Android Tutorial [java] Creating libraries for B4A

emresensoy · Jan 26, 2013

i did all things but there is no jar file, only xml file;

B4X:

<?xml version="1.0" encoding="UTF-8"?>
<root>
    <doclet-version-NOT-library-version>1.02</doclet-version-NOT-library-version>
    <class>
        <name>b4a.deneme.DenemeLib</name>
        <shortname>DenLib</shortname>
        <owner>process</owner>
        <method>
            <name>mul</name>
            <comment></comment>
            <returntype>int</returntype>
            <parameter>
                <name>x</name>
                <type>int</type>
            </parameter>
        </method>
    </class>
</root>

Erel · Jan 27, 2013

I guess that you followed the video tutorial. It misses the export to jar step. It is explained in the video tutorial forum thread.

socialnetis · Mar 10, 2013

I'm algo having a "No class def found". And I have set the Eclipse project configuration Java compiler compliance to Java 1.6.

In a package I can have 2 or more classes, do I need to put "@ShortName("somename")" to every class right? Is there a problem if the shortname matches the class name?

agraham · Mar 10, 2013

A package can have more than one class. The classes can either be in separate .java files or can be static classes within a single main class in a single .java file.

You need an @ShortName("somename") annotation on each class that you want exposed to Basic4android. the name can be whatever you want.

Note that if you have more than .java file when you do Project -> Generate Javadoc if your package shows a filled in square and not a tick then not all .java files are selected and the missing ones will not be included in the xml. You will need to click the box until it shows a tick.

socialnetis · Mar 11, 2013

What am I doing wrong?

I want to make a little library to access some functions of the Telephony library.

Here is my b4a code:

B4X:

Sub Globals
   Dim t As Telephony
End Sub

Sub Activity_Create(FirstTime As Boolean)
   'Activity.LoadLayout("Layout1")
   Dim l As List
End Sub

I'm not even using the telephony object and I get this error:

main_globals (java line: 266)

java.lang.NoClassDefFoundError: socialnetis.telephony.SNTelephony

at b4a.example.main._globals(main.java:266)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:167)
at b4a.example.main.initializeGlobals(main.java:222)
at b4a.example.main.afterFirstLayout(main.java:82)
at b4a.example.main.access$100(main.java:16)
at b4a.example.main$WaitForLayout.run(main.java:72)
at android.os.Handler.handleCallback(Handler.java:605)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4611)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
at dalvik.system.NativeStart.main(Native Method)

This are the Java files:
SNTelephony.java:

B4X:

package socialnetis.telephony;

import android.content.Context;
import android.telephony.NeighboringCellInfo;
import android.telephony.TelephonyManager;
import anywheresoftware.b4a.BA;
import anywheresoftware.b4a.objects.collections.List;
import anywheresoftware.b4a.BA.ShortName;
import anywheresoftware.b4a.BA.Version;

@ShortName("Telephony")
@Version(1.0f)

public class SNTelephony {

   public List getAllCellInfo(final BA ba) {
      TelephonyManager t = (TelephonyManager)ba.context.getSystemService(Context.TELEPHONY_SERVICE);
      List l;
      l = new List();
      l.Initialize();
      for (NeighboringCellInfo n : t.getNeighboringCellInfo()) {  
         SNNeighboringCellInfo s;
         s = new SNNeighboringCellInfo();
         s.Initialize(n);
         l.Add(s);
      }
      return l;
    }
}

SNNeighboringCellInfo.java:

B4X:

package socialnetis.telephony;

import android.telephony.NeighboringCellInfo;
import anywheresoftware.b4a.BA.ShortName;

@ShortName("NeighboringCellInfo")

public class SNNeighboringCellInfo {
   NeighboringCellInfo n;

   public void Initialize(NeighboringCellInfo ncf) {
      n = ncf;
   }
   public int getCid () {
      return n.getCid();
   } 
      
   public int getRssi () {
      return n.getRssi();      
   }
}

I do mark with a tick when I want to make the javadoc, and the .jar and .xml files are in the AddLibraries.

What am I missing?

