Android研究之监听自身应用被卸载代码实现

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//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 !");

}

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public
class UninstallObserver
{

static{

System.loadLibrary("observer");

}

/***

*

* @param path 须要监听的文件路径。可用 getApplicationContext().getFilesDir().getPath()

* @param url 卸载调转http

* @param version android.os.Build.VERSION.SDK_INT

* @return

*/

public
static native
String register(String
path,
String url,
int version);

}

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@Override

protected void
onCreate(Bundle
savedInstanceState)
{

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

Toast.makeText(getApplicationContext(),

getApplicationContext().getFilesDir().getPath()
+ ","
+ Build.VERSION.SDK_INT,
1).show();

long
a =
System.currentTimeMillis();

String
str =
UninstallObserver.register(getApplicationContext().getFilesDir().getPath(),
"http://www.baidu.com",

android.os.Build.VERSION.SDK_INT);

long
b =
System.currentTimeMillis();

Toast.makeText(getApplicationContext(),
str+","+(b-a),
1).show();

}