我正在开发一个Android应用程序，我正在使用NDK库，一切正常。在清理项目时，我收到了这个警告：
Android NDK：警告：APP_PLATFORM android-21比./AndroidManifest.xml中的android：minSdkVersion 3大
当我访问我的活动以查看我的本机代码的结果时，我得到以下异常：
05-10 13:01:33.001: E/AndroidRuntime(15024): java.lang.UnsatisfiedLinkError: Native method not found: com.zitza.murncy.activities.HelloJni.stringFromJNI:()Ljava/lang/String;
05-10 13:01:33.001: E/AndroidRuntime(15024): at com.zitza.murncy.activities.HelloJni.stringFromJNI(Native Method)
05-10 13:01:33.001: E/AndroidRuntime(15024): at com.zitza.murncy.activities.HelloJni.onCreate(HelloJni.java:36)
我的活动类以及头文件和清单如下所示。
我的HelloJni课程
package zitza.murncy.activities;
import android.app.Activity;
import android.widget.TextView;
import android.os.Bundle;
public class HelloJni extends Activity
{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
/* Create a TextView and set its content.
* the text is retrieved by calling a native
* function.
*/
TextView tv = new TextView(this);
tv.setText( stringFromJNI() );
setContentView(tv);
}
/* A native method that is implemented by the
* 'hello-jni' native library, which is packaged
* with this application.
*/
public native String stringFromJNI();
/* This is another native method declaration that is *not*
* implemented by 'hello-jni'. This is simply to show that
* you can declare as many native methods in your Java code
* as you want, their implementation is searched in the
* currently loaded native libraries only the first time
* you call them.
*
* Trying to call this function will result in a
* java.lang.UnsatisfiedLinkError exception !
*/
public native String unimplementedStringFromJNI();
/* this is used to load the 'hello-jni' library on application
* startup. The library has already been unpacked into
* /data/data/com.example.hellojni/lib/libhello-jni.so at
* installation time by the package manager.
*/
static {
System.loadLibrary("hello-jni");
}
}
我的Android.mk文件
# 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.
#
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := hello-jni
LOCAL_SRC_FILES := hello-jni.c
include $(BUILD_SHARED_LIBRARY)
我的Application.mk文件
APP_ABI := all
我的hello-jni.c
#include <string.h>
#include <jni.h>
/* This is a trivial JNI example where we use a native method
* to return a new VM String. See the corresponding Java source
* file located at:
*
* apps/samples/hello-jni/project/src/com/example/hellojni/HelloJni.java
*/
jstring
Java_com_example_hellojni_HelloJni_stringFromJNI( JNIEnv* env,
jobject thiz )
{
#if defined(__arm__)
#if defined(__ARM_ARCH_7A__)
#if defined(__ARM_NEON__)
#if defined(__ARM_PCS_VFP)
#define ABI "armeabi-v7a/NEON (hard-float)"
#else
#define ABI "armeabi-v7a/NEON"
#endif
#else
#if defined(__ARM_PCS_VFP)
#define ABI "armeabi-v7a (hard-float)"
#else
#define ABI "armeabi-v7a"
#endif
#endif
#else
#define ABI "armeabi"
#endif
#elif defined(__i386__)
#define ABI "x86"
#elif defined(__x86_64__)
#define ABI "x86_64"
#elif defined(__mips64) /* mips64el-* toolchain defines __mips__ too */
#define ABI "mips64"
#elif defined(__mips__)
#define ABI "mips"
#elif defined(__aarch64__)
#define ABI "arm64-v8a"
#else
#define ABI "unknown"
#endif
return (*env)->NewStringUTF(env, "AIzaSUhfkedpl0AS8" ABI ".");
}
我的清单文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.murncy"
android:versionCode="3"
android:versionName="3.0" >
<!-- <uses-sdk android:minSdkVersion="3" /> -->
<uses-sdk
android:minSdkVersion="10"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.SEND_SMS" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.GET_TASKS" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_CONTACTS" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<!-- If c2dm permission is removed, parse starts working, else c2dm takes control -->
