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POTrying to add second C++ file. Android JNI: UnsatisfiedLinkError - Can't find native method
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copied!<p>So I'm playing around with JNI to see what its limitations are in terms of system calls. My first C file to just learn how JNI works still runs perfectly. I'm trying to add another C++ file that reads uname and concatenates into a single string then return. However the linker can't actually find the new function definition (getKernelInfo()). I've tried the obvious like double checking the types and the name of the function/java packages. However I can't seem to find the issue.</p> <p>Here are the relevant files:</p> <p>Android.mk</p> <pre><code>LOCAL_PATH:= $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE := example LOCAL_CFLAGS := -Werror LOCAL_SRC_FILES := \ example.c \ kernel.cpp LOCAL_LDLIBS := -llog include $(BUILD_SHARED_LIBRARY) </code></pre> <p>Application.mk</p> <pre><code>APP_STL := stlport_static </code></pre> <p>kernel.cpp</p> <pre><code>#include <jni.h> #include <sys/utsname.h> #include <string> using namespace std; JNIEXPORT jstring JNICALL Java_com_test_myjniapp_MainActivity_getKernelInfo(JNIEnv * env, jobject obj) { struct utsname info; uname(&info); string sysInfo = ""; char** names = (char**)&(info.sysname); for(int i = 0; i < 5; i++, names++) { sysInfo = sysInfo + string(*names); if(i != 4) sysInfo = sysInfo + ", "; } jstring res = env->NewStringUTF((const char*)sysInfo.c_str()); return res; } </code></pre> <p>MainActivity.java</p> <pre><code>package com.test.myjniapp; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.view.View; import android.widget.Button; import android.widget.TextView; public class MainActivity extends Activity { static { System.loadLibrary("example"); } private TextView textUID; private Button btnPress; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); textUID = (TextView) findViewById(R.id.txtUID); btnPress = (Button) findViewById(R.id.btnUID); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } public void onUIDClick(View v) { textUID.setText(Integer.toString(getUID())); } public void onPIDClick(View v) { textUID.setText(Integer.toString(getPID())); } public void onTimeClick(View v) { textUID.setText(Long.toString(getTime())); } public void onKernelClick(View v) { textUID.setText(getKernelInfo()); } private native int getUID(); private native int getPID(); private native long getTime(); private native String getKernelInfo(); } </code></pre>

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