Android的MediaPlayer的到文件的完整路径路径、完整、文件、Android
我需要的完整路径的文件在手机上（任何地点），所以用的MediaPlayer播放。
I need to get the full path to a file somewhere on the phone (any location) and play it with MediaPlayer.
香港专业教育学院听说过使用文件选择为Android（通过启动意图）的。
ive heard of using a file chooser for Android (by launching an intent).
在试code，我刚才复制的资源到另一个文件，得到了路径，并通过它来AudioVideoEntry（正如我在后，围绕MediaPlayer的一个非常简单的瘦包装）
In the test code, I just copied a resource to a another file, got the path and passed it to AudioVideoEntry (as i show later, a very simple and thin wrapper around MediaPlayer)
下面是测试code我已经写了：
Here's the test code I've written:
private String ave_path;
private String ave_file_name = "my_media_content";
private InputStream ave_fis;
private OutputStream ave_fos;
public void testAudioVideoEntry()
{
//get the Activity
Module_JournalEntry journalentryactivity = getActivity();
//open an InputStream to a resource file (in this case strokes.mp3)
ave_fis = journalentryactivity.getResources().openRawResource(module.jakway.JournalEntry.R.raw.strokes);
//open an OutputStream to a new file
try {
ave_fos = journalentryactivity.openFileOutput(ave_file_name,
Context.MODE_PRIVATE);
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
assertTrue(false);
}
catch(Exception e)
{
assertTrue(false);
}
//copy the data from the resource into
//the OutputStream
int data;
try {
while((data = ave_fis.read()) != -1)
{
ave_fos.write(data);
}
assertTrue(true);
}
catch(Exception e)
{
assertTrue(false);
}
//get the full path of the file we wrote to
ave_path = journalentryactivity.getFileStreamPath(ave_file_name).toString();
//and construct a new object of AudioVideoEntry with that path
AudioVideoEntry ave = new AudioVideoEntry(ave_path);
//register an error listener via MediaPlayer's setOnErrorListener
ave.setOnErrorListener(new OnErrorListener()
{
@Override
public boolean onError(MediaPlayer mp,
int what, int extra) {
Log.e("MEDIAPLAYER ERRORS",
"what: " + what + " extra: " + extra);
assertTrue(false);
// TODO Auto-generated method stub
return false;
}
});
ave.prepareMedia();
ave.playMedia();
try {
ave_fis.close();
ave_fos.close();
}
catch(Exception e)
{
assertTrue(false);
e.printStackTrace();
}
AudioVideoEntry基本上是一个简单包装的MediaPlayer，可以容纳自己的道路：
AudioVideoEntry is basically a thin wrapper around MediaPlayer that can hold its own path:
public class AudioVideoEntry
{
private String path_to_audio_file;
private MediaPlayer mediaplayer;
/**
* Initialize the internal MediaPlayer
* from the String parameter
* @param set_path_to_audio_file
*/
public AudioVideoEntry(String set_path_to_audio_file)
{
path_to_audio_file = set_path_to_audio_file;
mediaplayer = new MediaPlayer();
try {
mediaplayer.setDataSource(path_to_audio_file);
mediaplayer.prepare();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public AudioVideoEntry(FileDescriptor fd)
{
mediaplayer = new MediaPlayer();
try {
mediaplayer.setDataSource(fd);
mediaplayer.prepare();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* Begin playing media
*/
public void prepareMedia()
{
try {
mediaplayer.prepare();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* play media
* don't forget to prepare() if necessary
*/
public void playMedia()
{
mediaplayer.start();
}
/**
* pause the media
* can be played later
*/
public void pauseMedia()
{
mediaplayer.pause();
}
/**
* stop media
*/
public void stopMedia()
{
mediaplayer.stop();
}
public void setOnErrorListener(OnErrorListener listener)
{
mediaplayer.setOnErrorListener(listener);
}
}
下面是从JUnit测试输出的logcat（试验是成功的，实际的结果 - 作为logat显示 - 没有）
here's the logcat output from the JUnit test (the tests were successful, the actual results - as the logat shows - were not)
02-07 09:40:23.129: ERROR/MediaPlayer(1209): error (1, -2147483648)
02-07 09:40:23.139: WARN/System.err(1209): java.io.IOException: Prepare failed.: status=0x1
02-07 09:40:23.149: WARN/System.err(1209): at android.media.MediaPlayer.prepare(Native Method)
