音乐、视频、apk、图片缩略图提取

ThumbnailExtractor.java

/**
 * 提取文件缩略图,指定缩略图大小, 如果没有指定context，将不会取到apk文件的缩略图
 * 
 * @param file
 * @param width
 * @param height
 * @return
 */
public static Bitmap extractFileThumbnail(File file, int width, int height,
        Context context) {
    int type = getFileType(file);
    Bitmap thumb = null;
    switch (type) {
        case FILE_TYPE_IMAGE:// 获取图像文件缩略图
            thumb = getImageFileThumbnail(file, width, height);
            break;
        case FILE_TYPE_VIDEO:// 获取视频文件缩略图
            thumb = getVideoFileThumbnail(file, width, height);
            break;
        case FILE_TYPE_AUDIO:// 获取音乐文件缩略图，
            if (getFileSuffix(file).toLowerCase().equals("mp3")) {
                Bitmap tmp = getMP3Thumbnail(file);
                thumb = ThumbnailUtils.extractThumbnail(tmp, width, height);
            }
            break;
        case FILE_TYPE_APK:// 获取apk文件按指定尺寸缩放过的缩略图，
            thumb = getApkResizedIcon(context, file.getAbsolutePath(), width,
                    height);
            break;

        default:
            break;
    }
    return thumb;
}

/**
 * 获取图片文件的缩略图
 * 
 * @param file
 * @param width
 * @param height
 * @return
 */
public static Bitmap getImageFileThumbnail(File file, int width, int height) {
    Bitmap bitmap = null;
    String path = file.getAbsolutePath();
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    // 只获取这个图片的宽和高
    bitmap = BitmapFactory.decodeFile(path, options);
    options.inJustDecodeBounds = false;
    // 计算缩放比,出现错误的时候有可能为-1
    int h = options.outHeight;
    int w = options.outWidth;
    if (h > 0 && w > 0) {
        int beWidth = w / width;
        int beHeight = h / height;
        int be = 1;
        if (beWidth < beHeight) {
            be = beWidth;
        } else {
            be = beHeight;
        }
        if (be <= 0) {
            be = 1;
        }
        options.inSampleSize = be;
        // 重新读入图片，读取缩放后的bitmap，注意这次要把options.inJustDecodeBounds 设为 false
        bitmap = BitmapFactory.decodeFile(path, options);
        // 利用ThumbnailUtils来创建缩略图，这里要指定要缩放哪个Bitmap对象
        bitmap = ThumbnailUtils.extractThumbnail(bitmap, width, height,
                ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
    }

    return bitmap;
}

public static Bitmap getVideoFileThumbnail(File file, int width, int height) {
    // MINI_KIND: 512 x 384 ； MICRO_KIND: 96 x 96
    Bitmap thumb = null;
    if (width > 96 || height > 96) {
        // 大于96 x 96，则取MINI_KIND的缩略图并在此基础上再次抽取
        thumb = ThumbnailUtils.extractThumbnail(ThumbnailUtils
                .createVideoThumbnail(file.getAbsolutePath(),
                        Thumbnails.MINI_KIND), width, height,
                ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
    } else if (width == 96 && height == 96) {
        thumb = ThumbnailUtils.createVideoThumbnail(file.getAbsolutePath(),
                Thumbnails.MICRO_KIND);
    } else {
        // 小于96 x 96，则取MICRO_KIND的缩略图并在此基础上再次抽取
        thumb = ThumbnailUtils.extractThumbnail(ThumbnailUtils
                .createVideoThumbnail(file.getAbsolutePath(),
                        Thumbnails.MICRO_KIND), width, height,
                ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
    }

