Android应用如何监听自己是否被卸载及卸载反馈功能的实现

　　一个应用被用户卸载肯定是有理由的，而开发者却未必能得知这一重要的理由，毕竟用户很少会主动反馈建议，多半就是用得不爽就卸，如果能在被卸载后获取到用户的一些反馈，那对开发者进一步改进应用是非常有利的。目前据我所知，国内的Android应用中实现这一功能的只有360手机卫士、360平板卫士，那么如何实现这一功能的？

　　我们可以把实现卸载反馈的问题转化为监听自己是否被卸载，只有得知自己被卸载，才可以设计相应的反馈处理流程。以下的列表是我在研究这一问题的思路：

　　1，注册BroadcastReceiver，监听"android.intent.action.PACKAGE_REMOVED"系统广播

　　结果：NO。未写代码，直接分析，卸载的第一步就是退出当前应用的主进程，而此广播是在已经卸载完成后才发出的，此时主进程都没有了，去哪onReceive()呢？

　　2，若能收到"将要卸载XX包"的系统广播，在主进程被退出之前就抢先进行反馈处理就好了，可惜没有这样的系统广播，不过经过调研，倒是发现了一个办法，读取系统log，当日志中包含"android.intent.action.DELETE"和自己的包名时，意味着自己将要被卸载。

　　结果：NO。调试时发现此方法有两个缺陷，（1）点击设置中的卸载按钮即发出此Intent，此时用户尚未在弹框中确认卸载；（2）pm命令卸载不出发此Intent，意味着被诸如手机安全管家，豌豆荚等软件卸载时，无法提前得知卸载意图。

　　3，由于时间点不容易把控，所以干脆不依赖系统广播或log，考虑到卸载过程会删除"/data/data/包名"目录，我们可以用线程直接轮询这个目录是否存在，以此为依据判断自己是否被卸载。

　　结果：NO。同方法1，主进程退出，相应的线程必定退出，线程还没等到判断目录是否存在就已经被销毁了。

　　4，改用C端进程轮询"/data/data/包名"目录是否存在

　　结果：YES。借助Java端进程fork出来的C端进程在应用被卸载后不会被销毁。

　　OK，上代码！

Activity启动时fork出C端进程轮询目录：

package main.activity; 2  3 import pym.test.uninstalledmoniter.R; 4 import android.app.Activity; 5 import android.os.Bundle; 6 import android.util.Log; 7  8 /** 9  * @author pengyiming10  * @note 监听此应用是否被卸载，若被卸载则弹出卸载反馈11  *12  */13 14 public class UninstalledMoniterActivity extends Activity15 {16     /* 数据段begin */17     private static final String TAG = "UninstalledMoniterActivity";18     /* 数据段end */19     20     /* 函数段begin */21     private native void init();22     static23     {24         Log.d(TAG, "load libuninstalled_moniter");25         System.loadLibrary("uninstalled_moniter");26     }27     28     @Override29     public void onCreate(Bundle savedInstanceState)30     {31         super.onCreate(savedInstanceState);32         Log.d(TAG, "onCreate");33         34         setContentView(R.layout.uninstalled_moniter_layout);35         36         init();37     }38     /* 函数段end */39 }

核心——native方法头文件：

/* 头文件begin */ 2 #include <jni.h> 3 #include <stdio.h> 4 #include <string.h> 5 #include <android/log.h> 6 #include <unistd.h> 7 /* 头文件end */ 8  9 /* 宏定义begin */10 //清0宏11 #define MEM_ZERO(pDest, destSize) memset(pDest, 0, destSize)12 13 //LOG宏定义14 #define LOG_INFO(tag, msg) __android_log_write(ANDROID_LOG_INFO, tag, msg)15 #define LOG_DEBUG(tag, msg) __android_log_write(ANDROID_LOG_DEBUG, tag, msg)16 #define LOG_WARN(tag, msg) __android_log_write(ANDROID_LOG_WARN, tag, msg)17 #define LOG_ERROR(tag, msg) __android_log_write(ANDROID_LOG_ERROR, tag, msg)18 /* 宏定义end */19 20 #ifndef _Included_main_activity_UninstalledMoniterActivity21 #define _Included_main_activity_UninstalledMoniterActivity22 #ifdef __cplusplus23 extern "C" {24 #endif25 26 #undef main_activity_UninstalledMoniterActivity_MODE_PRIVATE27 #define main_activity_UninstalledMoniterActivity_MODE_PRIVATE 0L28 #undef main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE29 #define main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE 1L30 #undef main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE31 #define main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE 2L32 #undef main_activity_UninstalledMoniterActivity_MODE_APPEND33 #define main_activity_UninstalledMoniterActivity_MODE_APPEND 32768L34 #undef main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS35 #define main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS 4L36 #undef main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE37 #define main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE 1L38 #undef main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND39 #define main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND 2L40 #undef main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND41 #define main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND 4L42 #undef main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT43 #define main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT 8L44 #undef main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT45 #define main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT 16L46 #undef main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY47 #define main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY 32L48 #undef main_activity_UninstalledMoniterActivity_BIND_IMPORTANT49 #define main_activity_UninstalledMoniterActivity_BIND_IMPORTANT 64L50 #undef main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY51 #define main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY 128L52 #undef main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE53 #define main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE 1L54 #undef main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY55 #define main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY 2L56 #undef main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED57 #define main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED 4L58 #undef main_activity_UninstalledMoniterActivity_RESULT_CANCELED59 #define main_activity_UninstalledMoniterActivity_RESULT_CANCELED 0L60 #undef main_activity_UninstalledMoniterActivity_RESULT_OK61 #define main_activity_UninstalledMoniterActivity_RESULT_OK -1L62 #undef main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER63 #define main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER 1L64 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE65 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE 0L66 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER67 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER 1L68 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT69 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT 2L70 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL71 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L72 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL73 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L74 75 /*76  * Class:     main_activity_UninstalledMoniterActivity77  * Method:    init78  * Signature: ()V79  */80 JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *, jobject);81 82 #ifdef __cplusplus83 }84 #endif85 #endif

