编辑：问题已解决
我创建了一个新项目并导入了源文件。 （在尝试了太多选项之后，项目配置是错误的。）似乎我混淆了load和loadlibrary函数。 load需要一个包含文件后缀的绝对路径，例如：
static { System.load("c:/windows/system32/jnpout32.dll");}
尝试从Eclipse（Windows 7，Java SE1.7）中的Java调用jnpout32.dll（http://www.hytherion.com/beattidp/comput/pport.htm）时收到错误：
Exception in thread "main" java.lang.UnsatisfiedLinkError: EEGTrigger.ioPort.Out32(SS)V
at EEGTrigger.ioPort.Out32(Native Method)
at EEGTrigger.pPort.setAllDataBits(pPort.java:53)
at EEGTrigger.pPort.<init>(pPort.java:19)
at EEGTrigger.EEGTrigger.main(EEGTrigger.java:11)
dll文件位于System32，src文件夹和C：\ Users [user] \ AppData \ Local（由System.getenv（）指示）
在用户条目下的类路径中，文件也已加载
jnpout32.dll - \[Project]\src\[Project]\
，它在Package Explorer中的Referenced Libraries下可见
这两行都不起作用：
static { System.loadLibrary("jnpout32"); }
static { System.load("c:/windows/system32/jnpout32"); }
（。按java.lang.UnsatisfiedLinkError - JNI中的建议加载）
我已经确认（基于java.lang.UnsatisfiedLinkError）
System.getProperty("java.library.path")
返回system32路径。
java项目的完整代码（我只创作了EEGTrigger类。其余的都是dll。）：
package EEGTrigger;
public class EEGTrigger {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("Starting trigger...");
pPort lpt1 = new pPort();
testProtocol(lpt1);
}
private static void testProtocol(pPort lpt1) {
// TODO Auto-generated method stub
short selectTrigger = 0;
sendPulse(lpt1, selectTrigger);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
selectTrigger = 1;
sendPulse(lpt1, selectTrigger);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
selectTrigger = 2;
sendPulse(lpt1, selectTrigger);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
selectTrigger = 3;
sendPulse(lpt1, selectTrigger);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
selectTrigger = 4;
sendPulse(lpt1, selectTrigger);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
selectTrigger = 0;
sendPulse(lpt1, selectTrigger);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* @param lpt1
*/
public static void sendPulse(pPort lpt1, short selectTrigger) {
short trigger = 0;
short targetTrigger = 255;
short stimulusOnsetAsynchrony = 64;
short trialOnsetTrigger = 32;
short triggerOff = 0;
switch (selectTrigger) {
case 1 : trigger = targetTrigger;
break;
case 2 : trigger = stimulusOnsetAsynchrony;
break;
case 3 : trigger = trialOnsetTrigger;
break;
case 4 : trigger = triggerOff;
break;
default : trigger = triggerOff;
break;
}
lpt1.output(trigger);
try {
Thread.sleep(50); // 50 milliseconds
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
lpt1.output(triggerOff);
}
}
package EEGTrigger;
/* Definitions in the build of jnpout32.dll are: */
/* short _stdcall Inp32(short PortAddress); */
/* void _stdcall Out32(short PortAddress, short data); */
public class ioPort
{
// declare native methods of 'jnpout32.dll'
// output a value to a specified port address
public native void Out32(short PortAddress, short data);
// input a value from a specified port address
public native short Inp32(short PortAddress);
// load 'jnpout32.dll'
static { System.loadLibrary("jnpout32");}
//static { System.load("c:/windows/system32/jnpout32"); }
}
package EEGTrigger;
// ** Derived from information provided on the web by Dr. Kenneth G. Schweller,
// ** ( http://web.bvu.edu/faculty/schweller/ ) and his Mars Rover project page.
