java.cr
Java Native Interface (JNI) bindings (and generator) for Crystal
Generate Java bindings through the Java Native Interface (JNI) automatically from Java classes using the javap
tool distributed with the JDK.
The main goal is to generate bindings for the Android SDK. This project is thus for the most usable widget and communication classes (e.g. android.app.Activity
, android.os.Handler
or android.widget.TextView
). More complex classes, mostly those relying on generics and wildcards will probably fail, or generate invalid Crystal code.
Install
Add the shard to your shard.yml
dependencies:
dependencies:
java:
github: ysbaddaden/java.cr
Usage
Let's generate some bindings for an Android project. First we must add the target platform android.jar
to CLASSPATH
. For example. Let's also add the project local folder where the Android SDK will store the compiled classes.
export CLASSPATH=bin/classes:/opt/android-sdk/platforms/android-23/android.jar
Let's generate some bindings, this will load the definition of the specified classes, potentially following classes found, then generate the Crystal bindings into namespace separated folders. Pass --help
for the full list of options.
lib/java/bin/generator --output src --no-follow \
android.app.Activity \
android.os.Bundle \
android.os.Message \
android.os.Handler
You may now just use it:
require "android/os/bundle"
require "android/os/message"
bundle = Android::Os::Bundle.new
bundle.put_char_sequence("action", "setText")
bundle.put_char_sequence("text", "hello world")
message = Android::Os::Message.new
message.set_data(bundle)
TODO
- fix bugs
- write tests
Authors
- Julien Portalier (creator, maintainer)
java.cr
- 23
- 1
- 1
- 1
- 1
- over 7 years ago
- December 25, 2016
Sat, 04 May 2024 03:11:49 GMT