JAVA调用DLL的两种方法-ZPL中文打印（作者不详，如有冒犯，请联系我）

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JAVA调用DLL的两种方法

(2008-03-05 17:24:48)

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标签：

it

问题描述:

方法一,使用JNI:

public class TestNative
{
private native static int Max(int a,intb);

private native static StringgetStr();

public static voidmain(String[] args)
{
System.out.println(Max(2,100));
System.out.println(getStr());
}
static
{
System.loadLibrary("VCdll");
}
}

#include "TestNative.h"
#include "stdlib.h"
#include "string.h"
#include "windows.h"

char* jstringToWindows( JNIEnv *env, jstring jstr );
jstring WindowsTojstring( JNIEnv* env, char* str );

JNIEXPORT jint JNICALL Java_TestNative_Max
(JNIEnv * a, jclass b, jint x, jint y)
{

typedef int (CALLBACK*LPFNDLLFUNC1)(char*,char*,char*,int,int,int,int,int,char*);
LPFNDLLFUNC1 fun;
HINSTANCE hDLL=::LoadLibrary("Fnthex32.dll");
fun=(LPFNDLLFUNC1)GetProcAddress(hDLL,"GETFONTHEX");

FreeLibrary(hDLL);

//return x > y ? x : y;

return 123;
}

JNIEXPORT jstring JNICALL Java_TestNative_getStr
(JNIEnv * a, jclass b)
{
char * Buf_Return;
Buf_Return = (char*)malloc(1024);
Buf_Return = "顶你个肺";
jstring str = WindowsTojstring(a,Buf_Return);

return str;
}

char* jstringToWindows( JNIEnv *env, jstringjstr )
{
int length =(env)->GetStringLength(jstr);
const jchar* jcstr =(env)->GetStringChars(jstr,0);
char* rtn = (char*)malloc( length*2+1 );
int size = 0;
size = WideCharToMultiByte( CP_ACP, 0,(LPCWSTR)jcstr, length, rtn,(length*2+1), NULL, NULL );
if( size <= 0 )
returnNULL;
(env)->ReleaseStringChars(jstr, jcstr);
rtn[size] = 0;
return rtn;
}

jstring WindowsTojstring( JNIEnv* env, char* str )
{
jstring rtn = 0;
int slen = strlen(str);
unsigned short * buffer = 0;
if( slen == 0 )
    rtn =(env)->NewStringUTF(str);
else
{
    int length =MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, NULL, 0 );
    buffer =(unsigned short *)malloc( length*2 + 1 );
    if(MultiByteToWideChar( CP_ACP, 0, (LPCSTR)str, slen, (LPWSTR)buffer,length ) >0 )
     rtn = (env)->NewString( (jchar*)buffer, length);
}
if( buffer )
free( buffer );
return rtn;
}

方法二,使用JNative:

importjava.io.File;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.io.InputStream;

importorg.xvolks.jnative.JNative;
importorg.xvolks.jnative.Type;
import org.xvolks.jnative.exceptions.NativeException;
import  org.xvolks.jnative.pointers.Pointer;
import  org.xvolks.jnative.pointers.memory.*;
public class TestJNative
{
public static void main(String arsp[]) throwsException
{
  JNative n = newJNative("Fnthex32.dll","GETFONTHEX");
  n.setRetVal(Type.INT);

  n.setParameter(0,Type.STRING,"中文");

  n.setParameter(1,Type.STRING,"宋体");


  n.setParameter(2,Type.INT,"0");
  n.setParameter(3,Type.INT,"14");
  n.setParameter(4,Type.INT,"0");
  n.setParameter(5,Type.INT,"1");
  n.setParameter(6,Type.INT,"0");
  Pointer p2= new  Pointer( new HeapMemoryBlock(22*1024));
  p2.setMemory(newbyte[21*1024]);
  n.setParameter(7,p2);



  n.invoke();
  System.out.println(p2.getAsString());
}
}