CTP API 開發之二 ：制作CTP java版 API

 

目前上期技術CTP系統提供的API版本是C++版本

SWIG是一個能將C/C++接口轉換為其他語言的工具，目前可以支持Python,Java,R等語言。
本文主要介紹Windows 32/64位平台下利用Swig工具將CTP C++接口API轉換為Java可調用的接口。

1、從CTP官網下載最新API包，包中包含32位和64位。API文件包清單：

2、下載安裝Swig軟件：

3、在API文件包中創建thostapi.i 和various.i文件，thostapi.i是一個接口文件，用於告訴swig為哪些類和方法創建接口

various.i是用於將C++接口中的數組參數轉換為java 的Array的工具類

%module(directors="1") thosttraderapi 
%include "various.i"
%apply char **STRING_ARRAY { char *ppInstrumentID[] }
%{ 
#include "ThostFtdcMdApi.h"
#include "ThostFtdcTraderApi.h"
%} 
%feature("director") CThostFtdcMdSpi; 
%include "ThostFtdcUserApiDataType.h"
%include "ThostFtdcUserApiStruct.h" 
%include "ThostFtdcMdApi.h"
%feature("director") CThostFtdcTraderSpi;
%include "ThostFtdcTraderApi.h"

4、生成java接口：

在當前文件夾創建src/ctp文件夾用於放置生成的java文件

..\..\swigwin-2.0.11\swig.exe -c++ -java -package ctp.thosttraderapi -outdir src -o thosttraderapi_wrap.cpp thostapi.i

運行完成之后，可在當前文件夾中看到用於包裝原來C++接口的文件：

 

5、通過C++得到java可調用的動態庫

創建一個C++工程，應用程序類型選擇DLL,將以下文件添加到工程中去:

將dk目錄\Java\jdk1.8.0_111\include下的jni.h和win32文件夾下的jni_md.h, jawt_md.h一共三個文件

拷貝到安裝vs的include目錄底下\Microsoft Visual Studio 12.0\VC\include。

因為thosttraderapi_wrap.cpp文件中包含了<jni.h>,是用於生成Java可調用接口的庫文件。

 將如下8個函數注釋掉，這幾個函數中涉及到將字符串轉換為char類型，有問題：

Java_ctp_thosttraderapi_thosttradeapiJNI_THOST_1FTDC_1VTC_1BankBankToFuture_1get 
Java_ctp_thosttraderapi_thosttradeapiJNI_THOST_1FTDC_1VTC_1BankFutureToBank_1get 
Java_ctp_thosttraderapi_thosttradeapiJNI_THOST_1FTDC_1VTC_1FutureBankToFuture_1get 
Java_ctp_thosttraderapi_thosttradeapiJNI_THOST_1FTDC_1VTC_1FutureFutureToBank_1get 
Java_ctp_thosttraderapi_thosttradeapiJNI_THOST_1FTDC_1FTC_1BankLaunchBankToBroker_1get 
Java_ctp_thosttraderapi_thosttradeapiJNI_THOST_1FTDC_1FTC_1BrokerLaunchBankToBroker_1get 
Java_ctp_thosttraderapi_thosttradeapiJNI_THOST_1FTDC_1FTC_1BankLaunchBrokerToBank_1get 
Java_ctp_thosttraderapi_thosttradeapiJNI_THOST_1FTDC_1FTC_1BrokerLaunchBrokerToBank_1get

之后進行編譯，生成java可調用的動態庫文件thosttraderapi_wrap.dll：

6、創建java項目，將三個動態庫和之前生成的src/ctp包拷貝到項目，並加載動態庫進來：

到此java API制作完成，可以進行java開發了

 附various.i:

