Question

jsp运行时出现这个错误，哪里出错了？求大神指教

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: javax.servlet.ServletException: java.lang.NoSuchMethodError: com.db.update(Ljava/lang/String;)I
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:532)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:408)
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)

root cause

javax.servlet.ServletException: java.lang.NoSuchMethodError: com.db.update(Ljava/lang/String;)I
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:855)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:784)
org.apache.jsp.zz2_jsp._jspService(zz2_jsp.java:78)
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:384)
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)

root cause

java.lang.NoSuchMethodError: com.db.update(Ljava/lang/String;)I
org.apache.jsp.zz2_jsp._jspService(zz2_jsp.java:63)
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:384)
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)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.10 logs.

--------------------------------------------------------------------------------

Apache Tomcat/6.0.10
<%@ page language="java" import="java.util.*,com.db" pageEncoding="ISO-8859-1"%>
<%
String name,pass,sql;
name=request.getParameter("a1");
pass=request.getParameter("a2");
sql="insert into stu values('"+name+"','"+pass+"')";
db kk=new db();
int i=kk.update(sql);
if(i!=0)
{
out.print("success");
}
else
{
out.print("failed");
}
%>

Answer 1

java.lang.NoSuchMethodError: com.db.update(Ljava/lang/String;)I
这是参数类型不匹配导致的。
可以去对应的类中是否有这个方法类型，如果没有的话，可以看看是定义的方法不对，还是传递的参数不对。

追问

我大二学生，刚刚接触jsp，你能简单的告诉我应该怎么修改吗

追答

先看一下是不是有update这个方法，传参是不是正确，参数类型对不对