核心——native方法实现：

/* 头文件begin */ 2 #include "main_activity_UninstalledMoniterActivity.h" 3 /* 头文件end */ 4  5 #ifdef __cplusplus 6 extern "C" { 7 #endif 8  9 /* 内全局变量begin */10 static char c_TAG[] = "UninstalledMoniterActivity.init";11 static jboolean b_IS_COPY = JNI_TRUE;12 /* 内全局变量 */13 14 /*15  * Class:     main_activity_UninstalledMoniterActivity16  * Method:    init17  * Signature: ()V18  */19 JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *env, jobject obj)20 {21     jstring tag = (*env)->NewStringUTF(env, c_TAG);22 23     //初始化log24     LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)25             , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "init OK"), &b_IS_COPY));26 27     //fork子进程，以执行轮询任务28     pid_t pid = fork();29     if (pid < 0)30     {31         //出错log32         LOG_ERROR((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)33                 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "fork error !!!"), &b_IS_COPY));34     }35     else if (pid == 0)36     {37         //子进程轮询"/data/data/pym.test.uninstalledmoniter"目录是否存在，若不存在则说明已被卸载38         while (1)39         {40             FILE *p_file = fopen("/data/data/pym.test.uninstalledmoniter", "r");41             if (p_file != NULL)42             {43                 fclose(p_file);44 45                 //目录存在log46                 LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)47                             , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "I'm OK !!!"), &b_IS_COPY));48 49                 sleep(1);50             }51             else52             {53                 //目录不存在log54                 LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)55                             , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "I'm NOT OK !!!"), &b_IS_COPY));56 57                 //执行命令am start -a android.intent.action.VIEW -d http://shouji.360.cn/web/uninstall/uninstall.html58                 execlp("am", "am", "start", "-a", "android.intent.action.VIEW", "-d", "http://shouji.360.cn/web/uninstall/uninstall.html", (char *)NULL);59             }60         }61     }62     else63     {64         //父进程直接退出，使子进程被init进程领养，以避免子进程僵死65     }66 }67 68 #ifdef __cplusplus69 }70 #endif

注1：为了调试方便，包含<android/log.h>，使得so在执行过程中也可以像Java端一样方便得打出log。相应的mk文件需要加上以下两句声明

LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -llog

注2：代码中引用了360手机卫士的反馈地址，仅供大家学习、测试使用~~~

2、Android应用如何监听自己是否被卸载及卸载反馈功能的实现（第二版）

昨天发了一篇有关监听自己是否被卸载和卸载反馈功能实现的博客，地址如下：http://www.cnblogs.com/zealotrouge/p/3157126.html，发出去后收到几位热心网友的建议，在此特别感谢@cccode @泡泡糖 @Alexia(minmin) @0x00.pl ，你们的建议就是我前进的动力。

　　昨天的技术方案有一个硬伤，就是每1s就需要轮询目录是否存在，对资源消耗较大，第二版将会解决这一问题。思路是今天想到了一个Android自API1就有的一个类FileObserver，这个类用于监听某个文件的变化状态，如果是目录，这个类还可以监听其子目录及子目录文件的变化状态，通过阅读FileObserver源码，发现其实现利用了Linux内核中一个重要的机制inotify，它是一个内核用于通知用户空间程序文件系统变化的机制，详情可参考http://en.wikipedia.org/wiki/Inotify，里面对inotify有比较详细的说明。

　　使用inotify的好处就在于不需要每1s的轮询，这样就不会无谓地消耗系统资源，使用inotify时会用read()方法阻塞进程，直到收到IN_DELETE通知，此时进程重新被唤醒，执行反馈处理流程。

　　由于Activity代码和Android.mk文件和第一版并无实质性区别，这里就不贴代码了，直接贴出C端进程的实现代码吧。

核心——native方法头文件：

 

