Java Question how to be,with import . jar file

[hears]

when make library,the project depend on .jar SDK file

in eclipse code import many VOID in this
.jar
i have finish make my library.
in B4A project, i must import this .jar file too?

how to import?

 

[hears]

i have make libary ,but when use this libary have this erro:

java.lang.NoClassDefFoundError: com.zj.usbsdk.UsbController

"usbsdk "in another SDK .jar file ,how to import this file in b4a project ?

 

[hears]

i find this code put in eclips project,after copy .jar file to B4A library folder...

import anywheresoftware.b4a.BA.DependsOn;
@DependsOn(values={"usbsdk"})
i think .jar no problem now...

package cn.com.zj.usbdemo;

import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.sql.Date;
import java.text.SimpleDateFormat;

import zj.com.customize.sdk.Other;
import com.zj.command.sdk.Command;
import com.zj.command.sdk.PrintPicture;
import com.zj.command.sdk.PrinterCommand;
import cn.com.zj.usbdemo.R;
import com.zj.usbsdk.UsbController;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.hardware.usb.UsbDevice;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.RadioButton;
import android.widget.Toast;
import anywheresoftware.b4a.BA.ShortName;

import anywheresoftware.b4a.BA.DependsOn;



@ShortName("printdemo")
@DependsOn(values={"usbsdk"})

public class PrintDemo extends Activity implements OnClickListener{

i use this code get library again.
when use in b4a ,have this erro.
java.lang.NullPointerException

why ?


erro from this function

import com.zj.usbsdk.UsbController;
 static UsbController  usbCtrl = null;

usbCtrl = new UsbController(this,mHandler);



public void connectusb (){
        usbCtrl.close();
        int  i = 0;
        for( i = 0 ; i < 8 ; i++ ){
            dev = usbCtrl.getDev(u_infor[i][0],u_infor[i][1]);
            if(dev != null)
                break;
        }

        if( dev != null ){
            if( !(usbCtrl.isHasPermission(dev))){
               
                usbCtrl.getPermission(dev);
            }else{
               
               
               
               
            }
        }

       
    }



@SuppressLint("HandlerLeak") private final  Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case UsbController.USB_CONNECTED:
                Toast.makeText(getApplicationContext(), getString(R.string.msg_getpermission),
                        Toast.LENGTH_SHORT).show();
                btnSend.setEnabled(true);
                btn_test.setEnabled(true);
                btnClose.setEnabled(true);
                btn_printA.setEnabled(true);
                btn_BMP.setEnabled(true);
                btn_ChoseCommand.setEnabled(true);
                btn_prtcodeButton.setEnabled(true);
                btn_prtsma.setEnabled(true);
                btn_prttableButton.setEnabled(true);
                Simplified.setEnabled(true);
                Korean.setEnabled(true);
                big5.setEnabled(true);
                thai.setEnabled(true);
                btn_conn.setEnabled(false);
                break;
            default:
                break;
            }
        }
    };

 

[Erel]

Don't wrap full activities. It will make things more complicated.

java.lang.NullPointerException

why ?

Can you post the full error message?

 

[hears]

Don't wrap full activities. It will make things more complicated.


Can you post the full error message?

main_button7_click (java line: 995)
java.lang.IllegalStateException: System services not available to Activities before onCreate()
at android.app.Activity.getSystemService(Activity.java:4532)
at com.zj.usbsdk.UsbController.<init>(UsbController.java:40)
at cn.com.zj.usbdemo.PrintDemo.connectusb(PrintDemo.java:1039)
at b4a.example1.main._button7_click(main.java:995)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:186)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:170)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:166)
at anywheresoftware.b4a.objects.ViewWrapper$1.onClick(ViewWrapper.java:80)
at android.view.View.performClick(View.java:4443)
at android.view.View$PerformClick.run(View.java:18443)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5009)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:811)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:627)
at dalvik.system.NativeStart.main(Native Method)

BA myba;
        
         public void initialize(BA ba) // ba is a hidden parameter
            {
              myba = ba; //save it if you need to
              Activity a = myba.activity; // get the Activity
           h = new Handler(); // get a handler for the current thread 
            
            }
        
         public void connectusb (){

                //        onCreate(null, null);
//                usbCtrl.close();
                
                usbCtrl = new UsbController(this,h);
                u_infor = new int[8][2];
                u_infor[0][0] = 0x1CBE;
                u_infor[0][1] = 0x0003;
                u_infor[1][0] = 0x1CB0;
                u_infor[1][1] = 0x0003;
                u_infor[2][0] = 0x0483;
                u_infor[2][1] = 0x5740;
                u_infor[3][0] = 0x0493;
                u_infor[3][1] = 0x8760;
                u_infor[4][0] = 0x0416;
                u_infor[4][1] = 0x5011;
                u_infor[5][0] = 0x0416;
                u_infor[5][1] = 0xAABB;
                u_infor[6][0] = 0x1659;
                u_infor[6][1] = 0x8965;
                u_infor[7][0] = 0x0483;
                u_infor[7][1] = 0x5741;
//                int  i = 0;
//                for( i = 0 ; i < 8 ; i++ ){
//                    dev = usbCtrl.getDev(u_infor[i][0],u_infor[i][1]);
//                    if(dev != null)
//                        break;
//                }
        //
//                if( dev != null ){
//                    if( !(usbCtrl.isHasPermission(dev))){
//                       
//                        usbCtrl.getPermission(dev);
//                    }else{
//                       
//                       
//                       
                        
            //        }
                //}

                
            }

 

[hears]

erro from here
usbCtrl = new UsbController(this,h);

 

[Erel]

The problem is that you wrapped the code as an activity. The only way to create activities is by starting them with StartActivity.

It will be simple to wrap a regular class instead.

 

[hears]

The problem is that you wrapped the code as an activity. The only way to create activities is by starting them with StartActivity.

It will be simple to wrap a regular class instead.

it is work now .
usbCtrl = new UsbController(this,h);

i just add these code

BA myba;
public void initialize(BA ba) // ba is a hidden parameter
         {
           myba = ba; //save it if you need to
           Activity a = myba.activity; // get the Activity
        h = new Handler(); // get a handler for the current thread
     
         }

and the erro code,i change to usbCtrl = new UsbController(myba.activity,h);


i understand now : in JAVA CODE "this" need change to BA.activity . "handler "need get from this initialize(BA ba) function