How can I call a non-static method of a java class from c ++?

[Blaster]

Let's see, in an android application that I'm doing I'm trying to get the device IMEI. In my java class I have something like this:

package cu.cibertools.regcharge.fetch;

import android.provider.ContactsContract;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.content.Intent;
import android.telephony.TelephonyManager;


public class FetchClass extends org.qtproject.qt5.android.bindings.QtActivity
{

    public FetchClass()
    {
    }

    public String getIMEI1()
    {
        String srvcName = Context.TELEPHONY_SERVICE;
        TelephonyManager phone = (TelephonyManager)getSystemService(srvcName);
        String deviceId = phone.getDeviceId();
        return deviceId;
    }

}

In my c ++ class I have:

QString BackEnd::getIMEI()
{
    bool avail = QAndroidJniObject::isClassAvailable("cu/cibertools/regcharge/fetch/FetchClass");
    QAndroidJniObject clase("cu/cibertools/regcharge/fetch/FetchClass");
    QString imei;
    QAndroidJniObject imeiCode;

    if (avail && clase.isValid())
    {
       imeiCode = clase.callObjectMethod("obtenerImei", "()Ljava/lang/String;");
       qDebug()<<"IMEI RETURN:"<<imeiCode.toString();
    }
    else
    {
       qDebug() << "IMEI NOT AVAILABLE";
    }
    return imeiCode.toString();

}

But in the debug messages I do not get anything ... the value of imeiCode.toString () is empty. In a moment I replaced all the contents of the function getIMEI () of the java class and placed only return "Some Text"; and nothing. Can you tell me what I'm doing wrong?

[Blaster]

Researching I found this:

QAndroidJniObject java("cu/cibertools/regcharge/fetch/FetchClass");
        QAndroidJniObject imeiNum = java.callMethod<jstring>("obtenerImei", "(V)Ljava/lang/String;");
        QString imei = imeiNum.toString();

        qDebug()<<"IMEI:"<<imei;
        return imei;

but it gives me the following error.

error: ld returned 1 exit status
File not found: collect2.exe

[Blaster]

I finally resolved. I replace:

QAndroidJniObject java("cu/cibertools/regcharge/fetch/FetchClass");
        QAndroidJniObject imeiNum = java.callMethod<jstring>("obtenerImei", "(V)Ljava/lang/String;");
        QString imei = imeiNum.toString();

        qDebug()<<"IMEI:"<<imei;
        return imei;

for

QtAndroid::runOnAndroidThread([] {
        QAndroidJniObject java("cu/cibertools/regcharge/fetch/FetchClass");
        QAndroidJniObject imeiNum = java.callObjectMethod("obtenerImei", "(Landroid/content/Context;)Ljava/lang/String;",
                                                          QtAndroid::androidActivity().object<jobject>());
        QString imei = imeiNum.toString();

        qDebug()<<"IMEI:"<<imei;
        return imei;
    });

And in java class:

private String obtenerImei(Context c) {

        String imei = "352319065579474";
        TelephonyManager tm = (TelephonyManager)c.getSystemService(Context.TELEPHONY_SERVICE);
        imei =tm.getDeviceId(); // Obtiene el imei  or  "352319065579474";

        if(imei == "")
            imei = "NO getDeviceId";
        return imei;

    }

[Blaster]

Well ... I retract .. that only works sometimes ... can someone tell me what is going on?

[ambershark]

@Blaster Is your QAndroidJniObject valid? What is the result of imeiNum.isValid()?

[Blaster]

Yes, now is for real. I solved.

QString imei;
QtAndroid::runOnAndroidThreadSync([&imei] {
        QAndroidJniObject java("cu/cibertools/regcharge/fetch/FetchClass");
        QAndroidJniObject imeiNum = java.callObjectMethod("obtenerImei", "(Landroid/content/Context;)Ljava/lang/String;",
                                                          QtAndroid::androidActivity().object<jobject>());
        imei = imeiNum.toString();
    });
return imei;

I just change runOnAndroidThread for runOnAndroidThreadSync and is it;