/* 头文件begin */ 2 #include <jni.h> 3 #include <stdlib.h> 4 #include <stdio.h> 5 #include <string.h> 6 #include <android/log.h> 7 #include <unistd.h> 8 #include <sys/inotify.h> 9 #include <fcntl.h>10 /* 头文件end */11 12 /* 宏定义begin */13 //清0宏14 #define MEM_ZERO(pDest, destSize) memset(pDest, 0, destSize)15 16 //LOG宏定义17 #define LOG_INFO(tag, msg) __android_log_write(ANDROID_LOG_INFO, tag, msg)18 #define LOG_DEBUG(tag, msg) __android_log_write(ANDROID_LOG_DEBUG, tag, msg)19 #define LOG_WARN(tag, msg) __android_log_write(ANDROID_LOG_WARN, tag, msg)20 #define LOG_ERROR(tag, msg) __android_log_write(ANDROID_LOG_ERROR, tag, msg)21 /* 宏定义end */22 23 #ifndef _Included_main_activity_UninstalledObserverActivity24 #define _Included_main_activity_UninstalledObserverActivity25 #ifdef __cplusplus26 extern "C" {27 #endif28 29 #undef main_activity_UninstalledObserverActivity_MODE_PRIVATE30 #define main_activity_UninstalledObserverActivity_MODE_PRIVATE 0L31 #undef main_activity_UninstalledObserverActivity_MODE_WORLD_READABLE32 #define main_activity_UninstalledObserverActivity_MODE_WORLD_READABLE 1L33 #undef main_activity_UninstalledObserverActivity_MODE_WORLD_WRITEABLE34 #define main_activity_UninstalledObserverActivity_MODE_WORLD_WRITEABLE 2L35 #undef main_activity_UninstalledObserverActivity_MODE_APPEND36 #define main_activity_UninstalledObserverActivity_MODE_APPEND 32768L37 #undef main_activity_UninstalledObserverActivity_MODE_MULTI_PROCESS38 #define main_activity_UninstalledObserverActivity_MODE_MULTI_PROCESS 4L39 #undef main_activity_UninstalledObserverActivity_BIND_AUTO_CREATE40 #define main_activity_UninstalledObserverActivity_BIND_AUTO_CREATE 1L41 #undef main_activity_UninstalledObserverActivity_BIND_DEBUG_UNBIND42 #define main_activity_UninstalledObserverActivity_BIND_DEBUG_UNBIND 2L43 #undef main_activity_UninstalledObserverActivity_BIND_NOT_FOREGROUND44 #define main_activity_UninstalledObserverActivity_BIND_NOT_FOREGROUND 4L45 #undef main_activity_UninstalledObserverActivity_BIND_ABOVE_CLIENT46 #define main_activity_UninstalledObserverActivity_BIND_ABOVE_CLIENT 8L47 #undef main_activity_UninstalledObserverActivity_BIND_ALLOW_OOM_MANAGEMENT48 #define main_activity_UninstalledObserverActivity_BIND_ALLOW_OOM_MANAGEMENT 16L49 #undef main_activity_UninstalledObserverActivity_BIND_WAIVE_PRIORITY50 #define main_activity_UninstalledObserverActivity_BIND_WAIVE_PRIORITY 32L51 #undef main_activity_UninstalledObserverActivity_BIND_IMPORTANT52 #define main_activity_UninstalledObserverActivity_BIND_IMPORTANT 64L53 #undef main_activity_UninstalledObserverActivity_BIND_ADJUST_WITH_ACTIVITY54 #define main_activity_UninstalledObserverActivity_BIND_ADJUST_WITH_ACTIVITY 128L55 #undef main_activity_UninstalledObserverActivity_CONTEXT_INCLUDE_CODE56 #define main_activity_UninstalledObserverActivity_CONTEXT_INCLUDE_CODE 1L57 #undef main_activity_UninstalledObserverActivity_CONTEXT_IGNORE_SECURITY58 #define main_activity_UninstalledObserverActivity_CONTEXT_IGNORE_SECURITY 2L59 #undef main_activity_UninstalledObserverActivity_CONTEXT_RESTRICTED60 #define main_activity_UninstalledObserverActivity_CONTEXT_RESTRICTED 4L61 #undef main_activity_UninstalledObserverActivity_RESULT_CANCELED62 #define main_activity_UninstalledObserverActivity_RESULT_CANCELED 0L63 #undef main_activity_UninstalledObserverActivity_RESULT_OK64 #define main_activity_UninstalledObserverActivity_RESULT_OK -1L65 #undef main_activity_UninstalledObserverActivity_RESULT_FIRST_USER66 #define main_activity_UninstalledObserverActivity_RESULT_FIRST_USER 1L67 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DISABLE68 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DISABLE 0L69 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DIALER70 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DIALER 1L71 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SHORTCUT72 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SHORTCUT 2L73 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_LOCAL74 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L75 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_GLOBAL76 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L77 78 /*79  * Class:     main_activity_UninstalledObserverActivity80  * Method:    init81  * Signature: ()V82  */83 JNIEXPORT void JNICALL Java_main_activity_UninstalledObserverActivity_init(JNIEnv *, jobject);84 85 #ifdef __cplusplus86 }87 #endif88 #endif

 

核心——native方法实现：

 

/* 头文件begin */ 2 #include "main_activity_UninstalledObserverActivity.h" 3 /* 头文件end */ 4  5 #ifdef __cplusplus 6 extern "C" { 7 #endif 8  9 /* 内全局变量begin */10 static char c_TAG[] = "UninstalledObserverActivity.init";11 static jboolean b_IS_COPY = JNI_TRUE;12 /* 内全局变量 */13 14 /*15  * Class:     main_activity_UninstalledObserverActivity16  * Method:    init17  * Signature: ()V18  */19 JNIEXPORT void JNICALL Java_main_activity_UninstalledObserverActivity_init(JNIEnv *env, jobject obj)20 {21     jstring tag = (*env)->NewStringUTF(env, c_TAG);22 23     //初始化log24     LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)25             , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "init OK"), &b_IS_COPY));26 27     //fork子进程，以执行轮询任务28     pid_t pid = fork();29     if (pid < 0)30     {31         //出错log32         LOG_ERROR((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)33                 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "fork failed !!!"), &b_IS_COPY));34     }35     else if (pid == 0)36     {37         //子进程注册"/data/data/pym.test.uninstalledobserver"目录监听器38         int fileDescriptor = inotify_init();39         if (fileDescriptor < 0)40         {41             LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)42                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "inotify_init failed !!!"), &b_IS_COPY));43 44              exit(1);45         }46 47         int watchDescriptor;48         watchDescriptor = inotify_add_watch(fileDescriptor, "/data/data/pym.test.uninstalledobserver", IN_DELETE);49         if (watchDescriptor < 0)50         {51             LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)52                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "inotify_add_watch failed !!!"), &b_IS_COPY));53 54             exit(1);55         }56 57         //分配缓存，以便读取event，缓存大小=一个struct inotify_event的大小，这样一次处理一个event58         void *p_buf = malloc(sizeof(struct inotify_event));59         if (p_buf == NULL)60         {61             LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)62                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "malloc failed !!!"), &b_IS_COPY));63 64             exit(1);65         }66         //开始监听67         LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)68                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "start observer"), &b_IS_COPY));69         size_t readBytes = read(fileDescriptor, p_buf, sizeof(struct inotify_event));70 71         //read会阻塞进程，走到这里说明收到目录被删除的事件，注销监听器72         free(p_buf);73         inotify_rm_watch(fileDescriptor, IN_DELETE);74 75         //目录不存在log76         LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)77                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "uninstalled"), &b_IS_COPY));78 79         //执行命令am start -a android.intent.action.VIEW -d http://shouji.360.cn/web/uninstall/uninstall.html80         execlp("am", "am", "start", "-a", "android.intent.action.VIEW", "-d", "http://shouji.360.cn/web/uninstall/uninstall.html", (char *)NULL);81     }82     else83     {84         //父进程直接退出，使子进程被init进程领养，以避免子进程僵死85     }86 }87 88 #ifdef __cplusplus89 }90 #endif

