How to resolve the Java Exception In Initialize error?-CodePudding

I am creating an app where I can extract the text from the pdf. For this I am using PdfBox library. But when I import pdf from the file manager, app stops and it gives exception in Initialize error at line where PDFTextStripper is initialized. How can I solve this problem?

Below is the function for extracting the text from pdf.

private fun extractTextPdfFile() {
   var document: PDDocument? = null
    var parsedText: String? = null
    try {
        val inputStream: InputStream? = this.contentResolver.openInputStream(fileUri!!)
        document = PDDocument.load(inputStream)
    } catch (e: IOException) {
        e.printStackTrace()
    }

    try {
        val pdfStripper = PDFTextStripper()
        pdfStripper.startPage = 0
        if (document != null) {
            pdfStripper.endPage = 1
        }
        parsedText="Parsed text: "   pdfStripper.getText(document)
    } catch (e: IOException) {
        e.printStackTrace()
    } finally {
        try {
            document?.close()
        } catch (e: IOException) {
            e.printStackTrace()
        }
    }
    findViewById<TextView>(R.id.file_path).text=parsedText

 }
}

I have used registerForActivityResult for getting the pdf document Uri.

private var fileUri: Uri? = null
private val getContent =
    registerForActivityResult(ActivityResultContracts.GetContent()) { uri: Uri? ->
        // Handle the returned Uri
        if (uri != null) {
            fileUri = uri
        } else {
            Toast.makeText(
                this,
                "Cannot fetch document from the file manager",
                Toast.LENGTH_SHORT
            ).show()
        }
    }
  
 override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    findViewById<Button>(R.id.Import).setOnClickListener {
        getContent.launch("application/pdf")
        if (fileUri != null)
            extractTextPdfFile()
    }
}

This is the exception which I am getting. I don't know how it is now giving null pointer exception, earlier it was giving the exception which I had mentioned.

 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void java.io.InputStream.close()' on a null object reference
    at com.tom_roush.pdfbox.text.PDFTextStripper.<clinit>(PDFTextStripper.java:1874)
    at com.example.doctranslator.MainActivity.extractTextPdfFile(MainActivity.kt:82) 
    at com.example.doctranslator.MainActivity.onCreate$lambda-1(MainActivity.kt:44) 
    at com.example.doctranslator.MainActivity.$r8$lambda$8z4EEPr6Q6JatIakz-DO65v-zdE(Unknown Source:0) 
    at com.example.doctranslator.MainActivity$$ExternalSyntheticLambda0.onClick(Unknown Source:2) 
    at android.view.View.performClick(View.java:8160) 
    at android.widget.TextView.performClick(TextView.java:16222) 
    at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119) 
    at android.view.View.performClickInternal(View.java:8137) 
    at android.view.View.access$3700(View.java:888) 
    at android.view.View$PerformClick.run(View.java:30236) 
    at android.os.Handler.handleCallback(Handler.java:938) 
    at android.os.Handler.dispatchMessage(Handler.java:99) 
    at android.os.Looper.loop(Looper.java:246) 
    at android.app.ActivityThread.main(ActivityThread.java:8595) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)

CodePudding user response：

Are you sure the PdfBox library is getting compiled into your code? Because if its an error which happens on initialization it seems to be a compilation error since it cannot refer to the library.

You should get some kotlin code to compile your dependencies into your built app.

CodePudding user response：

It sounds like you haven't called PDFBoxResourceLoader.init(Context) before using PDFTextStripper. This is required to load certain files used by PdfBox-Android like BidiMirroring.txt.

I added PDFBoxResourceLoader.init(applicationContext) to your onCreate function and was able to extract text successfully using your code.