02-07 09:40:23.149: WARN/System.err(1209): at module.jakway.JournalEntry.AudioVideoEntry.<init>(AudioVideoEntry.java:39)
02-07 09:40:23.149: WARN/System.err(1209): at module.jakway.JournalEntry.test.Module_JournalEntryTest.testAudioVideoEntry(Module_JournalEntryTest.java:182)
02-07 09:40:23.149: WARN/System.err(1209): at java.lang.reflect.Method.invokeNative(Native Method)
02-07 09:40:23.149: WARN/System.err(1209): at java.lang.reflect.Method.invoke(Method.java:507)
02-07 09:40:23.159: WARN/System.err(1209): at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:204)
02-07 09:40:23.159: WARN/System.err(1209): at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:194)
02-07 09:40:23.159: WARN/System.err(1209): at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:186)
02-07 09:40:23.159: WARN/System.err(1209): at junit.framework.TestCase.runBare(TestCase.java:127)
02-07 09:40:23.169: WARN/System.err(1209): at junit.framework.TestResult$1.protect(TestResult.java:106)
02-07 09:40:23.169: WARN/System.err(1209): at junit.framework.TestResult.runProtected(TestResult.java:124)
02-07 09:40:23.169: WARN/System.err(1209): at junit.framework.TestResult.run(TestResult.java:109)
02-07 09:40:23.179: WARN/System.err(1209): at junit.framework.TestCase.run(TestCase.java:118)
02-07 09:40:23.179: WARN/System.err(1209): at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:169)
02-07 09:40:23.179: WARN/System.err(1209): at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:154)
02-07 09:40:23.179: WARN/System.err(1209): at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:529)
02-07 09:40:23.189: WARN/System.err(1209): at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1447)
02-07 09:40:23.189: ERROR/MediaPlayer(1209): prepareAsync called in state 0
02-07 09:40:23.189: WARN/System.err(1209): java.lang.IllegalStateException
02-07 09:40:23.189: WARN/System.err(1209): at android.media.MediaPlayer.prepare(Native Method)
02-07 09:40:23.189: WARN/System.err(1209): at module.jakway.JournalEntry.AudioVideoEntry.prepareMedia(AudioVideoEntry.java:79)
02-07 09:40:23.199: WARN/System.err(1209): at module.jakway.JournalEntry.test.Module_JournalEntryTest.testAudioVideoEntry(Module_JournalEntryTest.java:197)
02-07 09:40:23.199: WARN/System.err(1209): at java.lang.reflect.Method.invokeNative(Native Method)
02-07 09:40:23.199: WARN/System.err(1209): at java.lang.reflect.Method.invoke(Method.java:507)
02-07 09:40:23.199: WARN/System.err(1209): at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:204)
02-07 09:40:23.199: WARN/System.err(1209): at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:194)
02-07 09:40:23.199: WARN/System.err(1209): at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:186)
02-07 09:40:23.199: WARN/System.err(1209): at junit.framework.TestCase.runBare(TestCase.java:127)
02-07 09:40:23.199: WARN/System.err(1209): at junit.framework.TestResult$1.protect(TestResult.java:106)
02-07 09:40:23.199: WARN/System.err(1209): at junit.framework.TestResult.runProtected(TestResult.java:124)
02-07 09:40:23.199: WARN/System.err(1209): at junit.framework.TestResult.run(TestResult.java:109)
02-07 09:40:23.199: WARN/System.err(1209): at junit.framework.TestCase.run(TestCase.java:118)
02-07 09:40:23.199: WARN/System.err(1209): at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:169)
02-07 09:40:23.199: WARN/System.err(1209): at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:154)
02-07 09:40:23.199: WARN/System.err(1209): at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:529)
02-07 09:40:23.199: WARN/System.err(1209): at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1447)
02-07 09:40:23.199: ERROR/MediaPlayer(1209): start called in state 0
02-07 09:40:23.199: ERROR/MediaPlayer(1209): error (-38, 0)
编辑：为什么失败的MediaPlayer
why is MediaPlayer failing?
