SWIG Basic using <1>

为了要开发android中间层,是需要费一点时间去摸索的,接下来几篇将介绍NDK使用c++开发入门的步骤:

由于NDK最好是在linux系统下,所以以后全部是在linux下进行的.

这一节介绍如何将cpp转换成java

<1> : 程序很简单,用vim全部编写,文件组成democcp.cpp,democpp.cpp,democpp.h

democcp.cpp是主文件,仅用于测试之用,不需要转换成java.

#include<iostream>
#include"democpp.h"
using namespace std;
int main()
{    int num=0;
    num=addsum(11,22);
    cout<<"sum : "<<num<<endl;
    return 0;
}

democpp.cpp : 具体实现:

#include "democpp.h"
int addsum(int x,int y){
    return x+y;
}

democpp.h : 具体实现:

#ifndef DEMO_CPP_HEADER_H_

#define DEMO_CPP_HEADER_H_



#ifdef __cplusplus

    extern "C"{

#endif



int addsum(int x,int y);



#ifdef __cplusplus

}

#endif

#endif

<2> : 为了不至于上面程序出错,我还是写了一个makefile文件:

democcp:democcp.o democpp.o
    g++ democcp.o democpp.o -o democcp
democcp.o:democcp.cpp democpp.cpp democpp.h
    g++ -c democcp.cpp -o democcp.o
democpp.o:democpp.cpp democpp.h
    g++ -c democpp.cpp -o democpp.o

<3> : 终端中make,然后./democcp后,输出结果33,说明上面程序全部没有写错.

<4> : 那么如何使用swig这个工具了,要使用这个工具,还需要编写*.i的脚本,这个脚本是swig需要的,就像makefile,make指令就直接执行makefile里面的脚本就可以了,

swig也是差不多.

%module democpp
%{
#include "democpp.h"
%}
%include "democpp.h"

swig -c++ -java -package com.test -outdir ./ -I ./democcp.i

上面的格式如下:
swig(转换器) -c++(语言) -java(目的语言) -package  com.test(这个在java中,如果要使用生成java的文件,需要将java放到com.test,不然会提示包位置有问题) -outdir(指向输出路径) ./(我这里是当前路径,如果是同级另外一个文件夹include中,可以改为../include) -I(要求*.i文件脚本) ./democcp.i(i脚本文件的位置,这里是当前位置处)

在终端里面运行上面命令行后,将会生成3个文件:democcp_wrap.cxx,democpp.java(这个文件相当于democcp.cpp对应的,但是意义完全不一样),democppJNI.java(这个文件相当于democcp.h文件).

democppJNI.java :

/* ----------------------------------------------------------------------------
 * This file was automatically generated by SWIG (http://www.swig.org).
 * Version 2.0.4
 *
 * Do not make changes to this file unless you know what you are doing--modify
 * the SWIG interface file instead.
 * ----------------------------------------------------------------------------- */

package com.democpp;

public class democppJNI {
  public final static native int addsum(int jarg1, int jarg2);
}

democpp.java :

/* ----------------------------------------------------------------------------

 * This file was automatically generated by SWIG (http://www.swig.org).

 * Version 2.0.4

 *

 * Do not make changes to this file unless you know what you are doing--modify

 * the SWIG interface file instead.

 * ----------------------------------------------------------------------------- */



package com.democpp;



public class democpp {

  public static int addsum(int x, int y) {

    return democppJNI.addsum(x, y);

  }



}

democcp_wrap.cxx :

/* ----------------------------------------------------------------------------
 * This file was automatically generated by SWIG (http://www.swig.org).
 * Version 2.0.4
 * 
 * This file is not intended to be easily readable and contains a number of 
 * coding conventions designed to improve portability and efficiency. Do not make
 * changes to this file unless you know what you are doing--modify the SWIG 
 * interface file instead. 
 * ----------------------------------------------------------------------------- */