public class pPort
{
ioPort pp; // wrapper class for 'Jnpout32.dll'
// with methods:
// int Out32(int port, int value);
// int Inp32(int port);
short portAddress; // address of data port
short currentVal; // current value of port bits
public pPort()
{
pp = new ioPort();
portAddress = (short)0x378; // Hex Address of Data Byte of PC Parallel Port
setAllDataBits((short)0); // initialize port bits to 0
currentVal = 0x00;
}
// wrap ParallelPort output method
public void output(short port, short value)
{
pp.Out32(port, value);
}
// wrap ParallelPort input method
public short input(short port)
{
return pp.Inp32(port);
}
// output to default Data port
public void output(short value)
{
pp.Out32(portAddress, value);
}
// input from default Data port
public short input()
{
return pp.Inp32(portAddress);
}
/**
* set all bits on Data port to zero
**/
public void setAllDataBits(short value)
{
pp.Out32(portAddress, value);
currentVal = value;
}
// For users who prefer dealing with Pin numbers
// Set Pin <pin> to <value>
public void setPin(short pin, short value)
{
if (pin >= 2 && pin <= 9)
// just set the corresponding Data bit to indicted value
setDataBit((short)(pin-2), value);
}
/**
* Set Data Bit at selected index to a value of 1 or 0
* while preserving current values of all other Data bits
**/
void setDataBit(short index, short value)
{
switch(index)
{
case 0:
if (value==0) // Set Data[0] to 0
currentVal = (short) (currentVal & 0xFE);
// aaaa aaaa currentVal
// AND 1111 1110 mask
// =========
// aaaa aaa0 new currentVal
else // Set Data[0] to 1
currentVal = (short) (currentVal | 0x01);
// aaaa aaaa currentVal
// OR 0000 0001 mask
// =========
// aaaa aaa1 new currentVal
break;
case 1:
if (value==0)
currentVal = (short) (currentVal & 0xFD);
// currentVal = aaaa aa0a
else
currentVal = (short) (currentVal | 0x02);
// currentVal = aaaa aa1a
break;
case 2:
if (value==0)
currentVal = (short) (currentVal & 0xFB);
// currentVal = aaaa a0aa
else
currentVal = (short) (currentVal | 0x04);
// currentVal = aaaa a1aa
break;
case 3:
if (value==1)
currentVal = (short) (currentVal & 0xF7);
// currentVal = aaaa 0aaa
else
currentVal = (short) (currentVal | 0x08); // currentVal = aaaa 1aaa
break;
case 4:
if (value==0)
currentVal = (short) (currentVal & 0xEF);
// currentVal = aaa0 aaaa
else
currentVal = (short) (currentVal | 0x10); // currentVal = aaa1 aaaa
break;
case 5:
if (value==0)
currentVal = (short) (currentVal & 0xDF);
// currentVal = aa0a aaaa
else
currentVal = (short) (currentVal | 0x20); // currentVal = aa1a aaaa
break;
case 6:
if (value==0)
currentVal = (short) (currentVal & 0xBF);
// currentVal = a0aa aaaa
else
currentVal = (short) (currentVal | 0x40); // currentVal = a1aa aaaa
break;
case 7:
if (value==0)
currentVal = (short) (currentVal & 0x7F);
// currentVal = 0aaa aaaa
else
currentVal = (short) (currentVal | 0x80); // currentVal = 1aaa aaaa
break;
default:
System.out.println("index must be 0 - 7");
}
pp.Out32(portAddress, currentVal);
}
}
以下问题在这方面没有帮助或不适用：
java.lang.UnsatisfiedLinkError
java.lang.UnsatisfiedLinkError
java.lang.UnsatisfiedLinkError
java.lang.UnsatisfiedLinkError
java.lang.UnsatisfiedLinkError in Linux
Java.lang.UnsatisfiedLinkError in eclipse
答案 0 :(得分：0)
您没有提供有关您可能获得UnsatisfiedLinkError的原因的详细信息。尝试附加完整的堆栈跟踪。
只要在JVM通过java -Djava.library.path =“％WINDIR％/ system32 /”启动时设置java.library.path，System.loadLibrary（“jnpout32”）就是正确的
如果要使用System.load，则应该执行类似System.load（“c：/ windows / system32 /”+ System.mapLibraryName（“jnpout32”））的操作，以生成本机库名称和扩展名。< / p>
如果您正确使用它们并且两者都继续失败，那么您的错误就像缺少的依赖库一样。