java - Android:无法读取用户使用 URI 中的 getString() 和 getPath() 选择的 PDF 文件

Question

我正在使用 PdfBox-Android ( https://github.com/TomRoush/PdfBox-Android ) 库来读取 PDF 文件。当用户单击按钮(w/id file1)时，会弹出一个文件选择器，他或她可以在其中选择要读入的 pdf 文件。但是，当我从用户选择的 URI 中获取 URI 时，文件并使用 EITHER getString() 或 getPath() 获取文件名，我收到以下错误(使用 toString()):

Exception: java.io.FileNotFoundException: content:/com.android.providers.downloads.documents/document/7306: open failed: ENOENT (No such file or directory)

使用 getPath() 时出现以下错误:

Exception java.io.FileNotFoundException: /document/7097: open failed: ENOENT (No such file or directory)

下面是我的代码:

import com.tom_roush.pdfbox.pdmodel.PDDocument
import com.tom_roush.pdfbox.text.PDFTextStripper
import com.tom_roush.pdfbox.util.PDFBoxResourceLoader

// File picker implementation
private fun chooseFile(view:View) {
    println("chooseFile activated!");
    var selectFile = Intent(Intent.ACTION_GET_CONTENT)
    selectFile.type = "*/*"
    selectFile = Intent.createChooser(selectFile, "Choose a file")
    startActivityForResult(selectFile, READ_IN_FILE)
}


/* After startActivityForResult is executed, when the selectFile Intent is completed, onActivityResult is executed with
   the result code READ_IN_FILE.*/
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)

    if (requestCode == READ_IN_FILE) { // Step 1: When a result has been received, check if it is the result for READ_IN_FILE
        if (resultCode == Activity.RESULT_OK) { // Step 2: Check if the operation to retrieve thea ctivity's result is successful
            // Attempt to retrieve the file
            try {
                // Retrieve the true file path of the file
                var uri: Uri? = data?.getData();
                    // Initialize and load the PDF document reader for the file the user selected
                    var document = PDDocument.load(File(uri?.path));

                    // Read in the text of the PDF document
                    var documentText = PDFTextStripper().getText(document);

                    println("documentText = " + documentText);

                    document.close();
            } catch (e: Exception) { // If the app failed to attempt to retrieve the error file, throw an error alert
                println("EXCEPTION: " + e.toString());
            }
        }
    }
}

@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    // Initialize the PDFBox library's resource loader
    PDFBoxResourceLoader.init(applicationContext);

    setContentView(R.layout.activity_main)

    var file1:Button = findViewById(R.id.file1);
    file1.setOnClickListener(::chooseFile)
}

Answer 1

在调用 PDFBox 之前，强烈建议初始化库的资源加载器。在调用 PDFBox 方法之前添加以下行:

PDFBoxResourceLoader.init(getApplicationContext());

所以编辑你的代码

.....
@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
   setContentView(R.layout.activity_main)

   PDFBoxResourceLoader.init(getApplicationContext());//call this
   var file1:Button = findViewById(R.id.file1);
   file1.setOnClickListener(::chooseFile)
}