java.lang.UnsatisfiedLinkError slice-sqlite-jdbc-3.8.7

[thijssmudde]

Hi, im using the writer inside an Android App to create a new .mbtiles file in an AsyncTask class.

Here is my java code:

private class FetchData extends AsyncTask<String, Void, String> {
  private Exception exception;

  @Override
  protected String doInBackground(String... routeSelected) {
    MBTilesWriter w = null;
    String filePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/MyRoutes/" + routeSelected;
    try {
      outputFile = new File(filePath);
      w = new MBTilesWriter(outputFile);
      new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/MyRoutes").mkdirs();
    } catch (MBTilesWriteException e) {
      this.exception = e;
      System.out.println("exception: " + e);
      return "";
    }

    //Irrelevant code removed here...

    return filePath;
  }
}

It cannot instantiate a new MBTilesWriter

Full error report on windows 10 x64 bit.
http://pastebin.com/raw/fhSH8qJr

build.gradle looks as follows

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    //compile 'org.imintel:mbtiles4j:1.0.5'
    compile 'org.xerial:sqlite-jdbc:3.8.7'
    compile 'commons-io:commons-io:2.5'

mbtiles4j is actually included inside my project: see screensot. There were other problems with including it through build.gradle, so I managed to workaround it like this. The mbtilesreader works fine!

[ghost]

Hi there

I believe your issue may be with your IntelliJ setup or something specific to Android's JVM. UnsatisifiedLinkErrors are typically due to some library attempting to load a native C library and failing to find/load said C library.

See if this related error helps you: http://stackoverflow.com/questions/35792459/java-lang-unsatisfiedlinkerror-com-android-tools-fd-runtime-incrementalclassloa

[thijssmudde]

@ccook thanks. I've disabled instant run in Android studio, now the error is:

couldn't find "libsqlitejdbc.so"

So like you said, a library could not be found. Do you have any resources on how to use sqllite properly in android studio?

[ghost]

No problem.

According to this stackoverflow (http://stackoverflow.com/questions/27067400/using-libraries-in-android-project), you'll require the sqlite libraries specifically compiled for android. This makes some sense since the jdbc driver I'm using in this project is probably expecting x86_64 sqlite. Android c libraries are compiled using ARM architecture.

I fear that the JDBC driver in this project is hard-coded to use the x86_64 version. You may have to fork the project to allow the JDBC Driver to use SQLDroid. You'd have to modify SQLHelper (https://github.com/imintel/mbtiles4j/blob/master/src/main/java/org/imintel/mbtiles4j/SQLHelper.java).

When creating the library, I had the opposite problem (every java implementation was just a reader made specifically for android), so I never envisioned the project being used in android projects.

[thijssmudde]

Awesome, I think I can work from here. If you'd like you can post your answer on this stackoverflow:
http://stackoverflow.com/questions/41509607/mbtileswriter-java-lang-unsatisfiedlinkerror-slice-sqlite-jdbc-3-8-7 and I'll accept it!

Thanks so much.

[thijssmudde]

hi @ccook, the android implementation is here: https://github.com/fullhdpixel/mbtiles4j

If you'd like to help me make this available through build.gradle, that would be awesome. I haven't done that before

[carlos-mg89]

@fullhdpixel did you finally made the library compatible with Gradle? I was so excited to see that you had done all this work of porting the MBTiles4J library to be Android compatible, but would like to use it as a Gradle dependency.