Jsp中调用DLL(使用JNI)

    技术2022-05-11  70

    jsp调用jni方法

    注:本文介绍Jsp中调用Dll动态链接库文件的方法,摘编自 炼狱的专栏 我的环境: -------- 1. java编译器:eclipse 3.0.2 2. web服务器: tomcat 4.1.24 3. C编译器: VC6.0 4. 操作系统: win2k 5. java源文件目录: d:/study/src 6. java编译后的class文件目录: d:/study/bin 7. tomcat目录: d:/tomcat41 1.编写java文件: //Util.java package com.jni; public class Util {     public native static int add( int x, int y );          static     {         System.loadLibrary( "Util" );     } } 编译这个文件,生成Util.class文件. 2.生成对应的头文件: 打开一个dos窗口,进入存放class文件的目录: d:/>cd d:/study/bin d:/study/bin/>javah com.jni.Util 这样,会在d:/study/bin目录下生成com_jni_Util.h文件. 3. 编写c文件: 在VC6.0中:File->New->Projects->Win32 Dynamic-link Library,Project name 为Util, 创建一个empty DLL project. 把2所生成的com_jni_Util.h文件和C:/j2sdk1.4.2/include目录下的jni.h, C:/j2sdk1.4.2/include/win32目录下的jni_md.h复制到Util工程目录下. (C:/j2sdk1.4.2为我的jsdk的安装路径). 在Util工程中创建一个c源文件,名为Util.c. //Util.c #include "com_jni_Util.h" JNIEXPORT jint JNICALL Java_com_jni_Util_add (JNIEnv *env, jclass jc, jint x, jint y) {     return x+y; } 4. 生成Util.dll: 编译3中的Util.c文件后,会生成Util.dll文件. 5. 生成jar包: 把Util.class文件打成jar包,名为myutil.jar. 6. 编写jsp文件: //test.jsp <%@ page import="com.jni.Util" %> <html> <head></head> <body> <h3>5+7=<%=Util.add( 5, 7 )%></h3> </body> </html> 7. 把myutil.jar包复制到d:/tomcat41/common/lib目录下;    把Util.dll文件复制到d:/tomcat41/bin目录下(也可以是环境变量path的所设定的任何一个目录下);    把test.jsp复制到d:/tomcat41/webapp/test目录下. 8. 启动tomcat. 9. 在ie中输入: http://localhost:8080/test/test.jsp.    如果你能看到: 5+7=12 就成功了. ================================================ 以下为网友回复: #  javalover 发表于2006-12-01 17:57:00  IP: 222.66.100.* 这篇文章太好,我现在有了一个已经生成好的dll文件。在本地调用都没有问题,但是我想在jsp页面中来获得dll文件执行的结果。我现在应该怎么做哪? 我按照你讲的来做,把.class打包,放在tomacat的lib下,dll放在bin下。但是出现了一下的问题 2006-12-1 17:53:26 org.apache.jasper.compiler.Compiler generateClass 严重: Error compiling file: /C:/Tomcat 5.0/work/Catalina/localhost/test//org/apache/jsp/sysinfo_jsp.java [javac] Compiling 1 source file C:/Tomcat 5.0/work/Catalina/localhost/test/org/apache/jsp/sysinfo_jsp.java:57: cannot resolve symbol symbol : class PerfInfoReader location: class org.apache.jsp.sysinfo_jsp PerfInfoReader test = new PerfInfoReader(); ^ C:/Tomcat 5.0/work/Catalina/localhost/test/org/apache/jsp/sysinfo_jsp.java:57: cannot resolve symbol symbol : class PerfInfoReader location: class org.apache.jsp.sysinfo_jsp PerfInfoReader test = new PerfInfoReader(); ^ C:/Tomcat 5.0/work/Catalina/localhost/test/org/apache/jsp/sysinfo_jsp.java:58: cannot resolve symbol symbol : variable PerfInfoReader location: class org.apache.jsp.sysinfo_jsp double o = test.getPerfInfo(PerfInfoReader.CPUUSAGE); ^ 3 errors 能告诉我如何做吗?我现在有了dll文件,也可以在本地来调用。如何在jsp中调用哪。   #   javalover 发表于2006-12-02 21:22:00  IP: 222.66.100.* 我测试了一下: 在tomacat下可以正常的调用JNI,在JBOSS下就不可以了, 有没有人知道在JBOSS下如何解决这个问题啊, 21:20:33,531 ERROR [Engine] StandardWrapperValve[jsp]: Servlet.service() for servlet jsp threw exception java.lang.UnsatisfiedLinkError: getPerfInfo at com.star.sam.sysmonitor.sysperfmonitor.PerfInfoReader.getPerfInfo(Native Method) at com.star.sam.sysmonitor.sysperfmonitor.SysPerformaceSampling.getCPU(SysPerformaceSampling.java:22) at com.star.sam.system.SystemUtil.getCurrentCPU(SystemUtil.java:61) at org.apache.jsp.sammas.sysinfo_jsp._jspService(sysinfo_jsp.java:234) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94) at javax.servlet.http.HttpServlet.service(HttpServlet.java:810) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236) at javax.servlet.http.HttpServlet.service(HttpServlet.java:810) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:75) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214) at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520) at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152) at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104) at org.jboss.web.tomcat.security.CustomPrincipalValve.invoke(CustomPrincipalValve.java:66) at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:162) at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137) at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118) at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929) at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705) at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684) at java.lang.Thread.run(Thread.java:534)

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