Android应用被卸载后，自动使用 浏览器打开指定联接

本文，提供“Android应用被卸载后，自动使用 浏览器打开指定连接”的方法。
原理：在安卓程序中某处，基于JNI调用C代码开启一个子进程监控应用在系统中的文件目录，一旦应用被卸载，该目录将会被系统删除，此时触发子进程执行相关代码（本例调用浏览器执行打开一个连接）
1、在安卓项目下创建jni目录
2、在jni目录下创建文件observer.c

/* * Copyright (C) 2009 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may 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 <string.h>#include <jni.h>#include <jni.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <android/log.h>#include <unistd.h>#include <sys/inotify.h>/* 宏定义begin *///清0宏#define MEM_ZERO(pDest, destSize) memset(pDest, 0, destSize)//LOG宏定义#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)/* 内全局变量begin */static char c_TAG[] = "onEvent";static jboolean b_IS_COPY = JNI_TRUE;/* 暴露给Android代码调用的natvie方法 */jstring Java_com_zgy_catchuninstallself_UninstallObserver_startWork(JNIEnv* env,        jobject thiz, jstring path, jstring url, jint version) {    jstring tag = (*env)->NewStringUTF(env, c_TAG);    //初始化log    LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY),            (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "init OK"),                    &b_IS_COPY));    //fork子进程，以执行轮询任务    pid_t pid = fork();    if (pid < 0) {        //出错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) {        //子进程注册目录监听器        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);        }        //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);        }        //开始监听        LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY),                (*env)->GetStringUTFChars(env,                        (*env)->NewStringUTF(env, "start observer"),                        &b_IS_COPY));        //read会阻塞进程，        size_t readBytes = read(fileDescriptor, p_buf,                sizeof(struct inotify_event));        //走到这里说明收到目录被删除的事件，注销监听器        free(p_buf);        inotify_rm_watch(fileDescriptor, IN_DELETE);        //目录不存在log        LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY),                (*env)->GetStringUTFChars(env,                        (*env)->NewStringUTF(env, "uninstalled"), &b_IS_COPY));        if (version >= 17) {            //4.2以上的系统由于用户权限管理更严格，需要加上 --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);        }        //扩展：可以执行其他shell命令，am(即activity manager)，可以打开某程序、服务，broadcast intent，等等    } else {        //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    }    return (*env)->NewStringUTF(env, "Hello from JNI !");}

3、在jni目录下创建文件Android.mk

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、在创建natvie方法，并在Android中调用JNI方法

package com.zgy.catchuninstallself;public class UninstallObserver {    static{        System.loadLibrary("observer");    }    public static native String startWork(String path, String url, int version);//path：data/data/[packageNmae]   ；   url:跳转的页面，需要http://或https://开头}

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

注：JNI方法在被重复调用的情况下，我没有测试是否会重复开启多个子进程，这个留给大家测试。