couldn't find native method问题的解决

第一类问题：

问题现象：

E/dalvikvm( 3349): ERROR: couldn't find native method
E/dalvikvm( 3349): Requested: Lcom/orbbec/NativeNI/OrbbecUtils;.CoventDepthTORGB:(Ljava/nio/ByteBuffer;Ljava/nio/ByteBuffer;II)I
W/dalvikvm( 3349): Exception Ljava/lang/NoSuchMethodError; thrown while initializing Lcom/orbbec/NativeNI/OrbbecUtils;
W/dalvikvm( 3349): threadid=13: thread exiting with uncaught exception (group=0x4157c300)
E/AndroidRuntime( 3349): FATAL EXCEPTION: Thread-314
E/AndroidRuntime( 3349): Process: com.orbbec.obcolor, PID: 3349
E/AndroidRuntime( 3349): java.lang.NoSuchMethodError: no static or non-static method "Lcom/orbbec/NativeNI/OrbbecUtils;.CoventDepthTORGB(Ljava/nio/ByteBuffer;Ljava/nio/ByteBuffer;II)I"
E/AndroidRuntime( 3349):     at java.lang.Runtime.nativeLoad(Native Method)
E/AndroidRuntime( 3349):     at java.lang.Runtime.doLoad(Runtime.java:421)
E/AndroidRuntime( 3349):     at java.lang.Runtime.loadLibrary(Runtime.java:362)
E/AndroidRuntime( 3349):     at java.lang.System.loadLibrary(System.java:526)
E/AndroidRuntime( 3349):     at com.orbbec.NativeNI.OrbbecUtils.(OrbbecUtils.java:6)
E/AndroidRuntime( 3349):     at com.orbbec.stream.AndroidCamera.getRGBData(AndroidCamera.java:224)
E/AndroidRuntime( 3349):     at orbbec.com.obcolor.MainActivity$4.run(MainActivity.java:317)
W/ActivityManager(  469):   Force finishing activity com.orbbec.obcolor/orbbec.com.obcolor.MainActivity

 

提示找不到CoventDepthTORGB这个本地方法。

首先在网上找到这个问题的最常见的方法是：

在Android.mk中增加行：LOCAL_PROGUARD_ENABLED := disabled 

 

发生问题时的注册表：

JNINativeMethod jniMethods[] = {
  { "CoventDepthTORGB",             "(Ljava/nio/ByteBuffer;Ljava/nio/ByteBuffer;II)I",    (void*)&Native_CoventDepthTORGB},

  { "DrawDepth",             "([III)I",    (void*)&Native_DrawDepth},
  { "ByteToRGBData",                    "([B[IIII)I",                                         (void*)&Native_ByteToRGBData},
  { "ByteToBGRData",                    "([B[IIII)I",                                         (void*)&Native_ByteToBGRData},
 { "NV21ToRGBA",                       "([BLjava/nio/ByteBuffer;II)I",                                          (void*)&Native_NV21ToRGBA},
  { "NV21ToBGR",                       "([B[III)I",                                          (void*)&Native_NV21ToBGR},
  { "NV21ToMirrorRGBA",                 "([B[III)I",                                          (void*)&Native_NV21ToMirrorRGBA},
  { "YUV422ToRGBA",               "([B[IIIZ)I",                                          (void*)&Native_YUV422ToRGBA},
  { "UserOffset",                      "(Ljava/lang/String;Ljava/nio/ByteBuffer;[SII[FI)I",               (void*)&Native_UserOffset},
  { "DepthOffset",                      "([S[SIII)I",                                          (void*)&Native_DepthOffset},
  { "GetOffsetValue",                 "(Ljava/lang/String;F)F",            (void*)&GetOffsetValue},
  { "BgrToArgb",                 "([I[III)I",            (void*)&Native_BgrToArgb},
  {"IsPro", "()Z", (void*)&Native_IsPro},
  {"ByteToRGBA",                  "(Ljava/nio/ByteBuffer;Ljava/nio/ByteBuffer;III)I",   (void*)&Native_ByteToRGBA},
};

发生问题时的java层本地方法的声明：

public class OrbbecUtils {
   static {
      System.loadLibrary("OrbbecUtils");
        System.loadLibrary("OrbbecUtils_jni");
    }
   
     public native static int CoventFromDepthTORGB(int[] pdepth,int width, int height );
 public native static int ByteToRGBData(byte[] pByteColor,int[] pIntColor, int width, int height ,int sdkVersion);
     public native static int NV21ToMirrorRGBA(byte[] nv21data,int[] rgbdata, int width, int height );
     public native static int NV21ToRGBA(byte[] nv21data,int[] rgbdata, int width, int height );
 public native static int YUV422ToRGBA(byte[] yuvdata,int[] rgbdata, int width, int height, boolean mirror);

     public native static boolean IsPro();
 public native static int DepthOffset(short []src, short []dst, int w, int h, int offset);
 public native static float GetOffsetValue(String serialnumber, float distances);
 public native static int NV21ToBGR(byte[] nv21Byte,int[] bgrData, int width, int height );
     public native static int BgrToArgb(int [] bgr, int []rgb, int w, int h);
     
     public native static int Exit();
}

结果发现在本地方法声明时，没有声明CoventDepthTORGB，所以在注册本地方法与其实现之间的对应关系时，将CoventDepthTORGB去掉即可。

JNINativeMethod jniMethods[] = {
 // { "CoventDepthTORGB",             "(Ljava/nio/ByteBuffer;Ljava/nio/ByteBuffer;II)I",    (void*)&Native_CoventDepthTORGB},

