org.apache.jasper.JasperException: An exception occurred processing JSP page /playlistedit/pltagpage.jsp at line 52

type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: An exception occurred processing JSP page /playlistedit/pltagpage.jsp at line 52

49:   </tr>
50:   </form>
51:   <%
52:   for(int i=0;i<pltaglst.size();i++){
53:   PlTagTab tagobj=(PlTagTab)pltaglst.get(i);
54:   %>
55:   <tr>


Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
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)
root cause
java.lang.NullPointerException
org.apache.jsp.playlistedit.pltagpage_jsp._jspService(pltagpage_jsp.java:104)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
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)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.29 logs.

解决办法:
pltaglst集合为空
if判断一下pltaglst集合是否为空，为空就不走环循