Android短信监听功能(解决onChange触发两次的问题)

前言
项目要做短信验证码自动填充的功能，基本上两种方法：ContentObserver监听短信数据库、广播。我个人比较喜欢监听数据库的方式，原因有以下几点：
1.广播方式只能读短信，不能写短信（比如更新短信状态为已读）；而监听数据库则可以对短信做增删改查；
2.系统的短信广播是有序广播，如果有其他应用的优先级高于我们的应用，广播会先被其他应用截获，如果其他应用截获短信广播后将其消费掉并且不再继续发送，那我们的应用就收不到广播了；
3.广播方式需要注册receiver，动态注册还好，如果是静态注册，对于sdk类的产品来说，使用者有可能忘记在Manifest中注册；
基于以上原因，我的项目中索性就选择了监听数据库。监听数据库相对于广播稍微复杂点，但是更加灵活，功能更强大，所以还是建议使用监听数据库的方法，不过这里会将两种都说一下。

方法一：监听短信数据库
遇到的问题是大部分手机收到一条短信时会触发两次onChange()方法，很多人提出的解决方法是记录smsId,判断如果是旧的就不做处理，是新的就做该做的事。起初这么做了，后来发现有时候自动填充会先填旧的，立马又填新的，会闪一下，虽然只是偶尔出现，但还是觉得不爽，于是抽空又找别的方法，总算找出来了，也是受到一些网友的启发，下面就分享出来，原理我不多说了，代码注释里都讲得很清楚。

package com.jackie.bindmobile;

import android.app.Activity;
import android.database.ContentObserver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Handler;
import android.text.TextUtils;
import android.util.Log;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Monitor sms database
 * 
 * @author Jackie
 *
 */
public class SmsContent extends ContentObserver {

	private static final String TAG = SmsContent.class.getSimpleName();
	private static final String MARKER = "YOUR_KEYWORD";
	private Cursor cursor = null;
	private Activity mActivity;

	public SmsContent(Handler handler, Activity activity) {
		super(handler);
		this.mActivity = activity;
	}

	/**
	 * This method is called when a content change occurs.
	 * <p>
	 * Subclasses should override this method to handle content changes.
	 * </p>
	 *
	 * @param selfChange True if this is a self-change notification.
	 */
	@Override
	public void onChange(boolean selfChange) {
		super.onChange(selfChange);
		Log.d(TAG, "onChange(boolean selfChange). selfChange=" + selfChange);
		onChange(selfChange, null);
	}

	/**
	 * Notice: onChange will be triggered twice on some devices when a sms received,
	 * eg: samsung s7 edge(API.23) - twice
	 *     samsung note3(API.18) - once
	 * 06-15 11:45:48.706 D/SmsContent: onChange(boolean selfChange, Uri uri). selfChange=false, uri=content://sms/raw
	 * 06-15 11:45:49.466 D/SmsContent: onChange(boolean selfChange, Uri uri). selfChange=false, uri=content://sms/387
	 *
	 * Generally onChange will be triggered twice, first time is triggered by uri "content://sms/raw"(sms received,
	 * but have not written into inbox), second time is triggered by uri "content://sms/387"(number is sms id)
	 *
	 * Android official comments:
	 * This method is called when a content change occurs.
	 * Includes the changed content Uri when available.
	 * <p>
	 * Subclasses should override this method to handle content changes.
	 * To ensure correct operation on older versions of the framework that
	 * did not provide a Uri argument, applications should also implement
	 * the {@link #onChange(boolean)} overload of this method whenever they
	 * implement the {@link #onChange(boolean, Uri)} overload.
	 * </p><p>
	 * Example implementation:
	 * <pre><code>
	 * // Implement the onChange(boolean) method to delegate the change notification to
	 * // the onChange(boolean, Uri) method to ensure correct operation on older versions
	 * // of the framework that did not have the onChange(boolean, Uri) method.
	 * {@literal @Override}
	 * public void onChange(boolean selfChange) {
	 *     onChange(selfChange, null);
	 * }
	 *
	 * // Implement the onChange(boolean, Uri) method to take advantage of the new Uri argument.
	 * {@literal @Override}
	 * public void onChange(boolean selfChange, Uri uri) {
	 *     // Handle change.
	 * }
	 * </code></pre>
	 * </p>
	 *
	 * @param selfChange True if this is a self-change notification.
	 * @param uri The Uri of the changed content, or null if unknown.
	 */
	@Override
	public void onChange(boolean selfChange, Uri uri) {
		Log.d(TAG, "onChange(boolean selfChange, Uri uri). selfChange=" + selfChange + ", uri=" + uri);

