系统媒体库不了解的线看这儿:
Android media媒体库分析之:MediaProvider http://www.linuxidc.com/Linux/2015-03/114755.htm
Android media媒体库分析之:调用系统媒体库完成指定媒体文件扫描 http://www.linuxidc.com/Linux/2015-03/114756.htm
先看一下要实现的效果:
![Android media媒体库分析之:分类别统计媒体文件大小_第1张图片](http1://img.it610.com/image/product/45a8e7bcb3aa471582b6dde79da15c10.jpg)
上图是系统设置中分类别对文件所占空间的统计,项目中要统计媒体文件所占空间,于是研究了一下系统的做法,收获如下:
1、从源码packages/app/下找到settings工程,找到存储功能的实现,相关类有:
com.android.settings.deviceinfo.StorageMeasurement
com.android.settings.deviceinfo.StorageVolumePreferenceCategory
其他相关源码:
com.android.defcontainer.DefaultContainerService
StorageMeasurement类中启动服务,绑定服务,通知界面更新;
StorageVolumePreferenceCategory显示界面
StorageMeasurement中建立了与DefaultContainerService服务的通信,指定要扫描的目录:
/** Media types to measure on external storage. */
private static final Set
Environment.DIRECTORY_DCIM, Environment.DIRECTORY_MOVIES,
Environment.DIRECTORY_PICTURES, Environment.DIRECTORY_MUSIC,
Environment.DIRECTORY_ALARMS, Environment.DIRECTORY_NOTIFICATIONS,
Environment.DIRECTORY_RINGTONES, Environment.DIRECTORY_PODCASTS,
Environment.DIRECTORY_DOWNLOADS, Environment.DIRECTORY_ANDROID);
上面这个set就是定义了我们系统里面常用的目录:
public static String DIRECTORY_DOWNLOADS = "Download";
public static String DIRECTORY_DCIM = "DCIM";
public static String DIRECTORY_MUSIC = "Music";
public static String DIRECTORY_PICTURES = "Pictures";
public static String DIRECTORY_MOVIES = "Movies";
...
获取每个目录的大小:
for (String type : sMeasureMediaTypes) {
final File path = currentEnv.getExternalStoragePublicDirectory(type);
final long size = getDirectorySize(imcs, path);
details.mediaSize.put(type, size);
}
其中getDirectorySize方法通过IMediaContainerService调用了DefaultContainerService服务中的方法,在DefaultContainerService中获取到所有信息之后回调IMediaContainerService,再更新界面;
也就是说:系统只统计了上述几个目录的大小(sMeasureMediaTypes中定义的),如果你的歌曲是拷贝到其他目录,那系统存储里面是不会统计使用量。看来Android也不是很智能嘛!!!难度是考虑效率???
2、如何获取某个目录的大小?
先看一下系统是怎么做的:
下面方法是在DefaultContainerService中定义的,获取某一目录大小,获取某一文件大小;
@Override
public long calculateDirectorySize(String path) throws RemoteException {
Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
final File directory = new File(path);
if (directory.exists() && directory.isDirectory()) {
return MeasurementUtils.measureDirectory(path);
} else {
return 0L;
}
}
@Override
public long[] getFileSystemStats(String path) {
Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
try {
final StructStatFs stat = Libcore.os.statfs(path);
final long totalSize = stat.f_blocks * stat.f_bsize;
final long availSize = stat.f_bavail * stat.f_bsize;
return new long[] { totalSize, availSize };
} catch (ErrnoException e) {
throw new IllegalStateException(e);
}
}
但是
MeasurementUtils.measureDirectory(path)和Libcore.os.statfs(path)
两个方法我们都调不到,怎么办?
我们把MeasurementUtils类从源码中拷贝出来到我们的功能,但注意要保留包路径,否则可以编译通过,但无法运行,因为他里面用到了一个本地方法,需要加载一个so文件。如下:
这样就可以解决第一个问题了;
再来看第二方法,其实这个方法我们用不到,我们已经通过第一个方法获取到指定文件夹的大小了,那关于某一个文件的大小我们之间通过file可以拿到。
第二个方法有一个封装类:starfs,可以获取rom、sdcard的总大小和可用空间,如下:
/**
* The size, in bytes, of a block on the file system. This corresponds to
* the Unix {@code statfs.f_bsize} field.
*/
public int getBlockSize() {
return (int) mStat.f_bsize;
}
/**
* The total number of blocks on the file system. This corresponds to the
* Unix {@code statfs.f_blocks} field.
