在 JNA 中传递参数
[英]Passing parameter in JNA
问题描述
此代码填充生成的数据结构 SCANNER_FULL_PLUS_EX，然后调用 function ScanReadFull_PlusEx()。 两者都是由JNAerator生成的，应该创建一些文件，如 Scan_F.bmp 等。
对于 windows 上的64 位 java 10 6 位，字节 [512] 中的文件名无法正确传递给 dll。 大多数时候文件名是null
public short SCANTEST(String fileName) {
StringBuilder BitmapNameF = new StringBuilder();
StringBuilder BitmapNameR = new StringBuilder();
StringBuilder BitmapNameF_IR = new StringBuilder();
StringBuilder BitmapNameR_IR = new StringBuilder();
StringBuilder BitmapNameF_UV = new StringBuilder();
StringBuilder BitmapNameR_UV = new StringBuilder();
SCANNER_FULL_PLUS_EX m_ScanFullPlusEx = new SCANNER_FULL_PLUS_EX();
m_ScanFullPlusEx.Version = 0;
m_ScanFullPlusEx.BrightnessFront = 100;
m_ScanFullPlusEx.ThresholdFront = 100;
m_ScanFullPlusEx.BrightnessRear = 100;
m_ScanFullPlusEx.ThresholdRear = 100;
m_ScanFullPlusEx.BitsPerPixel = 8;
m_ScanFullPlusEx.ScanMode = 2;
m_ScanFullPlusEx.ScanModeIR = 0;
m_ScanFullPlusEx.ScanModeUV = 0;
m_ScanFullPlusEx.dwImageWidth = 0;
m_ScanFullPlusEx.dwImageHeight = 0;
m_ScanFullPlusEx.pImageFront = new NativeLong(0);
m_ScanFullPlusEx.dwImageSizeFront = 0;
m_ScanFullPlusEx.pImageRear = new NativeLong(0);
m_ScanFullPlusEx.dwImageSizeRear = 0;
m_ScanFullPlusEx.pIR_ImageFront = new NativeLong(0);
m_ScanFullPlusEx.dwIR_ImageSizeFront = 0;
m_ScanFullPlusEx.pIR_ImageRear = new NativeLong(0);
m_ScanFullPlusEx.dwIR_ImageSizeRear = 0;
m_ScanFullPlusEx.pUV_ImageFront = new NativeLong(0);
m_ScanFullPlusEx.dwUV_ImageSizeFront = 0;
m_ScanFullPlusEx.pUV_ImageRear = new NativeLong(0);
m_ScanFullPlusEx.dwUV_ImageSizeRear = 0;
BitmapNameF.append(fileName + "F.bmp");
BitmapNameR.append(fileName + "R.bmp");
BitmapNameF_IR.append(fileName + "F_IR.bmp");
BitmapNameR_IR.append(fileName + "R_IR.bmp");
BitmapNameF_UV.append(fileName + "F_UV.bmp");
BitmapNameR_UV.append(fileName + "R_UV.bmp");
m_ScanFullPlusEx.ImageNameRear = Native.toByteArray(BitmapNameR.toString());
m_ScanFullPlusEx.ImageNameFront = Native.toByteArray(BitmapNameF.toString());
m_ScanFullPlusEx.IR_ImageNameFront = Native.toByteArray(BitmapNameF_IR.toString());
m_ScanFullPlusEx.IR_ImageNameRear = Native.toByteArray(BitmapNameR_IR.toString());
m_ScanFullPlusEx.UV_ImageNameFront = Native.toByteArray(BitmapNameF_UV.toString());
m_ScanFullPlusEx.UV_ImageNameRear = Native.toByteArray(BitmapNameR_UV.toString());
// wrap in 512 buffer
byte[] f1 = new byte[512]; for (int i=0; i<m_ScanFullPlusEx.ImageNameRear.length;i++) f1[i]=m_ScanFullPlusEx.ImageNameRear[i]; m_ScanFullPlusEx.ImageNameRear = f1;
byte[] f2 = new byte[512]; for (int i=0; i<m_ScanFullPlusEx.ImageNameFront.length;i++) f2[i]=m_ScanFullPlusEx.ImageNameFront[i]; m_ScanFullPlusEx.ImageNameFront = f2;
byte[] f3 = new byte[512]; for (int i=0; i<m_ScanFullPlusEx.IR_ImageNameFront.length;i++) f3[i]=m_ScanFullPlusEx.IR_ImageNameFront[i]; m_ScanFullPlusEx.IR_ImageNameFront = f3;
byte[] f4 = new byte[512]; for (int i=0; i<m_ScanFullPlusEx.IR_ImageNameRear.length;i++) f4[i]=m_ScanFullPlusEx.IR_ImageNameRear[i]; m_ScanFullPlusEx.IR_ImageNameRear = f4;
