怎么改错
虫字 2015-09-01 08:15:34 type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:541)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:435)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
edu.abc.filter.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:121)
root cause
java.lang.NullPointerException
edu.abc.service.CategoryService.listAll(CategoryService.java:122)
org.apache.jsp.index_jsp._jspService(index_jsp.java:87)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
edu.abc.filter.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:121)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.13 logs.
--------------------------------------------------------------------------------
Apache Tomcat/6.0.13
是这段代码错了么!!!!!!
public List<Category> listAll() throws Exception{
Connection connection = null;
List<Category> categoryList=null;
try {
connection = DataBase.getConn();
categoryDaoImpl.setConnection(connection);
categoryList= categoryDaoImpl.listAll();
System.out.println(categoryList.size());
} catch (Exception e) {
e.printStackTrace();
throw e;
}finally{
DataBase.releaseConnection(connection);
}
return categoryList;
}