 

昨天发了一篇有关监听自己是否被卸载和卸载反馈功能实现的博客，地址如下：http://www.cnblogs.com/zealotrouge/p/3157126.html，发出去后收到几位热心网友的建议，在此特别感谢@cccode @泡泡糖 @Alexia(minmin) @0x00.pl ，你们的建议就是我前进的动力。

　　昨天的技术方案有一个硬伤，就是每1s就需要轮询目录是否存在，对资源消耗较大，第二版将会解决这一问题。思路是今天想到了一个Android自API1就有的一个类FileObserver，这个类用于监听某个文件的变化状态，如果是目录，这个类还可以监听其子目录及子目录文件的变化状态，通过阅读FileObserver源码，发现其实现利用了Linux内核中一个重要的机制inotify，它是一个内核用于通知用户空间程序文件系统变化的机制，详情可参考http://en.wikipedia.org/wiki/Inotify，里面对inotify有比较详细的说明。

　　使用inotify的好处就在于不需要每1s的轮询，这样就不会无谓地消耗系统资源，使用inotify时会用read()方法阻塞进程，直到收到IN_DELETE通知，此时进程重新被唤醒，执行反馈处理流程。

　　由于Activity代码和Android.mk文件和第一版并无实质性区别，这里就不贴代码了，直接贴出C端进程的实现代码吧。

核心——native方法头文件：

 

/* 头文件begin */ 2 #include <jni.h> 3 #include <stdlib.h> 4 #include <stdio.h> 5 #include <string.h> 6 #include <android/log.h> 7 #include <unistd.h> 8 #include <sys/inotify.h> 9 #include <fcntl.h>10 /* 头文件end */11 12 /* 宏定义begin */13 //清0宏14 #define MEM_ZERO(pDest, destSize) memset(pDest, 0, destSize)15 16 //LOG宏定义17 #define LOG_INFO(tag, msg) __android_log_write(ANDROID_LOG_INFO, tag, msg)18 #define LOG_DEBUG(tag, msg) __android_log_write(ANDROID_LOG_DEBUG, tag, msg)19 #define LOG_WARN(tag, msg) __android_log_write(ANDROID_LOG_WARN, tag, msg)20 #define LOG_ERROR(tag, msg) __android_log_write(ANDROID_LOG_ERROR, tag, msg)21 /* 宏定义end */22 23 #ifndef _Included_main_activity_UninstalledObserverActivity24 #define _Included_main_activity_UninstalledObserverActivity25 #ifdef __cplusplus26 extern "C" {27 #endif28 29 #undef main_activity_UninstalledObserverActivity_MODE_PRIVATE30 #define main_activity_UninstalledObserverActivity_MODE_PRIVATE 0L31 #undef main_activity_UninstalledObserverActivity_MODE_WORLD_READABLE32 #define main_activity_UninstalledObserverActivity_MODE_WORLD_READABLE 1L33 #undef main_activity_UninstalledObserverActivity_MODE_WORLD_WRITEABLE34 #define main_activity_UninstalledObserverActivity_MODE_WORLD_WRITEABLE 2L35 #undef main_activity_UninstalledObserverActivity_MODE_APPEND36 #define main_activity_UninstalledObserverActivity_MODE_APPEND 32768L37 #undef main_activity_UninstalledObserverActivity_MODE_MULTI_PROCESS38 #define main_activity_UninstalledObserverActivity_MODE_MULTI_PROCESS 4L39 #undef main_activity_UninstalledObserverActivity_BIND_AUTO_CREATE40 #define main_activity_UninstalledObserverActivity_BIND_AUTO_CREATE 1L41 #undef main_activity_UninstalledObserverActivity_BIND_DEBUG_UNBIND42 #define main_activity_UninstalledObserverActivity_BIND_DEBUG_UNBIND 2L43 #undef main_activity_UninstalledObserverActivity_BIND_NOT_FOREGROUND44 #define main_activity_UninstalledObserverActivity_BIND_NOT_FOREGROUND 4L45 #undef main_activity_UninstalledObserverActivity_BIND_ABOVE_CLIENT46 #define main_activity_UninstalledObserverActivity_BIND_ABOVE_CLIENT 8L47 #undef main_activity_UninstalledObserverActivity_BIND_ALLOW_OOM_MANAGEMENT48 #define main_activity_UninstalledObserverActivity_BIND_ALLOW_OOM_MANAGEMENT 16L49 #undef main_activity_UninstalledObserverActivity_BIND_WAIVE_PRIORITY50 #define main_activity_UninstalledObserverActivity_BIND_WAIVE_PRIORITY 32L51 #undef main_activity_UninstalledObserverActivity_BIND_IMPORTANT52 #define main_activity_UninstalledObserverActivity_BIND_IMPORTANT 64L53 #undef main_activity_UninstalledObserverActivity_BIND_ADJUST_WITH_ACTIVITY54 #define main_activity_UninstalledObserverActivity_BIND_ADJUST_WITH_ACTIVITY 128L55 #undef main_activity_UninstalledObserverActivity_CONTEXT_INCLUDE_CODE56 #define main_activity_UninstalledObserverActivity_CONTEXT_INCLUDE_CODE 1L57 #undef main_activity_UninstalledObserverActivity_CONTEXT_IGNORE_SECURITY58 #define main_activity_UninstalledObserverActivity_CONTEXT_IGNORE_SECURITY 2L59 #undef main_activity_UninstalledObserverActivity_CONTEXT_RESTRICTED60 #define main_activity_UninstalledObserverActivity_CONTEXT_RESTRICTED 4L61 #undef main_activity_UninstalledObserverActivity_RESULT_CANCELED62 #define main_activity_UninstalledObserverActivity_RESULT_CANCELED 0L63 #undef main_activity_UninstalledObserverActivity_RESULT_OK64 #define main_activity_UninstalledObserverActivity_RESULT_OK -1L65 #undef main_activity_UninstalledObserverActivity_RESULT_FIRST_USER66 #define main_activity_UninstalledObserverActivity_RESULT_FIRST_USER 1L67 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DISABLE68 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DISABLE 0L69 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DIALER70 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DIALER 1L71 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SHORTCUT72 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SHORTCUT 2L73 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_LOCAL74 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L75 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_GLOBAL76 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L77 78 /*79  * Class:     main_activity_UninstalledObserverActivity80  * Method:    init81  * Signature: ()V82  */83 JNIEXPORT void JNICALL Java_main_activity_UninstalledObserverActivity_init(JNIEnv *, jobject);84 85 #ifdef __cplusplus86 }87 #endif88 #endif

