/android-spatialite

Spatialite database JNI wrapper for Android

Primary LanguageC

Release

android-spatialite

WHAT IS THIS?

  • The Spatialite database ported for Android
  • 100% offline, portable and self-contained as SQLite.

WHEN DO I NEED IT?

  • When you need deployment, collecting, processing and fast querying of small to huge amounts of geometry data (points, polylines, polygons, multipolygons, etc.) on Android devices.
  • When you want to be 100% independent from any server/cloud backend.

GETTING STARTED

If you know basic SQLite, there's almost nothing to learn. The API is 99% the same as the Android SQLite API (as of API level 15). The main difference is the packaging. Use org.spatialite.database.XYZ instead of android.database.sqlite.XYZ and org.spatialite.XYZ instead of android.database.XYZ. Same applies to the other classes - all platform SQLiteXYZ classes have their Spatialite versions.

Gradle

  1. Have this in your project's build.gradle:
allprojects {
  repositories {
    ...
    maven { url "https://jitpack.io" }
  }
}
  1. Add the following to your module's build.gradle:
compile 'com.github.sevar83:android-spatialite:2.0.0'

BUILD

v2.0.0 build with android-ndk-r14b

问题1

"A problem occurred starting process 'command 'ndk-build'"

ndk-build 未加入到系统变量

编译通过后如何使用

https://stackoverflow.com/questions/24357687/how-to-include-so-library-in-android-studio

http://www.javashuo.com/article/p-nexacefk-oc.html (makeJar)

EXAMPLE CODE

There is a very simple and useless example in the app module. Another example is the SpatiAtlas experiment.

HOW IT WORKS?

Works the same way as the platform SQLite. It's accessible through Java/JNI wrappers around the Spatialite C library. The Spatialite wrappers were derived and adapted from the platform SQLite wrappers (the standard Android SQLite API).

Other FAQ

What is Spatialite?

Simply: Spatialite = SQLite + advanced geospatial support.
Spatialite is a geospatial extension to SQLite. It is a set of few libraries written in C to extend SQLite with geometry data types and many SQL functions above geometry data. For more info: https://www.gaia-gis.it/gaia-sins/

Does it use JDBC?

No. It uses cursors - the suggested lightweight approach to access SQL used in the Android platform instead of the heavier JDBC.

64-bit architectures supported?

Yes. It builds for arm64-v8a and x86_64. mips64 is not tested.

Reducing the APK size.

This library is distributed as multi-architecture AAR file. By default Gradle will produce a universal APK including the native .so libraries compiled for all supported CPU architectures. Usually that's unacceptable for large libraries like this. But that's easily fixed by using Gradle's "ABI splits" feature. The following gradle code will produce a separate APK per each architecture. The APK size is reduced few times.

android {
    splits {
        abi {
            enable true
                reset()
                include "armeabi-v7a", "arm64-v8a", "x86", "x86_64"
            }
        }
    }
}

What libraries are packaged currently?

  • SQLite 3.15.1
  • Spatialite 4.3.0a
  • GEOS 3.4.2
  • Proj4 4.8.0
  • lzma 5.2.1
  • iconv 1.13
  • xml2 2.9.2
  • freexl 1.0.2

REQUIREMENTS

Min SDK 15

MIGRATION TO 2.0+

  1. Remove calls to SQLiteDatabase.loadLibs(). Now it is automatically done.
  2. Replace all occasions of import org.spatialite.Cursor; with import android.database.Cursor;
  3. Replace all occasions of import org.spatialite.database.SQLite***Exception; with import android.database.sqlite.SQLite***Exception;

CHANGES

2.0.0

  • Now using the Requery.io SQLite wrapper instead of SQLCipher's. This results to:
  • Android Nougat (25+) supported. The native code no more links to private NDK libraries exception and warning messages similar to UnsatisfiedLinkError: dlopen failed: library "libandroid_runtime.so" not found should be no more. For more details: https://developer.android.com/about/versions/nougat/android-7.0-changes.html#ndk;
  • Much cleaner codebase derived from a much newer and more mature AOSP SQLite wrapper snapshot;
  • Now possible to build with the latest NDK (tested on R14);
  • Switched to CLang as the default NDK toolchain;
  • 64-bit build targets (arm64-v8a, x86_64);
  • SQLiteDatabase.loadLibs() initialization call is not required anymore;
  • Removed org.spatialite.Cursor interface. Used 'android.database.sqlite.Cursor' instead.
  • Removed the SQLiteXyzException classes. Their AOSP originals are used instead;
  • Dropped support for Android localized collation. SQL statements with "COLLATE LOCALIZED" will cause error. This is necessary to reduce the library size and ensure N compatibility;
  • Updated SQLite to 3.15.1;
  • Updated lzma to 5.2.1;
  • Updated FreeXL to 1.0.2;

CREDITS

The main ideas used here were borrowed from:

LICENSE

Apache License 2.0