#define SWIGJAVA


#ifdef __cplusplus
/* SwigValueWrapper is described in swig.swg */
template<typename T> class SwigValueWrapper {
  struct SwigMovePointer {
    T *ptr;
    SwigMovePointer(T *p) : ptr(p) { }
    ~SwigMovePointer() { delete ptr; }
    SwigMovePointer& operator=(SwigMovePointer& rhs) { T* oldptr = ptr; ptr = 0; delete oldptr; ptr = rhs.ptr; rhs.ptr = 0; return *this; }
  } pointer;
  SwigValueWrapper& operator=(const SwigValueWrapper<T>& rhs);
  SwigValueWrapper(const SwigValueWrapper<T>& rhs);
public:
  SwigValueWrapper() : pointer(0) { }
  SwigValueWrapper& operator=(const T& t) { SwigMovePointer tmp(new T(t)); pointer = tmp; return *this; }
  operator T&() const { return *pointer.ptr; }
  T *operator&() { return pointer.ptr; }
};

template <typename T> T SwigValueInit() {
  return T();
}
#endif

/* -----------------------------------------------------------------------------
 *  This section contains generic SWIG labels for method/variable
 *  declarations/attributes, and other compiler dependent labels.
 * ----------------------------------------------------------------------------- */

/* template workaround for compilers that cannot correctly implement the C++ standard */
#ifndef SWIGTEMPLATEDISAMBIGUATOR
# if defined(__SUNPRO_CC) && (__SUNPRO_CC <= 0x560)
#  define SWIGTEMPLATEDISAMBIGUATOR template
# elif defined(__HP_aCC)
/* Needed even with `aCC -AA' when `aCC -V' reports HP ANSI C++ B3910B A.03.55 */
/* If we find a maximum version that requires this, the test would be __HP_aCC <= 35500 for A.03.55 */
#  define SWIGTEMPLATEDISAMBIGUATOR template
# else
#  define SWIGTEMPLATEDISAMBIGUATOR
# endif
#endif

/* inline attribute */
#ifndef SWIGINLINE
# if defined(__cplusplus) || (defined(__GNUC__) && !defined(__STRICT_ANSI__))
#   define SWIGINLINE inline
# else
#   define SWIGINLINE
# endif
#endif

/* attribute recognised by some compilers to avoid 'unused' warnings */
#ifndef SWIGUNUSED
# if defined(__GNUC__)
#   if !(defined(__cplusplus)) || (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4))
#     define SWIGUNUSED __attribute__ ((__unused__)) 
#   else
#     define SWIGUNUSED
#   endif
# elif defined(__ICC)
#   define SWIGUNUSED __attribute__ ((__unused__)) 
# else
#   define SWIGUNUSED 
# endif
#endif

#ifndef SWIG_MSC_UNSUPPRESS_4505
# if defined(_MSC_VER)
#   pragma warning(disable : 4505) /* unreferenced local function has been removed */
# endif 
#endif

#ifndef SWIGUNUSEDPARM
# ifdef __cplusplus
#   define SWIGUNUSEDPARM(p)
# else
#   define SWIGUNUSEDPARM(p) p SWIGUNUSED 
# endif
#endif

/* internal SWIG method */
#ifndef SWIGINTERN
# define SWIGINTERN static SWIGUNUSED
#endif

/* internal inline SWIG method */
#ifndef SWIGINTERNINLINE
# define SWIGINTERNINLINE SWIGINTERN SWIGINLINE
#endif

/* exporting methods */
#if (__GNUC__ >= 4) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
#  ifndef GCC_HASCLASSVISIBILITY
#    define GCC_HASCLASSVISIBILITY
#  endif
#endif

#ifndef SWIGEXPORT
# if defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
#   if defined(STATIC_LINKED)
#     define SWIGEXPORT
#   else
#     define SWIGEXPORT __declspec(dllexport)
#   endif
# else
#   if defined(__GNUC__) && defined(GCC_HASCLASSVISIBILITY)
#     define SWIGEXPORT __attribute__ ((visibility("default")))
#   else
#     define SWIGEXPORT
#   endif
# endif
#endif

/* calling conventions for Windows */
#ifndef SWIGSTDCALL
# if defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
#   define SWIGSTDCALL __stdcall
# else
#   define SWIGSTDCALL
# endif 
#endif

