//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;
jstring
Java_com_example_uninstallself_Observer_register(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。以运行轮询任务
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)
{
//子进程注冊文件夹监听器
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);
}
//開始监听
LOG_DEBUG((*env)->GetStringUTFChars(env,
tag,
&b_IS_COPY),
(*env)->GetStringUTFChars(env,
(*env)->NewStringUTF(env,
"start observer"),
&b_IS_COPY));
//read会堵塞进程，
size_t readBytes
= read(fileDescriptor,
p_buf,
sizeof(struct
inotify_event));
//走到这里说明收到文件夹被删除的事件。注销监听器
free(p_buf);
inotify_rm_watch(fileDescriptor,
IN_DELETE);
//文件夹不存在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以上的系统因为用户权限管理更严格，须要加上 --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：能够运行其它shell命令，am(即activity manager)，能够打开某程序、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 !");
}
