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JavaBean必须用包么?
摘要: JavaBean必须用包么?
我把JavaBean编译好的.class文件放在Tomcat的classes下,我发现在使用package的时候可以,不加package的时候就出错,为什么?
不是加包的问题,是需要知道class的路径
那如果不想用包,直接放在classes下面,怎么声明路径?
它默认的路径不就是classes么?
那不用包就会出错,怎么办?
好像要有虚拟机
编译时,先把.加上,表示当前目录,比如:
javac -classpath c:/classes;.;c:/archives/archive.jar
不是吧是编译过了,在JSP页面用到的JavaBean,第一个页面有个表单,提交之后,出错了
错误提示如下,各位帮我看看
HTTP Status 500 -
--------------------------------------------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: Unable to compile class for JSP
No Java compiler was found to compile the generated source for the JSP.
This can usually be solved by copying manually $JAVA_HOME/lib/tools.jar from the JDK
to the common/lib directory of the Tomcat server, followed by a Tomcat restart.
If using an alternate Java compiler, please check its installation and access path.
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:128)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:351)
org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:413)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:453)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:437)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:555)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:291)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:301)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:248)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
不是必须的
study
好象从Servlet2.3规范后必须用包,用包是一个好习惯,还是用吧
tomcat5开始,好像必须用包
用包可以保证不出错,
不用包不能保证没有错.