miniJVM

Develop iOS Android app in java, Cross platform java virtual machine , the minimal jvm .

Features:

Jvm Build pass: iOS / Android / mingww64 32-64bit / cygwin / MSVC 32-64bit / MacOS / Linux .
No dependence Library .
Minimal memory footprint .
Minimal binary, embedded jvm.
Minimal runtime classlib .
Support java5+ class file .
Support embedded java source compiler(janino compiler) .
Java native method .
Java garbage collection .
Java remote debug supported, JDWP Spec .

iOS/Android Platform Extended Features:

OpenGL ES 3.0 .
Swing like gui .
Audio Playback and Capture .
Take photo from Camera or Album .
Save and Load file from mobile storage .
Api compatible with miniJVM desktop platform, can running on pc .

mobile app IM Demo BiBiX , source at :https://github.com/digitalgust/BiBiX

This demo can be download from : http://bb.egls.cn:8080/down/BiBiX.jar , First install AppManager from : /binary/ios/MiniPack.ipa or /binary/android/MiniPack.apk ,or run AppManager in mini_jvm (eg. /binary/win_64) then download demo in AppManager and run the app.

Architecture:

How to develop iOS/Android app in java:

Write java code once , running on all of iOS / Android / MacOSX / Win / Linux platforms.

Can develop app by Eclipse, Netbeans or Intelli Idea , or any IDE .
Build maven projects /minijvm/java and /mobile/java/glfm_gui, it world copy generated jar to /mobile/assets/resfiles/minijvm_rt.jar and /mobile/assets/resfiles/glfm_gui.jar
Open maven project ExApp in IDE ,or create new project same as ExApp
Write your code like example /mobile/java/ExApp/src/main/java/test/MyApp.java
Add your resource to /mobile/java/ExApp/src/main/resource/res/ , such as audio or image etc.
Configure /mobile/java/ExApp/src/main/config.txt for icon ,version, boot class, etc .
Build ExApp project , it would copy ExApp.jar to /mobile/assets/resfiles/ExApp.jar
Install /binary/ios/MiniPack.ipa for iPhone device , (Enterprise distrbute version, need Verify app, Setting->General->Device Management->EGLS Technology ltd->Verify App), or /binary/android/MiniPack.apk for Android device , These two binary built from /mobile/iosapp/ and /mobile/java/androidapp, you can build it yourself.
Touch the app icon to open MiniPack app, you would see the ExApp is running (the left of picture). You can touch "exit to AppManager" in ExApp, AppManager is a App maintaince tool (the middle and right of picture), It can start a in-app webserver for upload app, it can download app from a website also .

How to Remote debug:

Prepare: Rebuild /minijvm/c ,change /minijvm/c/jvm/jvm.h "#define JDWP_DEBUG 0" as "#define JDWP_DEBUG 1" Desktop Computer : Run mini_jvm with flag: -Xdebug for debug mode .
iOS/Android simulator : nothing to do .
iOS/Android device : check the device ip address from General Setting -> wifi ->(i).
mini_jvm jdwp listen port is 8000.

Intelli idea : open the java project , menu Run .> Edit Configurations , + remote , Transport : socket , Debugger mode : attach , host is your mini_jvm running at host ip and port ,ex. "localhost:8000" .
Eclipse : configuration like as idea .
Netbeans : open java project , menu Debug .> connect to Debugger, Connector : SocketAttach , host is your mini_jvm running at the host and port, ex. "localhost:8000" , Timeout: 10000 .
Then you can setup breakpoint or pause mini_jvm and watch variable's value .

How to use Embed java compiler in mini_jvm:

Java Compiler : /binary/libex/janino.jar
Usage of compiler can be found in /binary folder
the compile command :

win:
mini_jvm -cp ../lib/minijvm_rt.jar;../libex/janino.jar;../libex/commons-compiler.jar org.codehaus.janino.Compiler  ../res/BpDeepTest.java
posix:
./mini_jvm -cp ../lib/minijvm_rt.jar:../libex/janino.jar:../libex/commons-compiler.jar org.codehaus.janino.Compiler  ../res/BpDeepTest.java

Janino compiler is not the full java compiler, see limitation , like :

List<String> list=new ArrayList(); 
list.add("abc");
String s=(String)list.get(0);//can't ignore (String) cast qualifier.

Referenced project and technology:

Sun CLDC :reference
Miniz :for read jar files
GLFM :for cross platform (android/ios) GUI
Nanovg :for GUI paint function
Stb :for GUI truetype font and image
Glad :for replace openGL/GLES head file
GLFW :for pc cross platform GUI
Dirent :for linux style on win vc file and directory access
Tinycthread :for cross platform thread
JRegex :for java String regex match
Janino :for compile java source file
MiniAudio :for java audio playback and capture

Development IDE using:

C code: JetBrains CLion ,Xcode ,Virtual studio .
Swift code/Object c: XCode , LLVM .
Java code: Netbeans ,jdk .
android project: Android Studio , Android SDK

Build GUI application, depend on openGL or openGLES

iOS/Android system build with GLFM (/mobile/iosapp/ , /mobile/androidapp/)
Window system build with GLFW (/desktop/glfw_gui/)
GUI build with Nanovg

