tests/src/cgeo/geocaching/ImageUtilsTest.java
@@ -0,0 +1,30 @@
+package cgeo.geocaching;
+
+import cgeo.geocaching.test.AbstractResourceInstrumentationTestCase;
+import cgeo.geocaching.test.R;
+import cgeo.geocaching.utils.ImageUtils;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Arrays;
+
+public class ImageUtilsTest extends AbstractResourceInstrumentationTestCase {
+
+    private static final String icon64 = "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";
+
+    public void testBase64decoding() throws IOException {
+        final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        ImageUtils.decodeBase64ToStream(icon64, outputStream);
+        final byte[] decodedImage = outputStream.toByteArray();
+        outputStream.close();
+        assertEquals("decoded image has the right size", 409, decodedImage.length);
+        final InputStream originalStream = getResourceStream(R.raw.small_file);
+        final byte[] originalImage = new byte[409];
+        assertEquals("original image has the right size (consistency check)", 409, originalStream.read(originalImage));
+        originalStream.close();
+        assertTrue("decoded base64 image is similar to original file data",
+                Arrays.equals(originalImage, decodedImage));
+    }
+
+}