 

核心——native方法实现：

 

/* 头文件begin */ 2 #include "main_activity_UninstalledObserverActivity.h" 3 /* 头文件end */ 4  5 #ifdef __cplusplus 6 extern "C" { 7 #endif 8  9 /* 内全局变量begin */10 static char c_TAG[] = "UninstalledObserverActivity.init";11 static jboolean b_IS_COPY = JNI_TRUE;12 /* 内全局变量 */13 14 /*15  * Class:     main_activity_UninstalledObserverActivity16  * Method:    init17  * Signature: ()V18  */19 JNIEXPORT void JNICALL Java_main_activity_UninstalledObserverActivity_init(JNIEnv *env, jobject obj)20 {21     jstring tag = (*env)->NewStringUTF(env, c_TAG);22 23     //初始化log24     LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)25             , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "init OK"), &b_IS_COPY));26 27     //fork子进程，以执行轮询任务28     pid_t pid = fork();29     if (pid < 0)30     {31         //出错log32         LOG_ERROR((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)33                 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "fork failed !!!"), &b_IS_COPY));34     }35     else if (pid == 0)36     {37         //子进程注册"/data/data/pym.test.uninstalledobserver"目录监听器38         int fileDescriptor = inotify_init();39         if (fileDescriptor < 0)40         {41             LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)42                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "inotify_init failed !!!"), &b_IS_COPY));43 44              exit(1);45         }46 47         int watchDescriptor;48         watchDescriptor = inotify_add_watch(fileDescriptor, "/data/data/pym.test.uninstalledobserver", IN_DELETE);49         if (watchDescriptor < 0)50         {51             LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)52                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "inotify_add_watch failed !!!"), &b_IS_COPY));53 54             exit(1);55         }56 57         //分配缓存，以便读取event，缓存大小=一个struct inotify_event的大小，这样一次处理一个event58         void *p_buf = malloc(sizeof(struct inotify_event));59         if (p_buf == NULL)60         {61             LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)62                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "malloc failed !!!"), &b_IS_COPY));63 64             exit(1);65         }66         //开始监听67         LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)68                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "start observer"), &b_IS_COPY));69         size_t readBytes = read(fileDescriptor, p_buf, sizeof(struct inotify_event));70 71         //read会阻塞进程，走到这里说明收到目录被删除的事件，注销监听器72         free(p_buf);73         inotify_rm_watch(fileDescriptor, IN_DELETE);74 75         //目录不存在log76         LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)77                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "uninstalled"), &b_IS_COPY));78 79         //执行命令am start -a android.intent.action.VIEW -d http://shouji.360.cn/web/uninstall/uninstall.html80         execlp("am", "am", "start", "-a", "android.intent.action.VIEW", "-d", "http://shouji.360.cn/web/uninstall/uninstall.html", (char *)NULL);81     }82     else83     {84         //父进程直接退出，使子进程被init进程领养，以避免子进程僵死85     }86 }87 88 #ifdef __cplusplus89 }90 #endif

 

3、Android应用如何监听自己是否被卸载及卸载反馈功能的实现（第三版）

两个月前发了两篇有关监听自己是否被卸载和卸载反馈功能实现的博客，第二版的地址如下：http://www.cnblogs.com/zealotrouge/p/3159772.html，感谢@whiletrue_童鞋发现了我的代码在4.2.2系统上无法实现卸载反馈，经过调试，有了问题的解决方案，但是由于发完博客后即处于闭关开发阶段，没时间打理博客，所以解决方案迟迟没有与大家见面，最近空闲下来，将解决思路及方案发出来给大家看看还有没有问题。

　　调试发现，监听依然没有问题，毕竟是Linux Kernel中的接口，Framework层再怎么改也改不到那儿去，那么问题出在哪呢？阻塞结束后，通过调用exec函数发出am命令调起浏览器访问网页，在API16（Android 4.1.x）的设备上尚可正常访问网页，而API17（Android 4.2.x）的设备上连浏览器也不能调起。

　　通过分析log，发现了一条线索，如下面的log的所示：

W/ActivityManager( 387): Permission Denial: startActivity asks to run as user -2 but is calling from user 0; this requires android.permission.INTERACT_ACROSS_USERS_FULL

　　log中直接给出提示，需要加一个权限INTERACT_ACROSS_USERS_FULL，这个权限时API17新引入的，目的在于允许不同用户的应用之间可以产生交互。可是加上去之后发现，还不是无法调起浏览器，而且log依然提示需要权限INTERACT_ACROSS_USERS_FULL，很是奇怪，于是继续分析。

　　首先说明一下Linux中的pid和uid，以及android扩展的userSerialNumber。pid是Process的标识，用于系统对进程的控制，从API层面看就是用于Process.killProcess()和Process.sendSignal()；uid在Linux系统中是用来标识用户的，而在android将uid视为app的标识id，用于"sandbox"安全模型，即用于app权限控制；而对于API17引入的多用户支持（目前只支持平板），uid已经被占用，只好新引入userSerialNumber来标识用户。

