Question

处理短信应用，该应用在收到新消息后崩溃。问题似乎在于广播接收器的传入短信，但我无法弄清楚原因。

广播接收器：

public class SMSBroadcastReceiver extends BroadcastReceiver {

     public static final String SMS_BUNDLE = "pdu";

     public void onReceive(Context context, Intent intent) {
         Bundle intentExtras = intent.getExtras();

         if (intentExtras != null) {
             Object[] sms = (Object[]) intentExtras.get(SMS_BUNDLE);
             String smsMessageStr = "";
             for (int i = 0; i < sms.length; ++i) {     //Line 24
                 String format = intentExtras.getString("format");
                 SmsMessage smsMessage = SmsMessage.createFromPdu((byte[]) sms[i], format);

                 String smsBody = smsMessage.getMessageBody().toString();
                 String address = smsMessage.getOriginatingAddress();

                 smsMessageStr += "SMS From: " + address + "\n";
                 smsMessageStr += smsBody + "\n";
             }

             Toast.makeText(context, "Message Received!", Toast.LENGTH_SHORT).show();

             if (MainActivity.active) {
                 MainActivity inst = MainActivity.instance();
                 inst.updateInbox(smsMessageStr);
             } else {
                 Intent i = new Intent(context, MainActivity.class);
                 i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                 context.startActivity(i);

             }
         }
     }
 }

我在第24行标记了调用异常的地方。

错误：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.haltaar.texting, PID: 15909
    java.lang.RuntimeException: Unable to start receiver com.example.haltaar.texting.SMSBroadcastReceiver: java.lang.NullPointerException: Attempt to get length of null array
      at android.app.ActivityThread.handleReceiver(ActivityThread.java:3194)
      at android.app.ActivityThread.-wrap17(Unknown Source:0)
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1672)
      at android.os.Handler.dispatchMessage(Handler.java:106)
      at android.os.Looper.loop(Looper.java:164)
      at android.app.ActivityThread.main(ActivityThread.java:6494)
      at java.lang.reflect.Method.invoke(Native Method)
      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
    Caused by: java.lang.NullPointerException: Attempt to get length of null array
      at com.example.haltaar.texting.SMSBroadcastReceiver.onReceive(SMSBroadcastReceiver.java:24)
      at android.app.ActivityThread.handleReceiver(ActivityThread.java:3187)
      at android.app.ActivityThread.-wrap17(Unknown Source:0) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1672) 
      at android.os.Handler.dispatchMessage(Handler.java:106) 
      at android.os.Looper.loop(Looper.java:164) 
      at android.app.ActivityThread.main(ActivityThread.java:6494) 
      at java.lang.reflect.Method.invoke(Native Method) 
      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

任何人都可以帮忙解释一下吗？正确调用AFAIK所有权限，并检查intentExtras是否为null应该在检查时阻止sms对象为空？或者我错过了什么？

Answer 1

在调用intent.hasExtra(SMS_BUNDLE)之前检查intent.get(SMS_BUNDLE)以防止空指针异常

SMS广播接收器 - 无法启动接收器：java.lang.NullPointerException：尝试获取null数组的长度

1 个答案: