Error when calling pure java code (separate project) from android in eclipse

Question

I have this simple java code:

package com.androiddesktoptest.testtest;

public class AndroidDesktopTestMain
{
    public static void main(String[] args)
    {
        callFromAndroid();
    }

    public static void callFromAndroid()
    {
        System.out.println("DESKTOP CODE CALLED FROM ANDROID");
    }
}

And I want to call it from Android like this:

import com.androiddesktoptest.testtest.AndroidDesktopTestMain;

public void onCreate(Bundle savedInstanceState)
{
    //...
    AndroidDesktopTestMain.callFromAndroid();
}

and I get java.lang.NoClassDefFoundError

I am using Eclipse and my project AndroidDesktopTest has checked to export AndroidDesktopTest/src. Also, eclipse autocomplete my code in Android, so it see correcly my code in desktop project.

What I am doing wrong? I did something like this in my previous-previous-previous project, from this time, maybe ADT has chaged or something...

* UPDATE * entire error 07-20 14:02:56.452: E/AndroidRuntime(30233): java.lang.NoClassDefFoundError: com.androiddesktoptest.testtest.AndroidDesktopTestMain

07-20 14:02:56.452: E/AndroidRuntime(30233): java.lang.NoClassDefFoundError: com.androiddesktoptest.testtest.AndroidDesktopTestMain — SuitUp, Jul 20 '12 at 12:31
Anders Metnik - one project export source, and second (Android) has java project in "required project in the build path". Is it enough? — SuitUp, Jul 20 '12 at 12:57

score 3 · Answer 1 · answered Jul 20 '12 at 13:31

Order & Export isn't the most well built feature of the Android ADT.

If you instead include the linked src folder from the Desktop project to your Android project (Right Click Project > Build Path > Link Source Folder) then the Class will be used as if it belongs to the Android Project.

I think the prefered way of doing this would be to create a jar file or a Library Project but these might be too cumbersome to try until you have stable Deskptop code.

Hope that helps!

score 2 · Accepted Answer · answered Jul 20 '12 at 12:47

2

Sounds like you don't get the class over to the phone when u run your android.

Make sure that:

right click project - properties - java build path - Order and Export (is it checked here?)

answered Jul 20 '12 at 12:47

Anders Metnik

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In order and export, move up your external project so it is almost at the top (right under your android project). – Anders Metnik Jul 20 '12 at 12:59
I think he is referring to the precedence of the library export order. – Graeme Jul 20 '12 at 13:33
src is at the top from the beginnning – SuitUp Jul 20 '12 at 13:39
And after that needs to be your java project, else it won't reference it right when you load it onto the device. – Anders Metnik Jul 23 '12 at 07:39
Else attach a screenshot of it (the export order). And I can explain it out from that. – Anders Metnik Jul 23 '12 at 13:11
If it is unclear for anyone: you must export desktop code in desktop project AND android project. – SuitUp Jul 23 '12 at 15:28

score 0 · Answer 3 · answered Jul 20 '12 at 13:34

0

This article about including Java libraries into Android projects suggests replacing the "JRE System Library" with the android.jar for your API level in your linked Java project's build path dialog.

answered Jul 20 '12 at 13:34

Jan Gerlinger

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score -1 · Answer 4 · answered Jul 20 '12 at 12:41

-1

try this

new AndroidDesktopTestMain.callFromAndroid();

The only way to call a non-static method from a static method is to have an instance of the class containing the non-static method. By definition, a non-static method is one that is called ON an instance of some class, whereas a static method belongs to the class itself.

answered Jul 20 '12 at 12:41

MicroEyes

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What? public static void callFromAndroid() – SuitUp Jul 20 '12 at 12:50
I m not getting you.. Have you tried the above code? Is it working? – MicroEyes Jul 20 '12 at 12:52
callFromAndroid is static, so I don't understand your answer... and yes, I tried it (look at another answer, same strange advice). – SuitUp Jul 20 '12 at 12:58

Error when calling pure java code (separate project) from android in eclipse

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