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<permission
android:name="com.murgency.permission.C2D_MESSAGE"
android:protectionLevel="signature" />
<uses-permission android:name="com.murncy.permission.C2D_MESSAGE" />
<application
android:name="com.zitza.murncy.MUrgencyApplication"
android:allowBackup="true"
android:icon="@drawable/icon"
android:label="@string/app_name"
android:theme="@style/Sherlock.__Theme.Light" >
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="AIzaSyAiJ3CMj_kKyjgWa-tNSLjUhfkedpl0AS8" />
<meta-data
android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version" />
<activity
android:name="com.zitza.murncy.activities.HelloJni"
android:label="Testing Native Code"
android:screenOrientation="portrait" />
<activity
android:name="com.zitza.murncy.activities.SplashScreen"
android:screenOrientation="portrait"
android:theme="@style/AppTheme"
android:windowSoftInputMode="stateAlwaysHidden" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!-- Contact change listener on boot -->
<service android:name="com.zitza.services.ContactService" />
<receiver
android:name="com.zitza.services.BootReceiver"
android:enabled="true"
android:exported="false" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
<service android:name="com.zitza.services.ContactService" />
<service
android:name="com.zitza.services.GPSLoggerService"
android:enabled="true"
android:exported="true"
android:permission="android.permission.ACCESS_FINE_LOCATION" >
</service>
<!-- Parse push -->
<service android:name="com.parse.PushService" />
<!-- <receiver -->
<!-- android:name="com.parse.GcmBroadcastReceiver" -->
<!-- android:permission="com.google.android.c2dm.permission.SEND" > -->
<!-- <intent-filter> -->
<!-- <action android:name="com.google.android.c2dm.intent.RECEIVE" /> -->
<!-- <action android:name="com.google.android.c2dm.intent.REGISTRATION" /> -->
<!-- <category android:name="com.murgency" /> -->
<!-- </intent-filter> -->
<!-- </receiver> -->
<receiver android:name="com.parse.ParseBroadcastReceiver" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<action android:name="android.intent.action.USER_PRESENT" />
</intent-filter>
</receiver>
<!-- Custom receiver -->
<!-- <receiver -->
<!-- android:name="com.zitza.services.ParsePushReceiver" -->
<!-- android:exported="false" > -->
<!-- <intent-filter> -->
<!-- <action android:name="android.intent.action.BOOT_COMPLETED" /> -->
<!-- <action android:name="android.intent.action.USER_PRESENT" /> -->
<!-- <action android:name="com.murgency.UPDATE_STATUS" /> -->
<!-- </intent-filter> -->
<!-- </receiver> -->
<!-- GCM -->
<service
android:name="com.zitza.services.GcmIntentService"
android:enabled="true" />
<receiver
android:name="com.zitza.services.GcmBroadcastReceiver"
android:permission="com.google.android.c2dm.permission.RECEIVE" >
<intent-filter android:priority="1" >
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<action android:name="com.murncy.UPDATE_STATUS" />
<category android:name="com.murncy" />
</intent-filter>
</receiver>
</application>
</manifest>
答案 0 :(得分：1)
要获取本机功能的正确签名，您可以自动创建JNI标头：
/* JNI header: this header can be build automatically with "javah":
* javah -classpath bin/classes -d jni activities.murncy.zitza.HelloJni
* (maybe you have to add "-bootclasspath /opt/android-sdk/platforms/android-21/android.jar")
*/
#include "activities_murncy_zitza_HelloJni.h"
要避免此警告，您可以将以下内容添加到Application.mk：
# minimium Android version
APP_PLATFORM := android-10
修改
javah -bootclasspath /opt/android-sdk/platforms/android-10/android.jar -classpath bin/classes -d jni activities.murncy.zitza.HelloJni
（当然，您必须调整安装Android SDK的路径）