byte[] f5 = new byte[512]; for (int i=0; i<m_ScanFullPlusEx.UV_ImageNameFront.length;i++) f5[i]=m_ScanFullPlusEx.UV_ImageNameFront[i]; m_ScanFullPlusEx.UV_ImageNameFront = f5;
byte[] f6 = new byte[512]; for (int i=0; i<m_ScanFullPlusEx.UV_ImageNameRear.length;i++) f6[i]=m_ScanFullPlusEx.UV_ImageNameRear[i]; m_ScanFullPlusEx.UV_ImageNameRear = f6;
short ret = MB2Library.INSTANCE.ScanReadFull_PlusEx(ByteBuffer.wrap(Native.toByteArray(gPort.Global)), m_ScanFullPlusEx, MB2Library.SCAN_OUTPUT_FORMAT_FILE_BMP);
return ret;
}
C header 文件的结构。
typedef struct
{
int Version;
int BrightnessFront;
int ThresholdFront;
int BrightnessRear;
int ThresholdRear;
int BitsPerPixel;
int ScanMode; // Front/Rear/Front-Rear
int ScanModeIR; // ( not yet implemented ) IR Front/Rear/Front-Rear
int ScanModeUV; // ( not yet implemented ) UV Front/Rear/Front-Rear
DWORD dwImageWidth;
DWORD dwImageHeight;
// Front CIS Image
HANDLE pImageFront;
DWORD dwImageSizeFront;
// Rear CIS Image
HANDLE pImageRear;
DWORD dwImageSizeRear;
// Front IR Image
HANDLE pIR_ImageFront;
DWORD dwIR_ImageSizeFront;
// Rear IR Image
HANDLE pIR_ImageRear;
DWORD dwIR_ImageSizeRear;
// Front UV Image
HANDLE pUV_ImageFront;
DWORD dwUV_ImageSizeFront;
// Rear UV Image
HANDLE pUV_ImageRear;
DWORD dwUV_ImageSizeRear;
// images path
TCHAR ImageNameFront[512];
TCHAR ImageNameRear[512];
TCHAR IR_ImageNameFront[512];
TCHAR IR_ImageNameRear[512];
TCHAR UV_ImageNameFront[512];
TCHAR UV_ImageNameRear[512];
} SCANNER_FULL_PLUS_EX;
typedef SCANNER_FULL_PLUS_EX *PSCANNER_FULL_PLUS_EX;
编辑1：
package mb2;
import java.util.StringTokenizer;
import java.util.Arrays;
import java.util.List;
import com.sun.jna.Library;
import com.sun.jna.Native;
import com.sun.jna.NativeLibrary;
import com.sun.jna.NativeLong;
import com.sun.jna.Pointer;
import com.sun.jna.Structure;
import com.sun.jna.ptr.ByReference;
import com.sun.jna.ptr.PointerByReference;
import com.sun.jna.ptr.IntByReference;
import com.sun.jna.ptr.ByteByReference;
import com.sun.jna.ptr.DoubleByReference;
import com.sun.jna.ptr.FloatByReference;
import com.sun.jna.ptr.LongByReference;
import com.sun.jna.ptr.NativeLongByReference;
import com.sun.jna.ptr.ShortByReference;
public class SCANNER_FULL_PLUS_EX extends Structure {
public int Version;
public int BrightnessFront;
public int ThresholdFront;
public int BrightnessRear;
public int ThresholdRear;
public int BitsPerPixel;
/** Front/Rear/Front-Rear */
public int ScanMode;
/** ( not yet implemented ) IR Front/Rear/Front-Rear */
public int ScanModeIR;
/** ( not yet implemented ) UV Front/Rear/Front-Rear */
public int ScanModeUV;
public int dwImageWidth;
public int dwImageHeight;
/**
* Front CIS Image<br>
* C type : HANDLE
*/
public NativeLong pImageFront;
public int dwImageSizeFront;
/**
* Rear CIS Image<br>
* C type : HANDLE
*/
public NativeLong pImageRear;
public int dwImageSizeRear;
/**
* Front IR Image<br>
* C type : HANDLE