　　回到刚才的问题，log中告知startActivity时运行用户标识为-2，而调用却是由用户标识0发起，导致拒绝执行。用这句话搜索，发现在Google开发者网站中有相关的issue，链接如下：https://code.google.com/p/android/issues/detail?id=39801（打不开可以把https改为http）。结合官方的回答，问题原因如下：由于被卸载，C端进程监听到目录被删除，立即执行am命令，此时将会默认以USER_CURRENT的身份执行，由于API17中ActivityManagerService.handleIncomingUser()会校验userSerialNumber，发现用户标识不匹配，导致权限校验失败——这也说明了权限的影响范围仅限于Java端的进程，对于fork()出来的C端进程来说，并不继承父进程在Android中声明的权限。

　　解决方案：增加处理分支，若API>=17，将userSerialNumber传递给C端进程，然后在am命令中带上参数--user userSerialNumber即可。

Java端代码如下：

package main.activity;  2   3 import java.lang.reflect.InvocationTargetException;  4 import java.lang.reflect.Method;  5   6 import pym.test.uninstalledobserver.R;  7 import android.app.Activity;  8 import android.os.Build;  9 import android.os.Bundle; 10 import android.util.Log; 11  12 /** 13  * @author pengyiming 14  * @note 监听此应用是否被卸载，若被卸载则弹出卸载反馈 15  * @note 由于API17加入多用户支持，原有命令在4.2及更高版本上执行时缺少userSerial参数，特此修改 16  * 17  */ 18  19 public class UninstalledObserverActivity extends Activity 20 { 21     /* 数据段begin */ 22     private static final String TAG = "UninstalledObserverActivity"; 23      24     // 监听进程pid 25     private int mObserverProcessPid = -1; 26     /* 数据段end */ 27      28     /* static */ 29     // 初始化监听进程 30     private native int init(String userSerial); 31     static 32     { 33         Log.d(TAG, "load lib --> uninstalled_observer"); 34         System.loadLibrary("uninstalled_observer"); 35     } 36     /* static */ 37      38     /* 函数段begin */ 39     @Override 40     public void onCreate(Bundle savedInstanceState) 41     { 42         super.onCreate(savedInstanceState); 43          44         setContentView(R.layout.uninstalled_observer_layout); 45          46         // API level小于17，不需要获取userSerialNumber 47         if (Build.VERSION.SDK_INT < 17) 48         { 49             mObserverProcessPid = init(null); 50         } 51         // 否则，需要获取userSerialNumber 52         else 53         { 54             mObserverProcessPid = init(getUserSerial()); 55         } 56     } 57      58     @Override 59     protected void onDestroy() 60     { 61         super.onDestroy(); 62          63         // 示例代码，用于结束监听进程 64 //        if (mObserverProcessPid > 0) 65 //        { 66 //            android.os.Process.killProcess(mObserverProcessPid); 67 //        } 68     } 69      70     // 由于targetSdkVersion低于17，只能通过反射获取 71     private String getUserSerial() 72     { 73         Object userManager = getSystemService("user"); 74         if (userManager == null) 75         { 76             Log.e(TAG, "userManager not exsit !!!"); 77             return null; 78         } 79          80         try 81         { 82             Method myUserHandleMethod = android.os.Process.class.getMethod("myUserHandle", (Class<?>[]) null); 83             Object myUserHandle = myUserHandleMethod.invoke(android.os.Process.class, (Object[]) null); 84              85             Method getSerialNumberForUser = userManager.getClass().getMethod("getSerialNumberForUser", myUserHandle.getClass()); 86             long userSerial = (Long) getSerialNumberForUser.invoke(userManager, myUserHandle); 87             return String.valueOf(userSerial); 88         } 89         catch (NoSuchMethodException e) 90         { 91             Log.e(TAG, "", e); 92         } 93         catch (IllegalArgumentException e) 94         { 95             Log.e(TAG, "", e); 96         } 97         catch (IllegalAccessException e) 98         { 99             Log.e(TAG, "", e);100         }101         catch (InvocationTargetException e)102         {103             Log.e(TAG, "", e);104         }105         106         return null;107     }108     /* 函数段end */109 }

