在做项目时候，遇到这个500错误。找了很久，jsp写法也没错误，在本地myeclipse可以运行，在别人的myeclipse不能运行，最后终于解决了，是tomcat的版本问题。

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: /PCManage/controlsecletthenews.jsp(303,12) The function getNid must be used with a prefix when a default namespace is not specifiedorg.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:407)org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:148)org.apache.jasper.compiler.Validator$ValidateVisitor$1FVVisitor.visit(Validator.java:1506)org.apache.jasper.compiler.ELNode$Function.accept(ELNode.java:129)org.apache.jasper.compiler.ELNode$Nodes.visit(ELNode.java:200)org.apache.jasper.compiler.ELNode$Visitor.visit(ELNode.java:242)org.apache.jasper.compiler.ELNode$Root.accept(ELNode.java:56)org.apache.jasper.compiler.ELNode$Nodes.visit(ELNode.java:200)org.apache.jasper.compiler.Validator$ValidateVisitor.validateFunctions(Validator.java:1531)org.apache.jasper.compiler.Validator$ValidateVisitor.checkXmlAttributes(Validator.java:1176)org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:846)org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1530)org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361)org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2411)org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:865)org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1530)org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361)org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2411)org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2417)org.apache.jasper.compiler.Node$Root.accept(Node.java:495)org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361)org.apache.jasper.compiler.Validator.validateExDirectives(Validator.java:1763)org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)org.apache.jasper.compiler.Compiler.compile(Compiler.java:347)org.apache.jasper.compiler.Compiler.compile(Compiler.java:327)org.apache.jasper.compiler.Compiler.compile(Compiler.java:314)org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:592)org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)javax.servlet.http.HttpServlet.service(HttpServlet.java:717)serlvet.SearchNewsServlet.doPost(SearchNewsServlet.java:79)javax.servlet.http.HttpServlet.service(HttpServlet.java:637)javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.29 logs.

原因；是tomcat6.0版本不够高，不支持以下代码这样下，因此不断报错。

解决方法：

（1）我是用tomcat6.0运行的，不断地提示错误代码，但是并没有错的。
报错代码贴出来，但是在我的myeclipse是可以运行： <table class=”table table-hover” style=”margin-top:10px;padding:20px;”>



<tr><td>新闻id</td><td>标题</td><td>类别</td><td>作者</td><td>浏览量</td><td>时间</td><td>照片路径</td><td>内容</td></tr>

<c:forEach items=”${project_vector}” var=”vector” varStatus=”status”>

<tr>

<td><c:out value=”${vector.getNid()}”/></td>

<td><c:out value=”${vector.getNbiaoti()}”/></td>

<td><c:out value=”${vector.getNleixing()}”/></td>

<td><c:out value=”${vector.getNzuozhe()}”/></td>

<td><c:out value=”${vector.getNliulangliang()}”/></td>

<td><c:out value=”${vector.getNdate()}”/></td>

<td><img style=”height:30px;width:30px;background:blue” src=”<%=request.getContextPath() %>${vector.getNphotepath()}” alt=””/></td><!– <c:out value=”${vector.getNphotepath()}”/> –>

<td><c:out value=”${vector.getNtext()}”/></td>



</tr>

</c:forEach>


（2）改用tomcat7.0，成功运行，完美解决了这个问题。