    return thumb;
}

/**
 * http://blog.csdn.net/toni001/article/details/6724785
 * 
 * @param file
 * @return
 */
public static Bitmap getMP3Thumbnail(File file) {
    int buffSize = 204800;//
    FileInputStream mp3ips = null;
    Bitmap bitmap = null;
    try {
        mp3ips = new FileInputStream(file);
        if (buffSize > mp3ips.available()) {
            buffSize = mp3ips.available();
        }
        byte[] buff = new byte[buffSize];
        mp3ips.read(buff, 0, buffSize);
        if (indexOf("ID3".getBytes(), buff, 1, 512) == -1) {
            // No ID3V2
            return null;
        }
        if (indexOf("APIC".getBytes(), buff, 1, 512) != -1) {
            int searLen = indexOf(new byte[] {
                    (byte) 0xFF, (byte) 0xFB
            },
                    buff);
            int imgStart = indexOf(new byte[] {
                    (byte) 0xFF, (byte) 0xD8
            },
                    buff);
            int imgEnd = lastIndexOf(
                    new byte[] {
                            (byte) 0xFF, (byte) 0xD9
                    }, buff, 1,
                    searLen) + 2;
            byte[] imgb = cutBytes(imgStart, imgEnd, buff);
            bitmap = BitmapFactory.decodeByteArray(imgb, 0, imgb.length);
        } else {
            // No APIC
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (mp3ips != null) {
            try {
                mp3ips.close();
            } catch (Exception e2) {
            }
        }
    }

    return bitmap;
}

/**
 * 正向索引
 */
public static int indexOf(byte[] tag, byte[] src) {
    return indexOf(tag, src, 1, src.length);
}

/**
 * 获取第index个的位置<br />
 * index从1开始
 */
private static int indexOf(byte[] tag, byte[] src, int index, int len) {
    if (len > src.length) {
        try {
            throw new Exception("大于总个数");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    int tagLen = tag.length;
    byte[] tmp = new byte[tagLen];
    for (int j = 0; j < len - tagLen + 1; j++) {
        for (int i = 0; i < tagLen; i++) {
            tmp[i] = src[j + i];
        }
        // 判断是否相等
        for (int i = 0; i < tagLen; i++) {
            if (tmp[i] != tag[i])
                break;
            if (i == tagLen - 1) {
                return j;
            }
        }

    }
    return -1;
}

/**
 * 倒序获取第index个的位置<br />
 * index从1开始
 */
private static int lastIndexOf(byte[] tag, byte[] src, int index, int len) {
    if (len > src.length) {
        try {
            throw new Exception("大于总个数");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    int size = 0;
    int tagLen = tag.length;
    byte[] tmp = new byte[tagLen];
    for (int j = len - tagLen; j >= 0; j--) {
        for (int i = 0; i < tagLen; i++) {
            tmp[i] = src[j + i];

        }
        for (int i = 0; i < tagLen; i++) {
            if (tmp[i] != tag[i])
                break;
            if (i == tagLen - 1) {
                size++;
                return j;
            }
        }

    }
    return -1;
}

/**
 * 截取byte[]
 */
private static byte[] cutBytes(int start, int end, byte[] src) {
    if (end <= start || start < 0 || end > src.length) {
        return null;
    }
    byte[] tmp = new byte[end - start];
    for (int i = 0; i < end - start; i++) {
        tmp[i] = src[start + i];
    }
    return tmp;
}

/**
 * 获取apk文件按指定尺寸缩放过的缩略图
 * 
 * @param context
 * @param apkPath
 * @return
 */
public static Bitmap getApkResizedIcon(Context context, String apkPath,
        int width, int height) {
    Bitmap thumb = getApkIcon(context, apkPath);
    if (thumb != null) {
        return ThumbnailUtils.extractThumbnail(thumb, width, height,
                ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
    }
    return thumb;
}

/**
 * 获取apk文件缩略图将不会改变icon大小
 * 
 * @param context
 * @param apkPath
 * @return
 */
public static Bitmap getApkIcon(Context context, String apkPath) {
    Bitmap thumb = null;
    PackageManager pm = context.getPackageManager();
    PackageInfo info = pm.getPackageArchiveInfo(apkPath,
            PackageManager.GET_ACTIVITIES);
    if (info != null) {
        ApplicationInfo appInfo = info.applicationInfo;
        appInfo.sourceDir = apkPath;
        appInfo.publicSourceDir = apkPath;
        try {
            thumb = ((BitmapDrawable) appInfo.loadIcon(pm)).getBitmap();
        } catch (OutOfMemoryError e) {

        }
    }
    return thumb;
}