*/
public int getBlockCount() {
return (int) mStat.f_blocks;
}
这个可以直接在我们获取总体容量时使用。
上面把系统是怎么做的大概搞清楚,下面我们来实现我们的需求:
一、思路:
1、Android media媒体库分析之:调用系统媒体库完成指定媒体文件扫描 http://www.linuxidc.com/Linux/2015-03/114756.htm
这篇文章可以知道,媒体文件(音频、视频、图片)系统完成扫描之后就存入了数据库,那我们可以查询数据库,得到所有媒体文件,把这些文件的大小相加。
2、由于sdcard可以会unmount,所以在相加时要根据路径判断此文件是否存在;
3、下面时我实现的工具类,希望对你有用:
package com.linuxidc.jerome;
import java.io.File;
import java.util.ArrayList;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.os.StatFs;
import android.provider.MediaStore;
public class MemoryUtil {
Context mContext;
public MemoryUtil(Context context) {
mContext = context;
}
/**
* 获得SD卡总大小
*
* @return
*/
public long getSDTotalSize() {
File path = Environment.getExternalStorageDirectory();
StatFs stat = new StatFs(path.getPath());
long blockSize = stat.getBlockSize();
long totalBlocks = stat.getBlockCount();
return blockSize * totalBlocks;
}
/**
* 获得sd卡剩余容量,即可用大小
*
* @return
*/
public long getSDAvailableSize() {
File path = Environment.getExternalStorageDirectory();
StatFs stat = new StatFs(path.getPath());
long blockSize = stat.getBlockSize();
long availableBlocks = stat.getAvailableBlocks();
return blockSize * availableBlocks;
}
/**
* 获得机身内存总大小
*
* @return
*/
public long getRomTotalSize() {
File path = Environment.getDataDirectory();
StatFs stat = new StatFs(path.getPath());
long blockSize = stat.getBlockSize();
long totalBlocks = stat.getBlockCount();
return blockSize * totalBlocks;
}
/**
* 获得机身可用内存
*
* @return
*/
public long getRomAvailableSize() {
File path = Environment.getDataDirectory();
StatFs stat = new StatFs(path.getPath());
long blockSize = stat.getBlockSize();
long availableBlocks = stat.getAvailableBlocks();
return blockSize * availableBlocks;
}
/**
* 外部存储中所有音频文件所占内存
*
* @return
*/
public long getAudioTotalSize() {
ArrayList
long size = 0L;
for (MemoryInfo cInfo : resultList) {
File file = new File(cInfo.getFilePath());
if(null!=file &&file.exists()){
size += cInfo.getFileSize();
}
}
return size;
}
/**
* 外部存储中除音频、视频、图片之前其他文件所占内存
*
* @return
*/
public long getOtherTotalSize() {
long size = getSDTotalSize() - getSDAvailableSize()
- getPictureTotalSize() - getVideoTotalSize()
- getAudioTotalSize();
if (size < 0L) {
size = 0L;
}
return size;
}
/**
* 外部存储中所有图片文件所占内存
*
* @return
*/
public long getPictureTotalSize() {
ArrayList
long size = 0L;
for (MemoryInfo cInfo : resultList) {
File file = new File(cInfo.getFilePath());
if(null!=file &&file.exists()){
size += cInfo.getFileSize();
}
}
return size;
}
/**
* 外部存储中所有视频文件所占内存
*
* @return
*/
public long getVideoTotalSize() {
ArrayList
long size = 0L;
for (MemoryInfo cInfo : resultList) {
File file = new File(cInfo.getFilePath());
if(null!=file &&file.exists()){
size += cInfo.getFileSize();
}
}
return size;
}
public ArrayList
//我们只需要两个字段:大小、文件路径
Cursor cursor = mContext.getContentResolver().query(
uri,new String[] { MediaStore.Audio.Media.SIZE,
MediaStore.Audio.Media.DATA }, null, null, null);
ArrayList
try{
if (cursor.moveToFirst()) {
do {
MemoryInfo mInfo = new MemoryInfo();
mInfo.setFileSize(cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.SIZE)));
mInfo.setFilePath(cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA)));
}while(cursor.moveToNext());
}
}finally{
if(cursor != null){
cursor.close();
}
}
return musicList;
}
class MemoryInfo {
private long fileSize = 0L;
private String filePath = "";
public long getFileSize() {
return fileSize;
}
public void setFileSize(long fileSize) {
this.fileSize = fileSize;
}
public String getFilePath() {
return filePath;
}
public void setFilePath(String filePath) {
this.filePath = filePath;
}
}
}