/* 
 * char **STRING_ARRAY typemaps. 
 * These typemaps are for C String arrays which are NULL terminated.
 *   char *values[] = { "one", "two", "three", NULL }; // note NULL
 * char ** is mapped to a Java String[].
 *
 * Example usage wrapping:
 *   %apply char **STRING_ARRAY { char **input };
 *   char ** foo(char **input);
 *  
 * Java usage:
 *   String numbers[] = { "one", "two", "three" };
 *   String[] ret = modulename.foo( numbers };
 */
%typemap(jni) char **STRING_ARRAY "jobjectArray"
%typemap(jtype) char **STRING_ARRAY "String[]"
%typemap(jstype) char **STRING_ARRAY "String[]"
%typemap(in) char **STRING_ARRAY (jint size) {
    int i = 0;
    size = JCALL1(GetArrayLength, jenv, $input);
#ifdef __cplusplus
    $1 = new char*[size+1];
#else
    $1 = (char **)calloc(size+1, sizeof(char *));
#endif
    for (i = 0; i<size; i++) {
        jstring j_string = (jstring)JCALL2(GetObjectArrayElement, jenv, $input, i);
        const char *c_string = JCALL2(GetStringUTFChars, jenv, j_string, 0);
#ifdef __cplusplus
        $1[i] = new char [strlen(c_string)+1];
#else
        $1[i] = (char *)calloc(strlen(c_string)+1, sizeof(const char *));
#endif
        strcpy($1[i], c_string);
        JCALL2(ReleaseStringUTFChars, jenv, j_string, c_string);
        JCALL1(DeleteLocalRef, jenv, j_string);
    }
    $1[i] = 0;
}

%typemap(freearg) char **STRING_ARRAY {
    int i;
    for (i=0; i<size$argnum-1; i++)
#ifdef __cplusplus
      delete[] $1[i];
    delete[] $1;
#else
      free($1[i]);
    free($1);
#endif
}

%typemap(out) char **STRING_ARRAY {
    int i;
    int len=0;
    jstring temp_string;
    const jclass clazz = JCALL1(FindClass, jenv, "java/lang/String");

    while ($1[len]) len++;    
    jresult = JCALL3(NewObjectArray, jenv, len, clazz, NULL);
    /* exception checking omitted */

    for (i=0; i<len; i++) {
      temp_string = JCALL1(NewStringUTF, jenv, *result++);
      JCALL3(SetObjectArrayElement, jenv, jresult, i, temp_string);
      JCALL1(DeleteLocalRef, jenv, temp_string);
    }
}

%typemap(javain) char **STRING_ARRAY "$javainput"
%typemap(javaout) char **STRING_ARRAY  {
    return $jnicall;
  }

/* 
 * char **STRING_OUT typemaps. 
 * These are typemaps for returning strings when using a C char ** parameter type.
 * The returned string appears in the 1st element of the passed in Java String array.
 *
 * Example usage wrapping:
 *   void foo(char **string_out);
 *  
 * Java usage:
 *   String stringOutArray[] = { "" };
 *   modulename.foo(stringOutArray);
 *   System.out.println( stringOutArray[0] );
 */
%typemap(jni) char **STRING_OUT "jobjectArray"
%typemap(jtype) char **STRING_OUT "String[]"
%typemap(jstype) char **STRING_OUT "String[]"
%typemap(javain) char **STRING_OUT "$javainput"

%typemap(in) char **STRING_OUT($*1_ltype temp) {
  if (!$input) {
    SWIG_JavaThrowException(jenv, SWIG_JavaNullPointerException, "array null");
    return $null;
  }
  if (JCALL1(GetArrayLength, jenv, $input) == 0) {
    SWIG_JavaThrowException(jenv, SWIG_JavaIndexOutOfBoundsException, "Array must contain at least 1 element");
    return $null;
  }
  $1 = &temp; 
}

%typemap(argout) char **STRING_OUT {
  jstring jnewstring = NULL;
  if($1) {
     jnewstring = JCALL1(NewStringUTF, jenv, *$1);
  }
  JCALL3(SetObjectArrayElement, jenv, $input, 0, jnewstring); 
}

/* 
 * char *BYTE typemaps. 
 * These are input typemaps for mapping a Java byte[] array to a C char array.
 * Note that as a Java array is used and thus passeed by reference, the C routine 
 * can return data to Java via the parameter.
 *
 * Example usage wrapping:
 *   void foo(char *array);
 *  
 * Java usage:
 *   byte b[] = new byte[20];
 *   modulename.foo(b);
 */
%typemap(jni) char *BYTE "jbyteArray"
%typemap(jtype) char *BYTE "byte[]"
%typemap(jstype) char *BYTE "byte[]"
%typemap(in) char *BYTE {
    $1 = (char *) JCALL2(GetByteArrayElements, jenv, $input, 0); 
}

%typemap(argout) char *BYTE {
    JCALL3(ReleaseByteArrayElements, jenv, $input, (jbyte *) $1, 0); 
}

%typemap(javain) char *BYTE "$javainput"

/* Prevent default freearg typemap from being used */
%typemap(freearg) char *BYTE ""