src/com/android/gallery3d/data/DownloadUtils.java

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.gallery3d.data;

import com.android.gallery3d.common.Utils;
import com.android.gallery3d.util.ThreadPool.CancelListener;
import com.android.gallery3d.util.ThreadPool.JobContext;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import java.net.URL;

public class DownloadUtils {
    private static final String TAG = "DownloadService";

    public static boolean requestDownload(JobContext jc, URL url, File file) {
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            return download(jc, url, fos);
        } catch (Throwable t) {
            return false;
        } finally {
            Utils.closeSilently(fos);
        }
    }

    public static void dump(JobContext jc, InputStream is, OutputStream os)
            throws IOException {
        byte buffer[] = new byte[4096];
        int rc = is.read(buffer, 0, buffer.length);
        final Thread thread = Thread.currentThread();
        jc.setCancelListener(new CancelListener() {
            public void onCancel() {
                thread.interrupt();
            }
        });
        while (rc > 0) {
            if (jc.isCancelled()) throw new InterruptedIOException();
            os.write(buffer, 0, rc);
            rc = is.read(buffer, 0, buffer.length);
        }
        jc.setCancelListener(null);
        Thread.interrupted(); // consume the interrupt signal
    }

    public static boolean download(JobContext jc, URL url, OutputStream output) {
        InputStream input = null;
        try {
            input = url.openStream();
            dump(jc, input, output);
            return true;
        } catch (Throwable t) {
            Log.w(TAG, "fail to download", t);
            return false;
        } finally {
            Utils.closeSilently(input);
        }
    }
}