要抓取系统日记,只需运行adb logcat即可,但需要在终端上运行命令才行。由于权限限制,只有系统应用才能读取系统的log,第三方应用只能读到部分log。现在的手机平台都是在拨号界面输入暗码,即可调用app抓取日记(如mtk平台输可调用mtklogger),于是自己写了一个demo(Android7.0 mtk)。
输入字符串启动应用原理
packages/services/Telephony/src/com/android/phone/SpecialCharSequenceMgr.java
static private boolean handleSecretCode(Context context, String input) {
// Secret codes are in the form *#*##*#*
int len = input.length();
if (len > 8 && input.startsWith("*#*#") && input.endsWith("#*#*")) {
Intent intent = new Intent(TelephonyIntents.SECRET_CODE_ACTION,
Uri.parse("android_secret_code://" + input.substring(4, len - 4)));
context.sendBroadcast(intent);
return true;
}
return false;
}
这里发出了广播,我们只需监听该广播即可。
public class BroastcastReceiverService extends Service {
private BroadcastReceiver receiver;
private String SECRET_CODE_ACTION = "android.provider.Telephony.SECRET_CODE";
private String TAG = "logcat";
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onCreate() {
super.onCreate();
Log.e(TAG,"BroastcastReceiverService start");
receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
Log.e(TAG,"onReceive");
if (intent.getAction().equals(SECRET_CODE_ACTION)){
Uri uri = intent.getData();
String host=uri.getHost();
String scheme=uri.getScheme();
Log.e(TAG,host);
Log.e(TAG,scheme);
if(host.equals("888"))
{
Log.e(TAG,"start logcatread app");
Intent intentobj = new Intent(BroastcastReceiverService.this,MainActivity.class);
startActivity(intentobj);
}
}
}
};
IntentFilter filter = new IntentFilter(SECRET_CODE_ACTION);
filter.addDataScheme("android_secret_code");
registerReceiver(receiver, filter);
}
@Override
public void onDestroy() {
}
}
AndroidManifest.xml加上
启动该服务
frameworks/base/services/java/com/android/server/SystemServer.java
startSystemUi方法中加上
Intent intent1 = new Intent();
intent.setComponent(new ComponentName("www.com.logcatreader", "www.com.logcatreader.BroastcastReceiverService"));
context.startServiceAsUser(intent, UserHandle.SYSTEM);
这里会报错ActivityManager: Unable to start service Intent { cmp=www.com.logcatreader/.BroastcastReceiverService } U=0: not found
查到是这里出错
frameworks/base/core/java/android/content/pm/PackageUserState.java
public boolean isMatch(ComponentInfo componentInfo, int flags) {
if (!isInstalled(flags)) return false;
if (!isEnabled(componentInfo, flags)) return false;
if ((flags & MATCH_SYSTEM_ONLY) != 0) {
if (!componentInfo.applicationInfo.isSystemApp()) {
return false;
}
}
final boolean matchesUnaware = ((flags & MATCH_DIRECT_BOOT_UNAWARE) != 0)
&& !componentInfo.directBootAware;
final boolean matchesAware = ((flags & MATCH_DIRECT_BOOT_AWARE) != 0)
&& componentInfo.directBootAware;
Log.v(TAG,matchesUnaware+""+matchesAware);
Log.v(TAG,flags+"");
return matchesUnaware || matchesAware;
}
AndroidManifest.xml加上
android:directBootAware="true"
系统休眠后,该服务就被杀掉到了,在AndroidManifest.xml加上
android:persistent="true"
抓取logcat代码
@Override
public void run() {
try {
File folder = new File("/mnt/sdcard/Android/syslog");
if(!folder.exists())
{
boolean ret=folder.mkdirs();
if(!ret) {
Log.e(TAG, "create folder failed");
return;
}
}
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyyMMdd_HHmmss");// HH:mm:ss
Date date = new Date(System.currentTimeMillis());
String tg = simpleDateFormat.format(date);
Log.e(TAG, tg);
file = new File(folder, tg + ".txt");
String line;
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
return;
}
}
Process process = Runtime.getRuntime().exec("logcat");
out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file, true)));
Log.e(TAG, "Process : " + process);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while ((line = bufferedReader.readLine()) != null) {
out.write(line);
out.write("\r\n");
if(!isObserverLog){
out.close();
Log.e(TAG, "close" );
break;
}
}
} catch (IOException e) {
e.printStackTrace();
};
Log.e(TAG, "thread exit" );
}
再把应用的图标隐藏掉,在AndroidManifest.xml注释
将该应用编译进系统
在AndroidManifest.xml加上
android:sharedUserId="android.uid.system"
这里用android-studio写代码,调试完后,选择Build->Bulid-APK(s),app/build/outputs/apk/debug/app-debug.apk
即我们需要的apk,并将该app改名为logcatreader.apk
编写Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := logcatreader
LOCAL_MODULE_CLASS := APPS
LOCAL_MODULE_TAGS := optional
LOCAL_BUILT_MODULE_STEM := package.apk
LOCAL_MODULE_SUFFIX := $(COMMON_ANDROID_PACKAGE_SUFFIX)
LOCAL_CERTIFICATE := platform
LOCAL_PRIVILEGED_MODULE := true
LOCAL_SRC_FILES := $(LOCAL_MODULE).apk
include $(BUILD_PREBUILT)
mmm进行编译(如果要编译到系统,加入PRODUCT_PACKAGES+=logcatreader),并push到系统。
源码地址 https://github.com/wew888/logcatreader.git