在jsp中如何调用.class

Question

<%@ page import="包"%>

Answer 1

util.PageDisplay display=new util.PageDisplay();
                   display.init(request,currentPage,10,sql);
   display.setOtherUrl(otherurl);
   String list= display.programlist();
   out.print(list);

Answer 2

<jsp:useBean id="RegisterBean" scope="page" class="Opendb.DataBasebean" />
<%RegisterBean.Setpathstr(First, Next,Last);//调用bean的方法%>

Answer 3

应该把.class放在那里才可以用jsp:useBean 调用？
我把.class放在跟目录下的class目录下不行

Answer 4

放在--该JSP目录/WEB-INF/classes下

Answer 5

错误信息如下:HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: Unable to compile class for JSPAn error occurred at line: 10 in the jsp file: /test.jspGenerated servlet error:
    [javac] Compiling 1 source fileD:\tomcat\work\Standalone\localhost\_\test_jsp.java:7: cannot resolve symbol
symbol: class counter  
import counter;
^
D:\tomcat\work\Standalone\localhost\_\test_jsp.java:53: cannot resolve symbol
symbol  : class counter  
location: class org.apache.jsp.test_jsp
      counter counter = null;
      ^An error occurred at line: 10 in the jsp file: /test.jspGenerated servlet error:
D:\tomcat\work\Standalone\localhost\_\test_jsp.java:55: cannot resolve symbol
symbol  : class counter  
location: class org.apache.jsp.test_jsp
        counter = (counter) pageContext.getAttribute("counter", PageContext.REQUEST_SCOPE);
                   ^An error occurred at line: 10 in the jsp file: /test.jspGenerated servlet error:
D:\tomcat\work\Standalone\localhost\_\test_jsp.java:58: cannot resolve symbol
symbol  : class counter  
location: class org.apache.jsp.test_jsp
            counter = (counter) java.beans.Beans.instantiate(this.getClass().getClassLoader(), "counter");
                       ^
4 errors
at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:130)
at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:293)
at org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:353)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:370)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:473)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:190)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2416)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:601)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)
at java.lang.Thread.run(Thread.java:479)--------------------------------------------------------------------------------Apache Tomcat/4.1.27

Answer 6

<jsp:useBean id="KeepBean" scope="page" class="bean.Opendb"/>
KeepBean是页面随意定义的名字， page是bean的应用范围，bean.opendb中，bean是包名，opendb是.class文件的名字。opendb.class放的位置是：web-inf/classes/bean/opendb.class

Answer 7

请你用jbuilder 开发jsp 他会为你组织好目录。