我正在尝试使用上下文传输将上下文导入此 android 文件。但是，如果我的消息包含“aakash”，则此代码会意外终止，并给出代码后显示的错误。
我该怎么办 ？
public class messagebody extends BroadcastReceiver{
Context mContext;
public messagebody(Context context){
this.mContext = context;
Log.i(TAG, "yayyyy: " );
}
public messagebody(){
}
private static final String SMS_RECEIVED = "android.provider.Telephony.SMS_RECEIVED";
private static final String TAG = "SMSBroadcastReceiver";
@Override
public void onReceive(Context context, Intent intent) {
Log.i(TAG, "Intent recieved: " + intent.getAction());
if (intent.getAction().equals(SMS_RECEIVED)) {
Bundle bundle = intent.getExtras();
if (bundle != null) {
Object[] pdus = (Object[])bundle.get("pdus");
final SmsMessage[] messages = new SmsMessage[pdus.length];
for (int i = 0; i < pdus.length; i++) {
messages[i] = SmsMessage.createFromPdu((byte[])pdus[i]);
}
if (messages.length > -1) {
// Toast.makeText(context, "Message recieved: " + messages[0].getMessageBody(), 7000).show();
if(messages[0].getMessageBody().contains("aakash"))
{
/*AudioManager am = (AudioManager)mContext.getSystemService(Context.AUDIO_SERVICE);
switch (am.getRingerMode()) {
case AudioManager.RINGER_MODE_NORMAL:
//Log.i("MyApp","NORMAL mode");
am.setRingerMode(AudioManager.RINGER_MODE_VIBRATE);
Toast toast2=Toast.makeText(mContext, "Vibrate", Toast.LENGTH_LONG);
toast2.show();
break;
case AudioManager.RINGER_MODE_VIBRATE:
//Log.i("MyApp","VIBRATE mode");
am.setRingerMode(AudioManager.RINGER_MODE_NORMAL);
Toast toast1=Toast.makeText(mContext, "Normal", Toast.LENGTH_LONG);
toast1.show();
break; */
Toast toast1=Toast.makeText(mContext, "Normal", Toast.LENGTH_LONG);
toast1.show();
}
}
}
}
}
}
错误如下：
11-26 15:03:43.150: E/AndroidRuntime(2056): FATAL EXCEPTION: main
11-26 15:03:43.150: E/AndroidRuntime(2056): java.lang.RuntimeException: Unable to start receiver com.example.messages.messagebody: java.lang.NullPointerException
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2236)
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.app.ActivityThread.access$1500(ActivityThread.java:130)
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1271)
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.os.Handler.dispatchMessage(Handler.java:99)
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.os.Looper.loop(Looper.java:137)
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.app.ActivityThread.main(ActivityThread.java:4745)
11-26 15:03:43.150: E/AndroidRuntime(2056): at java.lang.reflect.Method.invokeNative(Native Method)
11-26 15:03:43.150: E/AndroidRuntime(2056): at java.lang.reflect.Method.invoke(Method.java:511)
11-26 15:03:43.150: E/AndroidRuntime(2056): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
11-26 15:03:43.150: E/AndroidRuntime(2056): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
11-26 15:03:43.150: E/AndroidRuntime(2056): at dalvik.system.NativeStart.main(Native Method)
11-26 15:03:43.150: E/AndroidRuntime(2056): Caused by: java.lang.NullPointerException
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.widget.Toast.<init>(Toast.java:92)
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.widget.Toast.makeText(Toast.java:238)
11-26 15:03:43.150: E/AndroidRuntime(2056): at com.example.messages.messagebody.onReceive(messagebody.java:68)
11-26 15:03:43.150: E/AndroidRuntime(2056): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2229)
将 mContext 更改为上下文后，新代码出现空指针异常。代码是
package com.example.messages;
import com.example.messages.R;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.media.AudioManager;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.util.Log;
import android.widget.Toast;
import android.media.AudioManager;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class messagebody extends BroadcastReceiver{
Context mContext;
public messagebody(Context context){
this.mContext = context;
Log.i(TAG, "yayyyy: " );
}
public messagebody(){
}
private static final String SMS_RECEIVED = "android.provider.Telephony.SMS_RECEIVED";
private static final String TAG = "SMSBroadcastReceiver";
@Override
public void onReceive(Context context, Intent intent) {
Log.i(TAG, "Intent recieved: " + intent.getAction());
if (intent.getAction().equals(SMS_RECEIVED)) {
Bundle bundle = intent.getExtras();
if (bundle != null) {
Object[] pdus = (Object[])bundle.get("pdus");
final SmsMessage[] messages = new SmsMessage[pdus.length];
for (int i = 0; i < pdus.length; i++) {
messages[i] = SmsMessage.createFromPdu((byte[])pdus[i]);
}
if (messages.length > -1) {
// Toast.makeText(context, "Message recieved: " + messages[0].getMessageBody(), 7000).show();
if(messages[0].getMessageBody().contains("aakash"))
{
Toast toast3=Toast.makeText(context, "Normal", Toast.LENGTH_LONG);
toast3.show();
AudioManager am = (AudioManager)mContext.getSystemService(Context.AUDIO_SERVICE);
switch (am.getRingerMode()) {
case AudioManager.RINGER_MODE_NORMAL:
//Log.i("MyApp","NORMAL mode");
am.setRingerMode(AudioManager.RINGER_MODE_VIBRATE);
Toast toast2=Toast.makeText(context, "Vibrate", Toast.LENGTH_LONG);
toast2.show();
break;
case AudioManager.RINGER_MODE_VIBRATE:
//Log.i("MyApp","VIBRATE mode");
am.setRingerMode(AudioManager.RINGER_MODE_NORMAL);
Toast toast1=Toast.makeText(context, "Normal", Toast.LENGTH_LONG);
toast1.show();
break;
}
}
}
}
}
}
}