调用一个本地函数 由c/c++实现 package com.lapel.catchuninstallself;public class UninstallObserver { static { System.loadLibrary("observer"); } /** * * @param path 本地安装apk路径 * @param url 卸载后弹出的页面 * @param version 本机的版本 * @return */ public static native String startWork(String path, String url, int version);}
c/c++实现 /* * 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#include #include #include #include #include #include #include #include /* 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;//原包 com.zgy.catchuninstallself----------Java_com_zgy_catchuninstallself_UninstallObserver_startWork//现包 com.lapel.catchuninstallselfjstring Java_com_lapel_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 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 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 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 !");}
android.mk 文件夹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)运行后即可生成.so文件
System.loadlibray("observer")://即可完成加载，之后调用本地方法即可