include .h file into java file in android using jni as source folder of .h file?

Question

  void ProcedureParams_Initialize(ProcedureParams* pVal);
    flag ProcedureParams_IsConstraintValid(const ProcedureParams* val, int* pErrCode);
    flag ProcedureParams_XER_Encode(const ProcedureParams* val, ByteStream* pByteStrm, int* pErrCode, flag bCheckConstraints);
    flag ProcedureParams_XER_Decode(ProcedureParams* pVal, ByteStream* pByteStrm, int* pErrCode);
    flag ProcedureParams_BER_Encode(const ProcedureParams* val, ByteStream* pByteStrm, int* pErrCode, flag bCheckConstraints);
    flag ProcedureParams_BER_Decode(ProcedureParams* pVal, ByteStream* pByteStrm, int* pErrCode);

typedef struct {
    GeneralEvthParams g_params;
    DataParams d_params;
} EvtHandlerParams;

how i can add .h file directly into my .java file. i'm using NDk and .h file inside my jni folder.i want to use the functions of header file . how i can directly use functions in java activity? please help me

how i can add .h file directly into my .java file. i'm using NDk and .h file inside my jni folder.i want to use the functions of header file . how i can directly use functions in java activity? please help me — Deepak
– Deepak, Commented Feb 26, 2014 at 12:00

18446744073709551615 · Accepted Answer · 2014-02-26 12:09:30Z

0

You cannot invoke the C/C++ functions directly. The C implementations of Java native functions all have a very specific set of parameters:

  JNIEXPORT jint JNICALL Java_com_mycompany_MyClassName_myfunc
    (JNIEnv * env, jobject obj, jint code) {
     ...
  }

So you will have to create wrapper functions.

A reasonable approach is to define a class including the Java versions of all your native functions (as either static or instance methods), and invoke them via that class.

To generate C headers from the Java (well, not source but the .class files), you can do:

cd bin/classes
javah com.mycompany.MyClassName com.mycompany.AnotherClassName

edited Feb 26, 2014 at 12:09

answered Feb 26, 2014 at 12:03

18446744073709551615

17.1k4 gold badges102 silver badges135 bronze badges

Sign up to request clarification or add additional context in comments.

19 Comments

Deepak Over a year ago

i have already header file inside my jni folder, bt i have to only use the functions inside that header file? is it possible to call that methods directly?

Deepak Over a year ago

Yaa one more thing can is use structure pointers in .java class? if its possible what are the methods, i want to use because inside c source header file i have structure to pointers methods.

18446744073709551615 Over a year ago

Java cannot call C/C++ functions directly, the only way is to define native functions and call the C/C++ functions from them. Anyway, normal C/C++ functions cannot do anything useful with Java Objects or arrays.

Deepak Over a year ago

then how we can access structure variables of .h file?

18446744073709551615 Over a year ago

You can keep pointers to native structures as Java integers, but freeing them will be a bit schizophrenic. Java VM has no direct access to the C structures of the underlying system.

|

Collectives™ on Stack Overflow

include .h file into java file in android using jni as source folder of .h file?

1 Answer 1

19 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

19 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related