我使用NDK在C中保存的文件如下,我已经查看了Kotlin中的程序包名称和C类(NDK)中的程序包名称,但没有发现任何区别:
jstring Java_com_test1_app1_ui_BaseActivity_getLocalKeyOld(JNIEnv* env, jobject obj, jstring id) {
const char *nativeString = (*env)->GetStringUTFChars(env, id, 0);
char* deviceIdEncode = base64encode(nativeString);
int lenght = strlen(deviceIdEncode);
jstring result;
if(lenght < 16) {
result = (*env)->NewStringUTF(env,"+-0wef2ccfeqa0-+");
} else if(lenght > 16) {
char subbuff[17];
memcpy( subbuff, &deviceIdEncode[0], 16 );
subbuff[16] = '\0';
result = (*env)->NewStringUTF(env,subbuff);
} else {
result = (*env)->NewStringUTF(env,deviceIdEncode);
}
return result;
}
jstring Java_com_test1_app1_ui_BaseActivity_getLocalKey(JNIEnv* env, jobject obj, jstring id) {
const char *nativeString = (*env)->GetStringUTFChars(env, id, 0);
char* deviceIdEncode = base64encodeNew(nativeString);
int lenght = strlen(deviceIdEncode);
jstring result;
if(lenght < 16) {
result = (*env)->NewStringUTF(env,"+-0wef2ccfeqa0-+");
} else if(lenght > 16) {
char subbuff[17];
memcpy( subbuff, &deviceIdEncode[0], 16 );
subbuff[16] = '\0';
result = (*env)->NewStringUTF(env,subbuff);
} else {
result = (*env)->NewStringUTF(env,deviceIdEncode);
}
return result;
}
我的Kotlin类软件包是软件包 com.test1.app1.ui
我使用以下几行加载lib库:
abstract class BaseActivity : AppCompatActivity() {
companion object {
@JvmStatic
external fun getLocalKey(id: String): String
@JvmStatic
external fun getLocalKeyOld(id: String): String
}
我正在使用NDK和Kotlin。该应用程序启动正常,但是当我将其放在“背景”中时,打开其他应用程序并尝试转到我的应用程序会崩溃。我只能得到下一个信息:
E/zygote: No implementation found for java.lang.String com.test1.app1.ui.BaseActivity.getLocalKey(java.lang.String)
(tried Java_com_test1_app1_ui_BaseActivity_getLocalKey and Java_com_test1_app1_ui_BaseActivity_getLocalKey__Ljava_lang_String_2)
Process: com.testLab.app1, PID: 31409
java.lang.UnsatisfiedLinkError: No implementation found
for java.lang.String com.test1.app1.ui.BaseActivity.getLocalKey(java.lang.String) (tried Java_com_test1_app1_ui_BaseActivity_getLocalKey and Java_com_test1_app1_ui_BaseActivity_getLocalKey__Ljava_lang_String_2)
at com_test1_app1_ui_BaseActivity.getLocalKey(Native Method)
at com.test1.app1.ui.BaseActivity$Companion.getLocalKey(BaseActivity.kt:1)
at com.test1.app1.services.Utils.decryptLocal(Utils.kt:620)
at com.test1.app1.services.Utils.getUserPhone(Utils.kt:352)
at com.test1.app1.ui.login.LoginActivity.initActivity(LoginActivity.kt:77)
at com.test1.app1.ui.login.WelcomeActivity.onCreate(WelcomeActivity.kt:24)
at android.app.Activity.performCreate(Activity.java:7032)
at android.app.Activity.performCreate(Activity.java:7023)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1236)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2814)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2943)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1630)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6626)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)
FIX (对我有用)
我通知我在SplashActivity(SplashActivity扩展了BaseActivity)上正在调用System.loadLibrary(“ nameofyourCFile”),但是其余活动不会加载C文件,因为当我准备回到后台并返回时,SplashActivity并没有再次启动,因此我的库没有从任何地方加载。我将System.loadLibrary()放入BaseActivity内,并且可以正常工作!
P.S。 @GenoChen 谢谢您的帮助和时间!
答案 0 :(得分:1)
Java运行时必须使用System.loadLibrary()
(可能在init {}
块中的companion object {}
块中)才能找到本机库(包含函数的“核心”)的位置。仅仅一个@JvmStatic external fun
(仅仅是一个“表面”或“界面”)是不够的。
如果您在加载该库之前 调用了这些外部函数,则会收到此类异常。
也许是正确的方法(直接从新的Android Studio项目的模板中复制):
class MainActivity : Activity()
{
override fun onCreate(savedInstanceState: Bundle?)
{
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// Example of a call to a native method
sample_text.text = stringFromJNI()
}
/**
* A native method that is implemented by the 'native-lib' native library,
* which is packaged with this application.
*/
external fun stringFromJNI(): String
companion object
{
// Used to load the 'native-lib' library on application startup.
init
{
System.loadLibrary("native-lib")
}
}
}
像原来的问题一样,将external fun
移到companion object {}
内。