EDIT:
The project had to target Java 6 (Project-Propertis-Java).
What I did before was Windows-preferences-Java and taget java 6

agraham · Mar 11, 2013

I've just built a library by cutting and pasting your code and it compiles and creates a Telephony instance just fine. I can't immediately think of something that would let the Class be used at compile time but fail to find it at run time. I've attached my version for you to try.

jalle007 · Mar 11, 2013

Eclipse is telling me that it can't find BADoclet class althouh I set it like from the manual

any idea ?

socialnetis · Mar 11, 2013

agraham said:
I've just built a library by cutting and pasting your code and it compiles and creates a Telephony instance just fine. I can't immediately think of something that would let the Class be used at compile time but fail to find it at run time. I've attached my version for you to try.

Hey, thanks for answering, It was a problem with JDK 7, i needed to use JDK 6 in the project to compile. Now it works

socialnetis · Mar 11, 2013

jalle007 said:
Eclipse is telling me that it can't find BADoclet class althouh I set it like from the manual

any idea ?

If you put the doclet under the C hard disk, you should only put "c:\" in the path

jalle007 · Mar 12, 2013

OK that helped. but still no success.
here is output from Eclipse

B4X:

Loading source files for package anywheresoftware.b4a.sample...
Constructing Javadoc information...
[-doclet, BADoclet]
[-docletpath, c:\Users\xxx\Dropbox\_ANDROID\B4A\BADoclet\]
[-sourcepath, C:\Users\xxx\workspace\TestLib\src]
[-classpath, C:\Users\xxx\AppData\Local\Android\android-sdk\platforms\android-8\android.jar;C:\Program Files (x86)\Anywhere Software\Basic4android\Libraries\Core.jar;C:\Program Files (x86)\Anywhere Software\Basic4android\Libraries\B4AShared.jar]
[-public]
[-b4atarget, c:\Users\xxx\Dropbox\_ANDROID\B4A\_JAVA\TestLib.xml]
starting....
Working with class: anywheresoftware.b4a.sample.TestLib
warning: no version field.
finish: c:\Users\xxx\Dropbox\_ANDROID\B4A\_JAVA\TestLib.xml

I have TestLib.xml
but no TestLib.jar

any idea ?

agraham · Mar 12, 2013

See post #42 above.

jalle007 · Mar 12, 2013

agraham said:
See post #42 above.

Yes that solved the issue. Now I have my 1st java library build :sign0137:

lorebarita · Apr 4, 2013

Error:

I am getting the following error after i have loaded the library to b4a and i try to use it. Please help:sign0085:

java.lang.NoClassDefFoundError: anywheresoftware.b4a.sample.CardReader

at anywheresoftware.b4a.sample.main._globals(main.java:331)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:167)
at anywheresoftware.b4a.sample.main.initializeGlobals(main.java:222)
at anywheresoftware.b4a.sample.main.afterFirstLayout(main.java:82)
at anywheresoftware.b4a.sample.main.access$100(main.java:16)
at anywheresoftware.b4a.sample.main$WaitForLayout.run(main.java:72)
at android.os.Handler.handleCallback(Handler.java:587)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
at dalvik.system.NativeStart.main(Native Method)

Erel · Apr 4, 2013

Please start a new thread for this question.

PhilipBrown · May 3, 2013

Compile to Library

Please forgive my ignorance but how does the Project menu option "Compile to Library" fit in with all this? I can't find it mentioned here anywhere.

Erel · May 3, 2013

There are two ways to build libraries. You can compile modules from your project into a library (new feature in v2.50) or you can write the code in Java and follow the instructions in this thread.

With Java written libraries you can add features that are otherwise not accessible.

hanyelmehy · May 11, 2013

how to run :
AndroidSDKProvider.initSDK(this);
what is equivalent for (this)

Erel · May 12, 2013

We can only guess without seeing the documentation of this method...

ebalvis · May 13, 2013

Lib fail

I am making a library for use printers star.
When I try to run the application I get the following error and the application closes.
I'm using in eclipse, JRE System Library [jdk1.6.0_26]

main_process_globals (java line: 329)

java.lang.VerifyError: innebo/ioport/printer/IOPortLib

at b4a.example.main._process_globals(main.java:329)
at b4a.example.main.initializeProcessGlobals(main.java:299)
at b4a.example.main.afterFirstLayout(main.java:85)
at b4a.example.main.access$100(main.java:16)
at b4a.example.main$WaitForLayout.run(main.java:74)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4898)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
at dalvik.system.NativeStart.main(Native Method)

agraham · May 13, 2013

For a library you need to reference one of the Android android.jar files from the SDK. You can delete the JRE System Library from your project Build Path. You don't need it.

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