		/**
		 * 适配某些较旧的设备，可能只会触发onChange(boolean selfChange)方法，没有传回uri参数，
		 * 此时只能通过"content://sms/inbox"来查询短信
		 */
		if (uri == null) {
			uri = Uri.parse("content://sms/inbox");
		}
		/**
		 * 06-15 11:45:48.706 D/SmsContent: onChange(boolean selfChange, Uri uri). selfChange=false, uri=content://sms/raw
		 * 06-15 11:45:49.466 D/SmsContent: onChange(boolean selfChange, Uri uri). selfChange=false, uri=content://sms/387
		 *
		 * Generally onChange will be triggered twice, first time is triggered by uri "content://sms/raw"(sms received,
		 * but have not written into inbox), second time is triggered by uri "content://sms/387"(number is sms id)
 		 */
		if (uri.toString().equals("content://sms/raw")) {
			return;
		}
		cursor = this.mActivity.getContentResolver().query(uri, null, null, null, null);
		if (cursor != null) {
			if (cursor.moveToFirst()) {
				int id = cursor.getInt(cursor.getColumnIndex("_id"));
				String body = cursor.getString(cursor.getColumnIndex("body"));
				Log.d(TAG, "sms id: " + id + "\nsms body: " + body);
				cursor.close();

				// Already got sms body, do anything you want, for example: filter the verify code
				getVerifyCode(body);
			}
		}
		else {
			Log.e(TAG, "error: cursor == null");
		}
	}
	
	/**
	 * Register a monitor of changing of sms
	 */
	public void register() {
		Log.d(TAG, "Register sms monitor");
		this.mActivity.getContentResolver().registerContentObserver(
				Uri.parse("content://sms/"), true, this);
	}
	
	/**
	 * Unregister the monitor of changing of sms
	 */
	public void unRegister() {
		Log.d(TAG, "Unregister sms monitor");
		this.mActivity.getContentResolver().unregisterContentObserver(this);
	}

	/**
	 * Get verify code from sms body
	 * @param str
	 * @return
     */
	public String getVerifyCode(String str) {
		String verifyCode = null;
		if (smsContentFilter(str)) {
			Log.d(TAG, "sms content matched, auto-fill verify code.");
			verifyCode = getDynamicPassword(str);
		}
		else {
			// Do nothing
			Log.d(TAG, "sms content did not match, do nothing.");
		}
		return verifyCode;
	}

	/**
	 * Check if str is verification-code-formatted
	 *
	 * @param str
	 * @return
     */
	private boolean smsContentFilter(String str) {
		Log.d(TAG, "smsContentFilter. smsBody = " + str);
		boolean isMatched = false;
		if (!TextUtils.isEmpty(str)) {
			// Check if str contains keyword
			if (str.contains(MARKER)) {
				Log.d(TAG, "This sms contains \"" + MARKER + "\"");
				// Check if str contains continuous 6 numbers
				Pattern  continuousNumberPattern = Pattern.compile("[0-9\\.]+");
				Matcher m = continuousNumberPattern.matcher(str);
				while(m.find()){
					if(m.group().length() == 6) {
						Log.d(TAG, "This sms contains continuous 6 numbers : " + m.group());
						isMatched = true;
					}
				}
			}
		}
		return isMatched;
	}

	/**
     * Cut the continuous 6 numbers from str
     * 
     * @param str sms content
     * @return verification code
     */
    private String getDynamicPassword(String str) {
    	Log.d(TAG, "getDynamicPassword. smsBody = " + str);
        Pattern  continuousNumberPattern = Pattern.compile("[0-9\\.]+");
        Matcher m = continuousNumberPattern.matcher(str);
        String dynamicPassword = "";
        while(m.find()){
            if(m.group().length() == 6) {
            	Log.d(TAG, m.group());
                dynamicPassword = m.group();
            }
        }

        Log.d(TAG, "Verification code: " + dynamicPassword);
        return dynamicPassword;
    }
}

用法很简单，注册和注销一下就行：

package com.jackie.bindmobile;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;

public class BindMobileActivity extends Activity {

    private static final String TAG = BindMobileActivity.class.getSimpleName();
    private SmsContent smsContent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Register sms monitor
        smsContent = new SmsContent(new Handler(), mActivity);
        smsContent.register();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // Unregister sms monitor
        smsContent.unRegister();
    }
}

方法二：广播

public class SMSBroadcastReceiver extends BroadcastReceiver {

    private static final String TAG = "SMSBroadcastReceiver";

    private SMSBroadcastReceiver() {
    }

    public static SMSBroadcastReceiver buildSMSReceiver(Context context) {
        SMSBroadcastReceiver smsReceiver = new SMSBroadcastReceiver();
        IntentFilter iff = new IntentFilter("android.provider.Telephony.SMS_RECEIVED");
        iff.setPriority(IntentFilter.SYSTEM_HIGH_PRIORITY);
        context.registerReceiver(smsReceiver, iff);
        return smsReceiver;
    }

    public static void unregisterSMSReceiver(Context context, SMSBroadcastReceiver receiver) {
        context.unregisterReceiver(receiver);
    }

