JNA

JNA（Java Native Access ）提供一组Java工具类用于在运行期动态访问系统本地库（native library：如Window的dll）而不需要编写任何Native/JNI代码。开发人员只要在一个Java接口中描述目标native library的函数与结构，JNA将自动实现Java接口到native function的映射。

优点：JNA可以让你像调用一般java方法一样直接调用本地方法。就和直接执行本地方法差不多，而且调用本地方法还不用额外的其他处理或者配置什么的，也不需要多余的引用或者编码，使用很方便。
缺点：JNA是建立在JNI的基础之上的，所以效率会比JNI低。

关键代码

import com.sun.jna.Library;
import com.sun.jna.Memory;
import com.sun.jna.Native;
import com.sun.jna.Pointer;
import com.sun.jna.ptr.IntByReference;
public class LYTest {public interface CLibrary extends Library {CLibrary INSTANCE = (CLibrary)Native.loadLibrary("ly_icparse",CLibrary.class);int Parse(String databuf,IntByReference ickh,IntByReference quantity,IntByReference fc,Pointer cid);int Build(int ickh, int quantity, int fc, String cid, Pointer databuf);}public static void main(String[] args) throws Exception {//用于接收输出的char*Pointer databuf = new Memory(512);  CLibrary.INSTANCE.Build(20133058, 11, 3, "201013000285", databuf);byte[] byteArray = databuf.getByteArray(0, 512);String data = new String(byteArray,"UTF-8");System.out.println("data:"+data);//构建读卡数据String databufstr = "A2131091FFFF8115FFFF201013000285FFFFFFFFFFD27600000400FFFFFFFFFF"+data.substring(64,512);IntByReference ickh = new IntByReference();IntByReference quantity = new IntByReference();IntByReference fc = new IntByReference();Pointer cid = new Memory(12);int result = CLibrary.INSTANCE.Parse(databufstr, ickh, quantity, fc, cid);String cidstr =  new String(cid.getByteArray(0, 12),"UTF-8");System.out.println("ickh:"+ickh.getValue());System.out.println("quantity:"+quantity.getValue());System.out.println("fc:"+fc.getValue());System.out.println("cid:"+cidstr);System.out.println("result:"+result);}
}