how to call a Method of a class kept under other package

Question

I am a beginner in Android Developing. Can any1 please guide me how to call a Method of a class kept under other package.

Like class A in Package 1 calls a method in Class B of Package 2 which returns An array or object.

Do i have to create an Intent for that?? actually i have to gather all information in 1 class from different classes kept under different packages.

Thanks in advance.

package com.xyz.Master;


import android.app.Activity;
import android.content.Context;
import android.os.Build;
import android.telephony.CellLocation;
import android.telephony.TelephonyManager;
import android.telephony.gsm.GsmCellLocation;

public class PhoneInfo extends Activity {

TelephonyManager tm = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
GsmCellLocation location = (GsmCellLocation) tm.getCellLocation();  
public int cellID, lac,mcc,mnc;
public String imei,manufacturer,model,product;
String[] phoneInfo;
int[] phoneLocationInfo;    

public String[] getHandsetInfo()
{
    manufacturer = Build.MANUFACTURER;
    model = Build.MODEL;
    product = Build.PRODUCT;
    imei=tm.getDeviceId();        

    String softwareVersion = tm.getDeviceSoftwareVersion();

    phoneInfo = new String[5];
    phoneInfo[0]=imei;
    phoneInfo[1]=product;
    phoneInfo[2]=model;
    phoneInfo[3]=manufacturer;
    phoneInfo[4]=softwareVersion;
    return phoneInfo;

}
public int[] getHandsetLocationInfo()
{
    phoneLocationInfo= new int[4];
    String networkOperator = tm.getNetworkOperator();
     if (networkOperator != null) {
            mcc = Integer.parseInt(networkOperator.substring(0, 3));
            mnc = Integer.parseInt(networkOperator.substring(3));
      }
     CellLocation.requestLocationUpdate(); 
     cellID = location.getCid();
     lac = location.getLac();

     phoneLocationInfo[0]=cellID;
     phoneLocationInfo[1]=lac;
     phoneLocationInfo[2]=mcc;
     phoneLocationInfo[3]=mnc;

     return phoneLocationInfo;

}
}

I want to call above methods from other class and get these arrays. How to do that, is there any error in above code??

Answer 1

Assuming, we're talking about the Java package, then we have several rules for calling methods on classes in other packages. To keep it simple, this works:

package com.example.one;
public class ArrayProvider {
  public String[] getArray() {
    return new String{"I'm ","inside ", "an ", "array "};
  }
  public static Object getObject() {
    return new String{"I'm ","inside ", "an ", "array "};
  }
}

Now your code to access the methods of class ArrayProvider from the other package:

package my.namespace.app;
import com.example.one.ArrayProvider;      // import the other class

public class MyClass {

  public static void main(String[] args) {

    // to access the static method
    Object result1 = ArrayProvider.getObject(); 

    // to access "the other" method
    ArrayProvider provider = new ArrayProvider();
    String[] result2 = provider.getArray();
  }
}

---

Further Reading

• The Java Tutorial (Your question targets basic Java knowledge)

Answer 2

Just import other package and instantiate the class B and call the function.

package Package1;
import Package2;
Class A {
    void callClassBFunction(){
        B b = new B();  //In Package 1 we are instantiating B, however the reference is missing, it should be B b = new B();
        b.callFunction();
}
package Package2;
public class B { //class B should be public
    Object callFunction(){
        //do something and return object
    }
}