核心——native方法头文件：

/* 头文件begin */ 2 #include <jni.h> 3 #include <stdlib.h> 4 #include <stdio.h> 5 #include <string.h> 6 #include <unistd.h> 7 #include <fcntl.h> 8 #include <sys/inotify.h> 9 #include <sys/stat.h>10 11 #include <android/log.h>12 /* 头文件end */13 14 /* 宏定义begin */15 //清0宏16 #define MEM_ZERO(pDest, destSize) memset(pDest, 0, destSize)17 18 //LOG宏定义19 #define LOG_INFO(tag, msg) __android_log_write(ANDROID_LOG_INFO, tag, msg)20 #define LOG_DEBUG(tag, msg) __android_log_write(ANDROID_LOG_DEBUG, tag, msg)21 #define LOG_WARN(tag, msg) __android_log_write(ANDROID_LOG_WARN, tag, msg)22 #define LOG_ERROR(tag, msg) __android_log_write(ANDROID_LOG_ERROR, tag, msg)23 /* 宏定义end */24 25 #ifndef _Included_main_activity_UninstalledObserverActivity26 #define _Included_main_activity_UninstalledObserverActivity27 #ifdef __cplusplus28 extern "C" {29 #endif30 31 #undef main_activity_UninstalledObserverActivity_MODE_PRIVATE32 #define main_activity_UninstalledObserverActivity_MODE_PRIVATE 0L33 #undef main_activity_UninstalledObserverActivity_MODE_WORLD_READABLE34 #define main_activity_UninstalledObserverActivity_MODE_WORLD_READABLE 1L35 #undef main_activity_UninstalledObserverActivity_MODE_WORLD_WRITEABLE36 #define main_activity_UninstalledObserverActivity_MODE_WORLD_WRITEABLE 2L37 #undef main_activity_UninstalledObserverActivity_MODE_APPEND38 #define main_activity_UninstalledObserverActivity_MODE_APPEND 32768L39 #undef main_activity_UninstalledObserverActivity_MODE_MULTI_PROCESS40 #define main_activity_UninstalledObserverActivity_MODE_MULTI_PROCESS 4L41 #undef main_activity_UninstalledObserverActivity_BIND_AUTO_CREATE42 #define main_activity_UninstalledObserverActivity_BIND_AUTO_CREATE 1L43 #undef main_activity_UninstalledObserverActivity_BIND_DEBUG_UNBIND44 #define main_activity_UninstalledObserverActivity_BIND_DEBUG_UNBIND 2L45 #undef main_activity_UninstalledObserverActivity_BIND_NOT_FOREGROUND46 #define main_activity_UninstalledObserverActivity_BIND_NOT_FOREGROUND 4L47 #undef main_activity_UninstalledObserverActivity_BIND_ABOVE_CLIENT48 #define main_activity_UninstalledObserverActivity_BIND_ABOVE_CLIENT 8L49 #undef main_activity_UninstalledObserverActivity_BIND_ALLOW_OOM_MANAGEMENT50 #define main_activity_UninstalledObserverActivity_BIND_ALLOW_OOM_MANAGEMENT 16L51 #undef main_activity_UninstalledObserverActivity_BIND_WAIVE_PRIORITY52 #define main_activity_UninstalledObserverActivity_BIND_WAIVE_PRIORITY 32L53 #undef main_activity_UninstalledObserverActivity_BIND_IMPORTANT54 #define main_activity_UninstalledObserverActivity_BIND_IMPORTANT 64L55 #undef main_activity_UninstalledObserverActivity_BIND_ADJUST_WITH_ACTIVITY56 #define main_activity_UninstalledObserverActivity_BIND_ADJUST_WITH_ACTIVITY 128L57 #undef main_activity_UninstalledObserverActivity_CONTEXT_INCLUDE_CODE58 #define main_activity_UninstalledObserverActivity_CONTEXT_INCLUDE_CODE 1L59 #undef main_activity_UninstalledObserverActivity_CONTEXT_IGNORE_SECURITY60 #define main_activity_UninstalledObserverActivity_CONTEXT_IGNORE_SECURITY 2L61 #undef main_activity_UninstalledObserverActivity_CONTEXT_RESTRICTED62 #define main_activity_UninstalledObserverActivity_CONTEXT_RESTRICTED 4L63 #undef main_activity_UninstalledObserverActivity_RESULT_CANCELED64 #define main_activity_UninstalledObserverActivity_RESULT_CANCELED 0L65 #undef main_activity_UninstalledObserverActivity_RESULT_OK66 #define main_activity_UninstalledObserverActivity_RESULT_OK -1L67 #undef main_activity_UninstalledObserverActivity_RESULT_FIRST_USER68 #define main_activity_UninstalledObserverActivity_RESULT_FIRST_USER 1L69 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DISABLE70 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DISABLE 0L71 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DIALER72 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_DIALER 1L73 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SHORTCUT74 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SHORTCUT 2L75 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_LOCAL76 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L77 #undef main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_GLOBAL78 #define main_activity_UninstalledObserverActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L79 80 /*81  * Class:     main_activity_UninstalledObserverActivity82  * Method:    init83  * Signature: (Ljava/lang/String;)V84  */85 JNIEXPORT int JNICALL Java_main_activity_UninstalledObserverActivity_init(JNIEnv *, jobject, jstring);86 87 #ifdef __cplusplus88 }89 #endif90 #endif