*/
public NativeLong pIR_ImageFront;
public int dwIR_ImageSizeFront;
/**
* Rear IR Image<br>
* C type : HANDLE
*/
public NativeLong pIR_ImageRear;
public int dwIR_ImageSizeRear;
/**
* Front UV Image<br>
* C type : HANDLE
*/
public NativeLong pUV_ImageFront;
public int dwUV_ImageSizeFront;
/**
* Rear UV Image<br>
* C type : HANDLE
*/
public NativeLong pUV_ImageRear;
public int dwUV_ImageSizeRear;
/**
* images path<br>
* C type : TCHAR[512]
*/
public byte[] ImageNameFront = new byte[512];
/** C type : TCHAR[512] */
public byte[] ImageNameRear = new byte[512];
/** C type : TCHAR[512] */
public byte[] IR_ImageNameFront = new byte[512];
/** C type : TCHAR[512] */
public byte[] IR_ImageNameRear = new byte[512];
/** C type : TCHAR[512] */
public byte[] UV_ImageNameFront = new byte[512];
/** C type : TCHAR[512] */
public byte[] UV_ImageNameRear = new byte[512];
public SCANNER_FULL_PLUS_EX() {
super();
}
protected List<String> getFieldOrder() {
return Arrays.asList("Version", "BrightnessFront", "ThresholdFront", "BrightnessRear", "ThresholdRear", "BitsPerPixel", "ScanMode", "ScanModeIR", "ScanModeUV", "dwImageWidth", "dwImageHeight", "pImageFront", "dwImageSizeFront", "pImageRear", "dwImageSizeRear", "pIR_ImageFront", "dwIR_ImageSizeFront", "pIR_ImageRear", "dwIR_ImageSizeRear", "pUV_ImageFront", "dwUV_ImageSizeFront", "pUV_ImageRear", "dwUV_ImageSizeRear", "ImageNameFront", "ImageNameRear", "IR_ImageNameFront", "IR_ImageNameRear", "UV_ImageNameFront", "UV_ImageNameRear");
}
public SCANNER_FULL_PLUS_EX(Pointer peer) {
super(peer);
}
public static class ByReference extends SCANNER_FULL_PLUS_EX implements Structure.ByReference {
};
public static class ByValue extends SCANNER_FULL_PLUS_EX implements Structure.ByValue {
};
}
1 个解决方案
解决方案1
0 2020-06-17 17:17:23
欢迎来到字符编码的奇妙世界。
您仅使用带有String参数的Native.toByteArray() 。 这将返回：
与给定字符串等效的以 NUL 结尾的字节缓冲区，使用 getDefaultStringEncoding() 返回的编码。
在字符串和字节 arrays 之间进行转换时，不指定编码通常是一种不好的做法。 在这种情况下，您实际上确实需要默认系统编码，但指定它很有用，并且在此过程中，了解它在做什么。
默认的 Windows 编码是 UTF-16，它使用 16 位来表示字符（C 中的wchar_t ）。 对于 ASCII 字符串，就像您正在使用的字符串一样，这意味着您的字节数组以交替的 0 字节和 8 位字符字节结束。 （请随意检测您的代码和 output Arrays.toString(f1)自己看看这个！）
C 结构使用TCHAR的 arrays 。 这可以是单个字节或两个字节，具体取决于您的编码（将匹配Native.toByteArray() ）。
所以这里的默认编码很好，除了你需要知道那个编码是什么，以便正确调整你的结构。 当您可能需要 512-TCHAR arrays（1024 字节）时，您正在传递 512 字节 arrays。
但是，JNA 结构必须知道它们的总字节大小，并且TCHAR未映射到 JNA 中。 因此，您必须计算出CHAR_WIDTH并将 512 乘以结构中的该值。 （在 JNA 源代码中搜索CHAR_WIDTH以获得大量示例。）
（编辑 1）
感谢您提供 JNA 映射。 通常，当 JNA 映射的函数/结构行为不端时，首先要查看的是类型映射。 在您的情况下，除了上述错误的TCHAR映射到byte之外，您还将HANDLE映射为NativeLong 。 这在 Windows 上不起作用： HANDLE从PointerType扩展，并且指针匹配操作系统位数，64 位 Windows 上的 64 位也是如此。 另一方面，Windows LONG （因此在 Windows 上为NativeLong ）始终是 32 位类型。
总而言之，您需要（至少）以下更改：
将
HANDLE类型更改为 map 为 JNA 的WinNT.HANDLEclass更改
TCHAR字节宽度以匹配字符宽度。 一种方法是将其插入 class 的顶部（或项目中的任何位置，公开，以便访问）：private static final int CHAR_WIDTH = Boolean.getBoolean("w32.ascii")? 1: 2;
然后在您的byte[]声明中，乘以512 * CHAR_WIDTH以获得正确的宽度。
jna传递几个参数
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