  { "DrawDepth",             "([III)I",    (void*)&Native_DrawDepth},
  { "ByteToRGBData",                    "([B[IIII)I",                                         (void*)&Native_ByteToRGBData},
  { "ByteToBGRData",                    "([B[IIII)I",                                         (void*)&Native_ByteToBGRData},
 { "NV21ToRGBA",                       "([BLjava/nio/ByteBuffer;II)I",                                          (void*)&Native_NV21ToRGBA},
  { "NV21ToBGR",                       "([B[III)I",                                          (void*)&Native_NV21ToBGR},
  { "NV21ToMirrorRGBA",                 "([B[III)I",                                          (void*)&Native_NV21ToMirrorRGBA},
  { "YUV422ToRGBA",               "([B[IIIZ)I",                                          (void*)&Native_YUV422ToRGBA},
  { "UserOffset",                      "(Ljava/lang/String;Ljava/nio/ByteBuffer;[SII[FI)I",               (void*)&Native_UserOffset},
  { "DepthOffset",                      "([S[SIII)I",                                          (void*)&Native_DepthOffset},
  { "GetOffsetValue",                 "(Ljava/lang/String;F)F",            (void*)&GetOffsetValue},
  { "BgrToArgb",                 "([I[III)I",            (void*)&Native_BgrToArgb},
  {"IsPro", "()Z", (void*)&Native_IsPro},
  {"ByteToRGBA",                  "(Ljava/nio/ByteBuffer;Ljava/nio/ByteBuffer;III)I",   (void*)&Native_ByteToRGBA},
};

 

第二类问题：前面不符合，方法声明的签名为：public native static int NV21ToRGBA(byte[] nv21data,int[] rgbdata, int width, int height );

注册时指定的签名为： { "NV21ToRGBA",                       "([BLjava/nio/ByteBuffer;II)I",                                          (void*)&Native_NV21ToRGBA},

 

D/OrbbecUtils( 3613):   pid: 0xffffffff
D/dalvikvm( 3613): Added shared lib /data/app-lib/com.orbbec.obcolor-1/libOrbbecUtils_jni.so 0x41842a00
E/dalvikvm( 3613): ERROR: couldn't find native method
E/dalvikvm( 3613): Requested: Lcom/orbbec/NativeNI/OrbbecUtils;.NV21ToRGBA:([BLjava/nio/ByteBuffer;II)I
E/dalvikvm( 3613): Candidate: Lcom/orbbec/NativeNI/OrbbecUtils;.NV21ToRGBA:([B[III)I
W/dalvikvm( 3613): Exception Ljava/lang/NoSuchMethodError; thrown while initializing Lcom/orbbec/NativeNI/OrbbecUtils;
W/dalvikvm( 3613): threadid=14: thread exiting with uncaught exception (group=0x4157c300)
E/AndroidRuntime( 3613): FATAL EXCEPTION: Thread-327
E/AndroidRuntime( 3613): Process: com.orbbec.obcolor, PID: 3613
E/AndroidRuntime( 3613): java.lang.NoSuchMethodError: no static or non-static method "Lcom/orbbec/NativeNI/OrbbecUtils;.NV21ToRGBA([BLjava/nio/ByteBuffer;II)I"
E/AndroidRuntime( 3613):     at java.lang.Runtime.nativeLoad(Native Method)
E/AndroidRuntime( 3613):     at java.lang.Runtime.doLoad(Runtime.java:421)
E/AndroidRuntime( 3613):     at java.lang.Runtime.loadLibrary(Runtime.java:362)
E/AndroidRuntime( 3613):     at java.lang.System.loadLibrary(System.java:526)
E/AndroidRuntime( 3613):     at com.orbbec.NativeNI.OrbbecUtils.(OrbbecUtils.java:6)
E/AndroidRuntime( 3613):     at com.orbbec.stream.AndroidCamera.getRGBData(AndroidCamera.java:224)
E/AndroidRuntime( 3613):     at orbbec.com.obcolor.MainActivity$4.run(MainActivity.java:317)

修正方法为让签名保持一直即可。

关于签名不一致的另外一个例子：

{"getJointPos", "(ILcom/orbbec/global/SkeletonJoint;Lcom/orbbec/global/Point3D;)I", (void*)jni_getJointPos},
由于Lcom/orbbec/global/SkeletonJoint;Lcom/orbbec/global/Point3D;这两个类型的包名，路径不正确导致。

3，JNI_OnLoad实现中，找不到申明本地方法的类导致。

#define REGISTER_CLASS "com/orbbec/interaction/NativeMethods"

jclass clz = env->FindClass(REGISTER_CLASS);

由于REGISTER_CLASS指定的类的路径不对，导致找不到本地方法。