    @SuppressLint("SimpleDateFormat")
    @Override
    public void onReceive(Context context, Intent intent) {
        Object[] pdus = (Object[]) intent.getExtras().get("pdus");
        for (Object pdu : pdus) {
            SmsMessage smsMessage = SmsMessage.createFromPdu((byte[]) pdu);
            String sender = smsMessage.getDisplayOriginatingAddress();
            String content = smsMessage.getMessageBody();
            long date = smsMessage.getTimestampMillis();
            Date timeDate = new Date(date);
            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            String time = simpleDateFormat.format(timeDate);
            Log.i(TAG, " ------------- Incoming message details start ------------- ");
            Log.i(TAG, "SMS from: " + sender);
            Log.i(TAG, "SMS body: " + content);
            Log.i(TAG, "SMS timestamp: " + time);
            LogCat.i(TAG, " ------------- Incoming message details end ------------- ");
            // Mark SMS as read
            markAsRead(context, sender);
        }
    }

    private void markAsRead(final Context context, final String sender) {
        // Can not get the latest sms from ContentResolver on Android4.3 device if not run in sub thread
        new Thread(new Runnable() {
            @Override
            public void run() {
                // Wait for mobile system to write sms into database
                try {
                    Thread.sleep(3000);
                } catch (InterruptedException e) {
                    Log.e(TAG, e.getMessage());
                }
                // Query sms from database
                Uri uri = Uri.parse("content://sms/inbox");
                String where = " address = " + sender;
                ContentResolver resolver = context.getContentResolver();
                Cursor cursor = resolver.query(uri, null, where, null, "_id desc");
                if (null == cursor) return;
                if (cursor.moveToNext()) {
                    // Query status
                    String smsId = cursor.getString(cursor.getColumnIndex("_id"));
                    int read = cursor.getInt(cursor.getColumnIndex("read"));
                    String smsBody = cursor.getString(cursor.getColumnIndex("body"));
                    Log.d(TAG, "Before update. smsId=" + smsId + ", read=" + read + ", smsBody=" + smsBody);
                    // Mark as read
                    ContentValues values = new ContentValues();
                    values.put("read", 1);
                    resolver.update(uri, values, "_id=" + smsId, null);
                    Log.d(TAG, "Mark as read DONE");
                    // Confirm status
                    cursor = resolver.query(uri, null, "_id=" + smsId, null, null);
                    cursor.moveToNext();
                    smsId = cursor.getString(cursor.getColumnIndex("_id"));
                    read = cursor.getInt(cursor.getColumnIndex("read"));
                    smsBody = cursor.getString(cursor.getColumnIndex("body"));
                    Log.d(TAG, "After update. smsId=" + smsId + ", read=" + read + ", smsBody=" + smsBody);
                }
                cursor.close();
            }
        }).start();
    }
}

用法也很简单，比如你要在一个Service中使用，只要注册和注销即可：

class SMSService extends Service{
	
	private SMSBroadcastReceiver smsBroadcastReceiver;

	@Override
	private void onCreate() {
		smsBroadcastReceiver = SMSBroadcastReceiver.buildSMSReceiver(this);
	}

	@Override
    public void onDestroy() {
        SMSBroadcastReceiver.unregisterSMSReceiver(this, smsBroadcastReceiver);
        super.onDestroy();
    }
}

上面的例子实现的功能是接收短信广播，收到后将短信设置为已读，实现过程是当触发onReceive后，通过ContentResolver读取短信数据库，并更新相应短信的状态为已读。需要注意里面两个地方：
1.为什么要做3秒的延迟，再去读取短信数据库：
是为了等待手机系统将短信写入短信数据库中，否则你读到的就是旧的数据库信息，不包含刚收到的短信。关于这一点，我的理解是：广播机制它是系统一旦收到短信，就发出一个广播，并将短信内容以pdus的形式放在Intent中，同时系统又去将短信往数据库中写入，发广播和写数据库是并行进行的，他们之间没有什么先后关系，所以当我们收到onReceive时其实很可能短信还没被写入数据库，如果此时去读取数据库，就读不到最新的这条短信。当然我没有去证实这个观点，但应该是八九不离十。
2.更新短信状态的处理为什么要放在子线程：
这个就只是为了适配老设备，起初没有放在子线程中，我在红米（Android4.4.4）上测试时没有问题，只要延时3秒就能读到最新的短消息，但是在一台很老的联想机（Android4.3）上面就总是读到的之前一条短信内容，即便我将延时设置为30秒也没用，我不确定是设备太老还是系统版本太旧，但我偶然发现将这个处理放在子线程后3秒就可以读到最新的短信。如果有大神能解释一下，请多多指教。

其实，方法二这样的功能，最好还是使用第一种方式监听短信，因为只有第一种方式能够写短信内容，而广播只能读短信，如果硬要将两种方式结合起来用，那在读取短信数据库前就不得不做一定的延时处理了。