After the Android Application is uninstalled, the specified connection is automatically opened in the browser.

After the Android Application is uninstalled, the specified connection is automatically opened in the browser.

This document describes how to automatically open a specified connection in a browser after an Android Application is uninstalled.
Principle: In the android program somewhere, call C code based on JNI to enable a sub-process to monitor the file directory of the application in the system. Once the application is uninstalled, the directory will be deleted by the system, at this time, the sub-process is triggered to execute the relevant code (this example calls the browser to execute and open a connection)
1. Create a jni directory under the android Project
2. Create the file observer. c In the jni directory.

/** Copyright (C) 2009 The Android Open Source Project ** Licensed under the Apache License, Version 2.0 (the "License "); * you may not use this file before t in compliance with the License. * You may be obtain a copy of the License at ** http://www.apache.org/licenses/LICENSE-2.0 ** Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "as is" BASIS, * without warranties or conditions of any kind, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. **/# include
  
   
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           /* Macro definition begin * // clear 0 macro # define MEM_ZERO (pDest, destSize) memset (pDest, 0, destSize) // LOG macro definition # define LOG_INFO (tag, msg) _ android_log_write (ANDROID_LOG_INFO, tag, msg) # define LOG_DEBUG (tag, msg) _ android_log_write (ANDROID_LOG_DEBUG, tag, msg) # define LOG_WARN (tag, msg) _ android_log_write (ANDROID_LOG_WARN, tag, msg) # define LOG_ERROR (tag, msg) _ android_log_write (ANDROID_LOG_ERROR, tag, msg)/* global variable begin */Static char c_TAG [] = "onEvent"; static jboolean B _IS_COPY = JNI_TRUE;/* expose the natvie Method */jstring encode (JNIEnv * env, jobject thiz, jstring path, jstring url, jint version) {jstring tag = (* env)-> NewStringUTF (env, c_TAG); // initialize log LOG_DEBUG (* env) -> GetStringUTFChars (env, tag, & B _IS_COPY), (* env)-> GetStringUTFChars (env, (* env)-> NewStri NgUTF (env, "init OK"), & B _IS_COPY); // fork sub-process to run the polling task pid_t pid = fork (); if (pid <0) {// Error log LOG_ERROR (* env)-> GetStringUTFChars (env, tag, & B _IS_COPY), (* env)-> GetStringUTFChars (env, (* env) -> NewStringUTF (env, "fork failed !!! "), & B _IS_COPY);} else if (pid = 0) {// subprocess registration directory listener int fileDescriptor = inotify_init (); if (fileDescriptor <0) {LOG_DEBUG (* env)-> GetStringUTFChars (env, tag, & B _IS_COPY), (* env)-> GetStringUTFChars (env, (* env)-> NewStringUTF (env, "inotify_init failed !!! "), & B _IS_COPY); exit (1);} int watchDescriptor; watchDescriptor = inotify_add_watch (fileDescriptor, (* env)-> GetStringUTFChars (env, path, NULL ), IN_DELETE); if (watchDescriptor <0) {LOG_DEBUG (* env)-> GetStringUTFChars (env, tag, & B _IS_COPY), (* env)-> GetStringUTFChars (env, (* env)-> NewStringUTF (env, "inotify_add_watch failed !!! "), & B _IS_COPY); exit (1) ;}// allocate the cache to read the event. The cache size = the size of a struct inotify_event, in this case, an event void * p_buf = malloc (sizeof (struct inotify_event); if (p_buf = NULL) {LOG_DEBUG (* env)-> GetStringUTFChars (env, tag, & B _IS_COPY), (* env)-> GetStringUTFChars (env, (* env)-> NewStringUTF (env, "malloc failed !!! "), & B _IS_COPY); exit (1) ;}// start listening to LOG_DEBUG (* env)-> GetStringUTFChars (env, tag, & B _IS_COPY), (* env) -> GetStringUTFChars (env, (* env)-> NewStringUTF (env, "start observer"), & B _IS_COPY); // read will block the process, size_t readBytes = read (fileDescriptor, p_buf, sizeof (struct inotify_event); // when you go to this page, you will receive the directory deletion event, deregister the listener free (p_buf), inotify_rm_watch, IN_DELETE); // The directory does not contain log LOG_DEBUG (* env)-> GetStringUTFC Hars (env, tag, & B _IS_COPY), (* env)-> GetStringUTFChars (env, (* env)-> NewStringUTF (env, "uninstalled"), & B _IS_COPY )); if (version> = 17) {// because the user permission management is stricter, add -- user 0 execlp ("am", "am", "start ", "-- user", "0", "-a", "android. intent. action. VIEW ","-d ", (* env)-> GetStringUTFChars (env, url, NULL), (char *) NULL);} else {execlp (" am ", "am", "start", "-a", "android. intent. action. VIEW ","-d ", (* env )-> GetStringUTFChars (env, url, NULL), (char *) NULL);} // Extension: other shell commands, am (activity manager ), you can open a program, service, broadcast intent, and so on} else {// The parent process exits directly, so that the child process is adopted by the init process to prevent the child process from freezing} return (* env) -> NewStringUTF (env, "Hello from JNI! ");}
         
        
       
      
     
    
   
  

3. Create the Android. mk file in the jni directory.

LOCAL_PATH := $(call my-dir)include $(CLEAR_VARS)LOCAL_MODULE:=observerLOCAL_SRC_FILES:=observer.cLOCAL_C_INCLUDES:= $(LOCAL_PATH)/includeLOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -lloginclude $(BUILD_SHARED_LIBRARY)

4. Create the natvie method and call the JNI method in Android.

Package com. zgy. catchuninstallself; public class UninstallObserver {static {System. loadLibrary ("observer");} public static native String startWork (String path, String url, int version); // path: data/[packageNmae]; url: the page to jump to. It must start with http: // or https}

String url = "http://www.baidu.com";UninstallObserver.startWork(path, url, android.os.Build.VERSION.SDK_INT);

Note: When the JNI method is repeatedly called, I did not test whether multiple sub-processes will be enabled again. This is left for testing.