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javaandroidandroid-studiojava-native-interfaceandroidpdfviewer

Android: Trying to compile native code, getting UnsatisfiedLinkError: No implementation found

I am trying to fork AndroidPdfViewer to replace its underlying library from PdfiumAndroid to android-pdfium.

My problem is, when I load AndroidPdfViewer and PdfiumAndroid in Android Studio, I can't get the project to work, even before changing anything.

The problem is PdfiumAndroid has JNI code that define many previously declared functions, but the linker can't link the definitions in C++ to the declarations in Java. The error message has two errors:

E/barteksc.sample: No implementation found for long com.shockwave.pdfium.PdfiumCore.nativeOpenDocument(int, java.lang.String) (tried Java_com_shockwave_pdfium_PdfiumCore_nativeOpenDocument and Java_com_shockwave_pdfium_PdfiumCore_nativeOpenDocument__ILjava_lang_String_2)
E/PDFView: load pdf error
    java.lang.UnsatisfiedLinkError: No implementation found for long com.shockwave.pdfium.PdfiumCore.nativeOpenDocument(int, java.lang.String) (tried Java_com_shockwave_pdfium_PdfiumCore_nativeOpenDocument and Java_com_shockwave_pdfium_PdfiumCore_nativeOpenDocument__ILjava_lang_String_2)
        at com.shockwave.pdfium.PdfiumCore.nativeOpenDocument(Native Method)
        at com.shockwave.pdfium.PdfiumCore.newDocument(PdfiumCore.java:135)

Here is the gradle file. It looks like there is something missing, although these are the original files before any modifications.

I tried to add this to proguard-rules.pro

-keep class com.shockwave.** { *; }

it removed the first error, but the second is still there.

Solution

  • Solved it.

    If anyone is having the same issue, I did the following to solve it:

    • Installed android-ndk tools
    • Edited Application.mk file to remove mips and mips64 since they are not supported anymore, and updated android version to 19 since it's the minimum right now.
    • run ndk-build in the jni folder / directory.

    That created what I was said about in my question

    It looks like there is something missing

    That created a libs folder that has the necessary definitions for the linker.