感谢！ dragonwrenn
thanks! dragonwrenn
推荐答案
要的MediaPlayer。prepare第二次调用（）（已调用一次在AudioVideoEntry构造函数）在AudioVideoEntry。prepareMedia（）方法很容易发现其他人都注意到了。
The second call to MediaPlayer.prepare() (already called once in the AudioVideoEntry ctor) in the AudioVideoEntry.prepareMedia() method was easy to spot as other people have noticed.
更困难的错误找到了第一个错误。
The harder error to find was the first error.
我使用的奥格文件进行测试。
I used an Ogg file for testing.
第一条线索是从davidsparks回复的android-platform - 奥格在G1
First clue was from davidsparks reply (last one) in android-platform - Ogg on G1
只要文件具有.OGG扩展，他们应该与玩 内置的音乐播放器。我们依靠的文件扩展名，因为有 没有集中的文件识别为媒体扫描仪。
As long as the files have a .ogg extension, they should play with the built-in music player. We rely on the file extensions because there is no centralized file recognizer for the media scanner.
第二条线索是从[android-developers]回复：关于MediaPlayer的文件权限
Second clue was from [android-developers] Re: File permission about MediaPlayer
由于Android的安全模型，MediaPlayer的没有根 访问权限。它可以访问的SD卡，但它不能访问私人 应用程序目录。
Due to the Android security model, MediaPlayer does not have root access rights. It can access the sdcard, but it can't access private app directories.
您的应用程序可以明确授予的MediaPlayer临时访问安全 通过打开该文件并传递文件描述符文件 MediaPlayer的使用的setDataSource（FD FileDescriptor的）方法。
Your app can explicitly grant MediaPlayer temporary access to secure files by opening the file and passing the file descriptor to MediaPlayer using the setDataSource(FileDescriptor fd) method.
如果你看一下输出流的绝对路径，你看到它在 /数据/数据应用程序的包名的目录下的目录。
If you look at the absolute path of the output stream, you see it's in the /data/data directory under the app's package name's directory.
对不起时间戳 - 我的工作向后获得的数据显示一个OS2.1update1（API7）模拟器
Excuse the timestamps - I worked backwards to get data to show on a OS2.1update1 (API7) emulator.
您code有：
String ave_file_name = "my_media_content";
ave_fos = activity.openFileOutput(ave_file_name, Context.MODE_PRIVATE);
DDMS显示：
DDMS showed:
02-10 05:10:28.253: WARN/MediaPlayer(1992): info/warning (1, 26)
02-10 05:10:28.253: ERROR/PlayerDriver(31): Command PLAYER_SET_DATA_SOURCE completed with an error or info PVMFErrNotSupported
02-10 05:10:28.253: ERROR/MediaPlayer(1992): error (1, -4)
02-10 05:10:28.274: WARN/PlayerDriver(31): PVMFInfoErrorHandlingComplete
如果我们改变 JUST 的文件MODE_WORLD_READABLE：
If we change JUST the file to MODE_WORLD_READABLE:
String ave_file_name = "my_media_content";
ave_fos = activity.openFileOutput(ave_file_name, Context.MODE_WORLD_READABLE);
DDMS没有呈现改善迹象：
DDMS shows no improvement:
02-10 05:08:28.543: WARN/MediaPlayer(1900): info/warning (1, 26)
02-10 05:08:28.553: ERROR/PlayerDriver(31): Command PLAYER_SET_DATA_SOURCE completed with an error or info PVMFErrNotSupported
02-10 05:08:28.553: ERROR/MediaPlayer(1900): error (1, -4)
02-10 05:08:28.563: WARN/PlayerDriver(31): PVMFInfoErrorHandlingComplete
如果我们改变 JUST 文件扩展名 OGG ：
If we change JUST the file extension to ogg:
String ave_file_name = "my_media_content.ogg";
ave_fos = activity.openFileOutput(ave_file_name, Context.MODE_PRIVATE);
我们得到DDMS输出的变化：
We get a change in DDMS output:
02-10 04:59:30.153: ERROR/MediaPlayerService(31): error: -2
02-10 04:59:30.163: ERROR/MediaPlayer(1603): Unable to to create media player
但是，当我们的将二者结合起来
String ave_file_name = "my_media_content.ogg";
ave_fos = activity.openFileOutput(ave_file_name, Context.MODE_WORLD_READABLE);
DDMS显示没有错误。
DDMS shows no errors.