Example of mobile application

the example demonstrate how develop java app for iOS and Android

package test;

import org.mini.apploader.AppManager;
import org.mini.gui.*;
import org.mini.gui.event.*;

/**
 *
 * @author gust
 */
public class MyApp extends GApplication {

    GForm form;
    GMenu menu;
    GFrame gframe;

    @Override
    public GForm getForm(GApplication appins) {
        if (form != null) {
            return form;
        }
        GLanguage.setCurLang(GLanguage.ID_CHN);
        form = new GForm();

        form.setFps(30f);
        long vg = form.getNvContext();

        int menuH = 80;
        GImage img = GImage.createImageFromJar("/res/hello.png");
        menu = new GMenu(0, form.getDeviceHeight() - menuH, form.getDeviceWidth(), menuH);
        menu.setFixed(true);
        GMenuItem item = menu.addItem("Hello World", img);
        item.setActionListener(new GActionListener() {
            @Override
            public void action(GObject gobj) {
                if (gframe != null) {
                    gframe.close();
                }
                gframe = getFrame1();
                form.add(gframe);
                gframe.align(GGraphics.HCENTER | GGraphics.VCENTER);
            }
        });

        img = GImage.createImageFromJar("/res/appmgr.png");
        item = menu.addItem("Exit to AppManager", img);
        item.setActionListener(new GActionListener() {
            @Override
            public void action(GObject gobj) {
                AppManager.getInstance().active();
            }
        });

        form.add(menu);
        return form;
    }

    public GFrame getFrame1() {

        GFrame gframe = new GFrame("Hello World", 50, 50, form.getDeviceWidth() * .8f, (form.getDeviceHeight() - menu.getH()) * .7f);
        GViewPort parent = gframe.getView();
        float pad = 8;
        float x = pad, y = 10;
        float btnH = 28;

        String conttxt = "  This app is an example of mini_jvm, Threre are a menu and a frame .\n"
                + "  Touch the 'Exit to AppManager' , you will enter the AppManager, AppManager manage all app, it can upload ,download , delete app.\n"
                + "  1. DOWNLOAD : Put your jar in a website , then input the url of jar in AppManager, Touch 'Download' ,it would download the jar ,then update the app list.\n"
                + "  2. UPLOAD : The first you touch the 'Start' to open the inapp webserver, then open browser in your Desktop Computer, open 'http://phone_ip_addr:8088' , and pickup a jar in the page, upload it.  NOTE: That computer and the phone must be same LAN.\n"
                + "  3. RUN : Touch the App name in the list, Touch 'Run' can start the app.\n "
                + "  4. SET AS BOOT APP : The boot app will startup when MiniPack opend. \n"
                + "  5. UPGRADE : AppManager will download the new jar ,url that get from config.txt in jar.\n"
                + "  6. DELETE : The app would be deleteted.\n";
        GTextBox cont = new GTextBox(conttxt, "Contents", x, y, parent.getW() - x * 2, parent.getH() - pad * 2 - btnH - y);
        cont.setEditable(false);
        parent.add(cont);
        y += cont.getH() + pad;

        GButton bt2 = new GButton("Cancel", x + 170, y, 110, btnH);
        bt2.setBgColor(0, 0, 0, 0);
        bt2.setActionListener(new GActionListener() {
            @Override
            public void action(GObject gobj) {
                gobj.getForm().remove(gframe);
            }
        });
        parent.add(bt2);

        return gframe;
    }

}

Screen shot :

Windows mini_jvm gui

* Macos mini_jvm gui

* Linux mini_jvm gui

Directories:

/

binary/-------- minijvm binary (win32/win64/mac/linux/android/ios)
minijvm/

c/------------ minijvm c source
java/--------- minijvm runtime library

desktop/

glfw_gui/------ desktop computer gui/audio native module

mobile/

c/------------- java native lib, glfm framework, gui jni, glfmapp
java/glfm_gui-- mobile platform native gui lib
java/ExApp----- java app entry point
iosapp/-------- iOS launcher
androidapp/---- Android launcher
assets/resfiles/- mobile app resource, font files, jar files ,pic ,audio etc.

test/

jvm_ios/------ ios swift test project .
jvm_macos/---- macosX test project.
jvm_vs/------- windows virtual studio test project.
jni_test/------ jni example
javalib_test/-- test case of /minijvm/java .

/minijvm/c is an independent small and fast jvm interpreter, it run on Win/Mac/Linux/iOS/Android.
/minijvm/java is the jvm foundation runtime library, ex java.lang , java.util ,and extended classes org.mini for file,reflect and network etc, this project generate minijvm_rt.jar .
/mobile/iosapp /mobile/androidapp are iOS/Android launcher program, it include minijvm source and native function, java call gui library with jni.
/mobile/java/glfm_gui is a gui library ,it dependent on native gui library ,that include openGLES glad, glfm, nanovg, stb lib etc , this project generate glfm_gui.jar .
/mobile/java/ExApp is an example of mobile app, it run on iOS and Android platform.

License

License: Public domain

Gust , zhangpeng@egls.cn , Technology and production manage in EGLS ltd. EGLS is a game develop company in China .

jbg168 / miniJVM