从外部存储读取视频文件时出现 IllegalArgumentException

Question

我有一个问题，从 SD 卡读取视频文件时遇到 IllegalArgumentException。我不知道为什么？请向我建议正确的解决方案。

错误堆栈：

11-03 18:56:18.733: ERROR/AndroidRuntime(24192): FATAL EXCEPTION: main
11-03 18:56:18.733: ERROR/AndroidRuntime(24192): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example/com.example.TestCryptoActivity}: java.lang.IllegalArgumentException: File /mnt/sdcard/E0022505.mp4 contains a path separator
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.os.Looper.loop(Looper.java:123)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.ActivityThread.main(ActivityThread.java:4627)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at java.lang.reflect.Method.invokeNative(Native Method)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at java.lang.reflect.Method.invoke(Method.java:521)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at dalvik.system.NativeStart.main(Native Method)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192): Caused by: java.lang.IllegalArgumentException: File /mnt/sdcard/E0022505.mp4 contains a path separator
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.ContextImpl.makeFilename(ContextImpl.java:1602)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.ContextImpl.openFileInput(ContextImpl.java:399)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.content.ContextWrapper.openFileInput(ContextWrapper.java:152)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at com.example.TestCryptoActivity.onCreate(TestCryptoActivity.java:29)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
11-03 18:56:18.733: ERROR/AndroidRuntime(24192):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)

代码：

    try {
        is = this.openFileInput(Environment.getExternalStorageDirectory()+"/E0022505.mp4");
    } catch (FileNotFoundException e2) {
        // TODO Auto-generated catch block
        e2.printStackTrace();
    }
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] b = new byte[2097152];
try {
        while ((bytesRead  = is.read(b)) != -1) {
           bos.write(b, 0, bytesRead);
        }
    } catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
byte[] bytes = bos.toByteArray();
try {
        String byteString = new String(bytes,"UTF-8");
        System.out.println("the bytes array of video:"+byteString);
    } catch (UnsupportedEncodingException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

Answer 1

Context.openFileInput 不允许使用路径分隔符，因为它仅用于应用程序上下文中的私有文件。

http://developer.android.com/reference /android/content/Context.html#openFileInput(java.lang.String)

打开与此 Context 的应用程序包关联的私有文件进行读取。

您可以通过其他方式打开该文件（File 、FileInputStream 等），因为它位于sdcard，但您不能使用 openFileInput 来实现此目的。

Answer 2

我认为，此方法在应用程序的私有数据区域中打开一个文件。您无法打开该区域的子目录中的任何文件。因此，请使用 FileInputStream 等。

希望有帮助。