/* Deal with Microsoft's attempt at deprecating C standard runtime functions */
#if !defined(SWIG_NO_CRT_SECURE_NO_DEPRECATE) && defined(_MSC_VER) && !defined(_CRT_SECURE_NO_DEPRECATE)
# define _CRT_SECURE_NO_DEPRECATE
#endif

/* Deal with Microsoft's attempt at deprecating methods in the standard C++ library */
#if !defined(SWIG_NO_SCL_SECURE_NO_DEPRECATE) && defined(_MSC_VER) && !defined(_SCL_SECURE_NO_DEPRECATE)
# define _SCL_SECURE_NO_DEPRECATE
#endif



/* Fix for jlong on some versions of gcc on Windows */
#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
  typedef long long __int64;
#endif

/* Fix for jlong on 64-bit x86 Solaris */
#if defined(__x86_64)
# ifdef _LP64
#   undef _LP64
# endif
#endif

#include <jni.h>
#include <stdlib.h>
#include <string.h>


/* Support for throwing Java exceptions */
typedef enum {
  SWIG_JavaOutOfMemoryError = 1, 
  SWIG_JavaIOException, 
  SWIG_JavaRuntimeException, 
  SWIG_JavaIndexOutOfBoundsException,
  SWIG_JavaArithmeticException,
  SWIG_JavaIllegalArgumentException,
  SWIG_JavaNullPointerException,
  SWIG_JavaDirectorPureVirtual,
  SWIG_JavaUnknownError
} SWIG_JavaExceptionCodes;

typedef struct {
  SWIG_JavaExceptionCodes code;
  const char *java_exception;
} SWIG_JavaExceptions_t;


static void SWIGUNUSED SWIG_JavaThrowException(JNIEnv *jenv, SWIG_JavaExceptionCodes code, const char *msg) {
  jclass excep;
  static const SWIG_JavaExceptions_t java_exceptions[] = {
    { SWIG_JavaOutOfMemoryError, "java/lang/OutOfMemoryError" },
    { SWIG_JavaIOException, "java/io/IOException" },
    { SWIG_JavaRuntimeException, "java/lang/RuntimeException" },
    { SWIG_JavaIndexOutOfBoundsException, "java/lang/IndexOutOfBoundsException" },
    { SWIG_JavaArithmeticException, "java/lang/ArithmeticException" },
    { SWIG_JavaIllegalArgumentException, "java/lang/IllegalArgumentException" },
    { SWIG_JavaNullPointerException, "java/lang/NullPointerException" },
    { SWIG_JavaDirectorPureVirtual, "java/lang/RuntimeException" },
    { SWIG_JavaUnknownError,  "java/lang/UnknownError" },
    { (SWIG_JavaExceptionCodes)0,  "java/lang/UnknownError" }
  };
  const SWIG_JavaExceptions_t *except_ptr = java_exceptions;

  while (except_ptr->code != code && except_ptr->code)
    except_ptr++;

  jenv->ExceptionClear();
  excep = jenv->FindClass(except_ptr->java_exception);
  if (excep)
    jenv->ThrowNew(excep, msg);
}


/* Contract support */

#define SWIG_contract_assert(nullreturn, expr, msg) if (!(expr)) {SWIG_JavaThrowException(jenv, SWIG_JavaIllegalArgumentException, msg); return nullreturn; } else


#include "democpp.h"


#ifdef __cplusplus
extern "C" {
#endif

SWIGEXPORT jint JNICALL Java_com_democpp_democppJNI_addsum(JNIEnv *jenv, jclass jcls, jint jarg1, jint jarg2) {
  jint jresult = 0 ;
  int arg1 ;
  int arg2 ;
  int result;
  
  (void)jenv;
  (void)jcls;
  arg1 = (int)jarg1; 
  arg2 = (int)jarg2; 
  result = (int)addsum(arg1,arg2);
  jresult = (jint)result; 
  return jresult;
}


#ifdef __cplusplus
}
#endif

 

ok...