안드로이드 ClassCastException 에러

 

 

TelephonyManager 객체를 생성하여 Mcc Mnc 정보를 가져오는 테스트 앱을 실행중 ClassCastException 에러 발생.

 

1. 원인

   - 아래 TelephonyManager 서비스를 생성하기 위해 파라미터로 전달해야 할 이름을 Context.TELECOM_SERVICE 추가 되어 발생되는 문제.

      > TelephonyManager telephonyManager = (TelephonyManager) getSystemService(Context.TELECOM_SERVICE);

 

2. 수정

   - 아래와 같이 TELEPHONY Service로 변경 

      > TelephonyManager telephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);

 

3. 결론

    - Android 서비스 생성시 클래스명을 잘못 전달되어 사용하고자 하는 클래스와 다른 클래스를 리턴되어 발생.

 

package com.json.client.teleonyinfo;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.util.Log;

public class MainActivity extends AppCompatActivity {
    private String LOG_TAG = "MainActivity: ";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        TelephonyManager telephonyManager = (TelephonyManager) getSystemService(Context.TELECOM_SERVICE);

        if (telephonyManager != null) {
            Log.i(LOG_TAG, "onCreate: telephonyManager.getNetworkOperator() = " + telephonyManager.getNetworkOperator());
            Log.i(LOG_TAG, "onCreate: telephonyManager.getSimOperator() = " + telephonyManager.getSimOperator());
        }
    }
}

 

06-04 09:48:31.883 16595-16595/com.json.client.teleonyinfo E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.json.client.teleonyinfo, PID: 16595
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.json.client.teleonyinfo/com.json.client.teleonyinfo.MainActivity}: java.lang.ClassCastException: android.telecom.TelecomManager cannot be cast to android.telephony.TelephonyManager
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
        at android.app.ActivityThread.access$800(ActivityThread.java:151)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5254)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)
     Caused by: java.lang.ClassCastException: android.telecom.TelecomManager cannot be cast to android.telephony.TelephonyManager
        at com.json.client.teleonyinfo.MainActivity.onCreate(MainActivity.java:18)
        at android.app.Activity.performCreate(Activity.java:5990)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
        at android.app.ActivityThread.access$800(ActivityThread.java:151) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:135) 
        at android.app.ActivityThread.main(ActivityThread.java:5254) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:372) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)