java.lang.ClassNotFoundException : SecuGen. FDxSDKPro.jni.JSGFPLib

Question

我想用java构建一个类库。这意味着我想开发一个将在另一个 java 项目中使用的 jar 文件。

在这个类库项目中，我编写了一个名为 FingerMatching 的类。我在 FingerMatching 类中使用 FDxSDKPro.jar 中的 JSGFPLib 类。 JSGFPLib 类位于 SecuGen.FDxSDKPro.jni 包中。

在 FingerMatching 类中，有两个方法。这两个方法的原型(prototype)如下:

 public boolean fingerPrintIndetify(byte[] fingerData, byte[][] fingerEnrollData) 
 boolean fingerprintVerify(byte[] regMin, byte[] regMin1)

构建完这个类项目后，我得到了一个 jar 。让这个 jar 的名称是“FingerMatching.jar”。我已将此 jar 导入到另一个项目中。运行该项目后，我收到此错误。

11-Feb-2018 12:08:15.899 SEVERE [http-nio-8084-exec-77] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [FingerVerification] in context with path [/UFingerEnrollVerify] threw exception [Servlet execution threw an exception] with root cause
 java.lang.ClassNotFoundException: SecuGen.FDxSDKPro.jni.JSGFPLib
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1333)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1167)
    at com.era.Fingerprint.FingerMatching.fingerprintVerify(FingerMatching.java:46)
    at com.era.Fingerprint.FingerMatching.fingerPrintIndetify(FingerMatching.java:31)
    at era.data.FingerPrintVerification.fingerVerfyFromTemplate(FingerPrintVerification.java:102)
    at era.servlet.FingerVerification.doPost(FingerVerification.java:172)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

为什么我会收到此错误？请帮我解决这个错误。

Answer 1

当您的项目在类路径中没有所需的运行时依赖项时，会发生

NoClassDefFoundError。您的 FingerMatching.jar 是否包含 FDxSDKPro.jar 中的所有内容。如果没有，您还必须将 FDxSDKPro.jar 导入到新创建的项目中。