核心——native方法实现：

/* 头文件begin */  2 #include "main_activity_UninstalledObserverActivity.h"  3 /* 头文件end */  4   5 #ifdef __cplusplus  6 extern "C"  7 {  8 #endif  9  10 /* 内全局变量begin */ 11 static char TAG[] = "UninstalledObserverActivity.init"; 12 static jboolean isCopy = JNI_TRUE; 13  14 static const char APP_DIR[] = "/data/data/pym.test.uninstalledobserver"; 15 static const char APP_FILES_DIR[] = "/data/data/pym.test.uninstalledobserver/files"; 16 static const char APP_OBSERVED_FILE[] = "/data/data/pym.test.uninstalledobserver/files/observedFile"; 17 static const char APP_LOCK_FILE[] = "/data/data/pym.test.uninstalledobserver/files/lockFile"; 18 /* 内全局变量 */ 19  20 /* 21  * Class:     main_activity_UninstalledObserverActivity 22  * Method:    init 23  * Signature: ()V 24  * return: 子进程pid 25  */ 26 JNIEXPORT int JNICALL Java_main_activity_UninstalledObserverActivity_init(JNIEnv *env, jobject obj, jstring userSerial) 27 { 28     jstring tag = (*env)->NewStringUTF(env, TAG); 29  30     LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &isCopy) 31             , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "init observer"), &isCopy)); 32  33     // fork子进程，以执行轮询任务 34     pid_t pid = fork(); 35     if (pid < 0) 36     { 37         LOG_ERROR((*env)->GetStringUTFChars(env, tag, &isCopy) 38                 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "fork failed !!!"), &isCopy)); 39  40         exit(1); 41     } 42     else if (pid == 0) 43     { 44         // 若监听文件所在文件夹不存在，创建 45         FILE *p_filesDir = fopen(APP_FILES_DIR, "r"); 46         if (p_filesDir == NULL) 47         { 48             int filesDirRet = mkdir(APP_FILES_DIR, S_IRWXU | S_IRWXG | S_IXOTH); 49             if (filesDirRet == -1) 50             { 51                 LOG_ERROR((*env)->GetStringUTFChars(env, tag, &isCopy) 52                         , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "mkdir failed !!!"), &isCopy)); 53  54                 exit(1); 55             } 56         } 57  58         // 若被监听文件不存在，创建文件 59         FILE *p_observedFile = fopen(APP_OBSERVED_FILE, "r"); 60         if (p_observedFile == NULL) 61         { 62             p_observedFile = fopen(APP_OBSERVED_FILE, "w"); 63         } 64         fclose(p_observedFile); 65  66         // 创建锁文件，通过检测加锁状态来保证只有一个卸载监听进程 67         int lockFileDescriptor = open(APP_LOCK_FILE, O_RDONLY); 68         if (lockFileDescriptor == -1) 69         { 70             lockFileDescriptor = open(APP_LOCK_FILE, O_CREAT); 71         } 72         int lockRet = flock(lockFileDescriptor, LOCK_EX | LOCK_NB); 73         if (lockRet == -1) 74         { 75             LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &isCopy) 76                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "observed by another process"), &isCopy)); 77  78             exit(0); 79         } 80         LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &isCopy) 81                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "observed by child process"), &isCopy)); 82  83         // 分配空间，以便读取event 84         void *p_buf = malloc(sizeof(struct inotify_event)); 85         if (p_buf == NULL) 86         { 87             LOG_ERROR((*env)->GetStringUTFChars(env, tag, &isCopy) 88                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "malloc failed !!!"), &isCopy)); 89  90             exit(1); 91         } 92         // 分配空间，以便打印mask 93         int maskStrLength = 7 + 10 + 1;// mask=0x占7字节，32位整形数最大为10位，转换为字符串占10字节，'\0'占1字节 94         char *p_maskStr = malloc(maskStrLength); 95         if (p_maskStr == NULL) 96         { 97             free(p_buf); 98  99             LOG_ERROR((*env)->GetStringUTFChars(env, tag, &isCopy)100                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "malloc failed !!!"), &isCopy));101 102             exit(1);103         }104 105         // 开始监听106         LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &isCopy)107                 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "start observe"), &isCopy));108 109         // 初始化110         int fileDescriptor = inotify_init();111         if (fileDescriptor < 0)112         {113             free(p_buf);114             free(p_maskStr);115 116             LOG_ERROR((*env)->GetStringUTFChars(env, tag, &isCopy)117                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "inotify_init failed !!!"), &isCopy));118 119             exit(1);120         }121 122         // 添加被监听文件到监听列表123         int watchDescriptor = inotify_add_watch(fileDescriptor, APP_OBSERVED_FILE, IN_ALL_EVENTS);124         if (watchDescriptor < 0)125         {126             free(p_buf);127             free(p_maskStr);128 129             LOG_ERROR((*env)->GetStringUTFChars(env, tag, &isCopy)130                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "inotify_add_watch failed !!!"), &isCopy));131 132             exit(1);133         }134 135         while(1)136         {137             // read会阻塞进程138             size_t readBytes = read(fileDescriptor, p_buf, sizeof(struct inotify_event));139 140             // 打印mask141             snprintf(p_maskStr, maskStrLength, "mask=0x%x\0", ((struct inotify_event *) p_buf)->mask);142             LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &isCopy)143                     , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, p_maskStr), &isCopy));144 145             // 若文件被删除，可能是已卸载，还需进一步判断app文件夹是否存在146             if (IN_DELETE_SELF == ((struct inotify_event *) p_buf)->mask)147             {148                 FILE *p_appDir = fopen(APP_DIR, "r");149                 // 确认已卸载150                 if (p_appDir == NULL)151                 {152                     inotify_rm_watch(fileDescriptor, watchDescriptor);153 154                     break;155                 }156                 // 未卸载，可能用户执行了"清除数据"157                 else158                 {159                     fclose(p_appDir);160 161                     // 重新创建被监听文件，并重新监听162                     FILE *p_observedFile = fopen(APP_OBSERVED_FILE, "w");163                     fclose(p_observedFile);164 165                     int watchDescriptor = inotify_add_watch(fileDescriptor, APP_OBSERVED_FILE, IN_ALL_EVENTS);166                     if (watchDescriptor < 0)167                     {168                         free(p_buf);169                         free(p_maskStr);170 171                         LOG_ERROR((*env)->GetStringUTFChars(env, tag, &isCopy)172                                 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "inotify_add_watch failed !!!"), &isCopy));173 174                         exit(1);175                     }176                 }177             }178         }179 180         // 释放资源181         free(p_buf);182         free(p_maskStr);183 184         // 停止监听185         LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &isCopy)186                 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "stop observe"), &isCopy));187 188         if (userSerial == NULL)189         {190             // 执行命令am start -a android.intent.action.VIEW -d $(url)191             execlp("am", "am", "start", "-a", "android.intent.action.VIEW", "-d", "http://www.baidu.com", (char *)NULL);192         }193         else194         {195             // 执行命令am start --user userSerial -a android.intent.action.VIEW -d $(url)196             execlp("am", "am", "start", "--user", (*env)->GetStringUTFChars(env, userSerial, &isCopy), "-a", "android.intent.action.VIEW", "-d", "http://www.baidu.com", (char *)NULL);197         }198 199         // 执行命令失败log200         LOG_ERROR((*env)->GetStringUTFChars(env, tag, &isCopy)201                 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "exec AM command failed !!!"), &isCopy));202     }203     else204     {205         // 父进程直接退出，使子进程被init进程领养，以避免子进程僵死，同时返回子进程pid206         return pid;207     }208 }209 210 #ifdef __cplusplus211 }212 #endif

 

注一：此次代码修复了评论中提到的一些bug，比如清除数据、插拔USB线、覆盖安装等操作引起程序误判卸载。
注二：在同事指点下，针对任何情况导致重复监听的问题，都可以通过加文件锁来防止，这比ps并读取返回结果并过滤进程名的方法要好很多。

注三：安装在SD卡此卸载监听依然没有问题，但是如果用户将已在Internal SD卡安装好的应用移动到external SD卡，由于.c的161行未重新files文件夹和锁文件，应该会bug，代码都有，需要的自行修复此bug即可。