Android开启失败：EACCES（Permission denied）在执行PDF阅读程序库

Question

我正在为PDF阅读程序执行this库。我已经按照链接中的说明实施了代码。但是当我运行时，我得到了异常。这里的logcat的：

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 

也是我在我的AndroidManifest.xml中添加以下行：

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 

，但仍然得到了同样的异常

Answer 1

简单的解决方案：设置你的目标SDK回到22

清洁解决方案：请求运行时间P ermissions

检查this了解更多信息。