添加jni时出现如下问题
log 如下
01-07 17:34:51.406 W/dalvikvm( 2032): JNI_OnLoad returned bad version (-1) in /system/lib/libengfetch_jni.so 0x423fcc30
01-07 17:34:51.406 D/wll ( 2032): load libtesterstatus_jni error!
01-07 17:34:51.406 W/dalvikvm( 2032): No implementation found for native Lcom/huaqin/runtime/engtools/engfetch;.engf_writephasecheck:(II)V
01-07 17:34:51.406 D/AndroidRuntime( 2032): Shutting down VM
01-07 17:34:51.406 W/dalvikvm( 2032): threadid=1: thread exiting with uncaught exception (group=0x41cdc378)
01-07 17:34:51.406 I/ ( 2032): JNI_OnLoad
01-07 17:34:51.406 E/ ( 2032): RegisterNatives failed for 'com/huaqin/runtime/engtools/engfetch'
01-07 17:34:51.406 E/ ( 2032): ERROR: registerNatives failed
01-07 17:34:51.406 E/AndroidRuntime( 2032): FATAL EXCEPTION: main
01-07 17:34:51.406 E/AndroidRuntime( 2032): java.lang.UnsatisfiedLinkError: Native method not found: com.huaqin.runtime.engtools.engfetch.engf_writephasecheck:(II)V
01-07 17:34:51.406 E/AndroidRuntime( 2032): at com.huaqin.runtime.engtools.engfetch.engf_writephasecheck(Native Method)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at com.huaqin.runtime.engtools.engfetch.engwritephasecheck(engfetch.java:124)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at com.huaqin.runtime.RuntimeTestTesting.RuntimeTestTestingResultSave(RuntimeTestTesting.java:196)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at com.huaqin.runtime.RuntimeTestTesting.access$2000(RuntimeTestTesting.java:42)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at com.huaqin.runtime.RuntimeTestTesting$3.onReceive(RuntimeTestTesting.java:316)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:755)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at android.os.Handler.handleCallback(Handler.java:615)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at android.os.Handler.dispatchMessage(Handler.java:92)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at android.os.Looper.loop(Looper.java:137)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at android.app.ActivityThread.main(ActivityThread.java:4990)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at java.lang.reflect.Method.invokeNative(Native Method)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at java.lang.reflect.Method.invoke(Method.java:511)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:807)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:574)
01-07 17:34:51.406 E/AndroidRuntime( 2032): at dalvik.system.NativeStart.main(Native Method)
01-07 17:34:51.416 W/ActivityManager( 449): Force finishing activity com.huaqin.runtime/.RuntimeTestTesting
.........
网上搜索可能是proguard问题引起的。
判断出在编译的时候系统做了优化，把无用的代码做了过滤(engf_writephasecheck )。好，那我就在编译时强制保留此方法，了解到Android系统编译是用ProGuard来进行代码优化和混淆工作的，OK，参照别的Android.mk文件加了参数：
LOCAL_PROGUARD_FLAG_FILES := proguard.flags
又创建了proguard.flags文件，内容如下：
-keep class com.huaqin.runtime.engtools.engfetch {static *;}
}
保留engfentch所有的static方法.测试有效
参考 http://www.cnitblog.com/zouzheng/archive/2011/01/12/72639.html