我正在为PDF阅读器实施this库。我已经按照链接中的说明实现了代码。但是当我跑步时，我得到了以下异常。这里是logcat：
10:43:56.429 32577-32577/com.example.fahad.testpdfreaderlibrary I/PDFVIEWER: Intent { cmp=com.example.fahad.testpdfreaderlibrary/.TestPDFActivity (has extras) }
11-05 10:43:56.431 32577-32577/com.example.fahad.testpdfreaderlibrary I/PDFVIEWER: ST='file '/storage/emulated/0/pdf.pdf' has 433994 bytes'
11-05 10:43:56.432 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: java.io.FileNotFoundException: /storage/emulated/0/pdf.pdf: open failed: EACCES (Permission denied)
11-05 10:43:56.432 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at libcore.io.IoBridge.open(IoBridge.java:452)
11-05 10:43:56.432 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at java.io.RandomAccessFile.<init>(RandomAccessFile.java:117)
11-05 10:43:56.432 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at net.sf.andpdf.pdfviewer.PdfViewerActivity.openFile(PdfViewerActivity.java:841)
11-05 10:43:56.432 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at net.sf.andpdf.pdfviewer.PdfViewerActivity.parsePDF(PdfViewerActivity.java:815)
11-05 10:43:56.432 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at net.sf.andpdf.pdfviewer.PdfViewerActivity.setContent(PdfViewerActivity.java:221)
11-05 10:43:56.432 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at net.sf.andpdf.pdfviewer.PdfViewerActivity.onCreate(PdfViewerActivity.java:212)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.app.Activity.performCreate(Activity.java:6237)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.app.ActivityThread.-wrap11(ActivityThread.java)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.os.Handler.dispatchMessage(Handler.java:102)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.os.Looper.loop(Looper.java:148)
11-05 10:43:56.433 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5417)
11-05 10:43:56.434 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at java.lang.reflect.Method.invoke(Native Method)
11-05 10:43:56.434 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
11-05 10:43:56.434 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
11-05 10:43:56.434 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)
11-05 10:43:56.434 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at libcore.io.Posix.open(Native Method)
11-05 10:43:56.434 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
11-05 10:43:56.434 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: at libcore.io.IoBridge.open(IoBridge.java:438)
11-05 10:43:56.434 32577-32577/com.example.fahad.testpdfreaderlibrary W/System.err: ... 17 more
我还在AndroidManifest.xml中添加了以下几行：
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
但仍然得到相同的异常