这是登陆jsp代码
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="yanzheng.jsp" method="post">
<p><input type="text" name="username"></p>
<p><input type="password" name="password"></p>
<P><input type="submit" value="提交"></P>
</form>
</body>
</html>
验证代码：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" import="com.jdbc.TestDB"%>
<%
String username=request.getParameter("username");
String pwd=request.getParameter("password");
if(TestDB.validate(username,pwd)){
response.sendRedirect("chenggong.jsp");
}else{
out.println("<script>alert('帐号或密码错误');</script>");
}
%>
TestDB.java代码：
package com.jdbc;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class TestDB {
public static boolean validate (String username,String password){
boolean result=false;
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
Connection con = java.sql.DriverManager.getConnection(
"jdbc:mysql://localhost/db", "root", "123456");
Statement stmt = con.createStatement();
ResultSet rst = stmt
.executeQuery("select password from user where username='"+username+"';");
while (rst.next()) {
String passwordFormdb=rst.getString("password");
if(password.equals(passwordFormdb)){
result=true;
}
}
rst.close();
stmt.close();
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}
}
运行tomcat出现错误：
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:
An error occurred at line: 6 in the generated java file
Only a type can be imported. com.jdbc.TestDB resolves to a package
An error occurred at line: 7 in the jsp file: /yanzheng.jsp
TestDB cannot be resolved
4: String username=request.getParameter("username");
5: String pwd=request.getParameter("password");
6:
7: if(TestDB.validate(username,pwd)){
8: response.sendRedirect("chenggong.jsp");
9:
10: }else{
Stacktrace:
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:92)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:423)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:317)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:295)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:282)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:586)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.18 logs.
再刷新错误出现这个
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: org.apache.jasper.JasperException: Unable to load class for JSP
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:156)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
org.apache.jasper.JasperException: Unable to load class for JSP
org.apache.jasper.JspCompilationContext.load(JspCompilationContext.java:620)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:144)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
java.lang.ClassNotFoundException: org.apache.jsp.yanzheng_jsp
java.net.URLClassLoader$1.run(URLClassLoader.java:366)
java.net.URLClassLoader$1.run(URLClassLoader.java:355)
java.security.AccessController.doPrivileged(Native Method)
java.net.URLClassLoader.findClass(URLClassLoader.java:354)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:134)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:66)
org.apache.jasper.JspCompilationContext.load(JspCompilationContext.java:618)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:144)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.18 logs.
------解决思路----------------------
<form action="yanzheng.jsp" method="post"> action ="xxx.action"
先把这个修改了，然后运行，有其他错误在调试吧。
------解决思路----------------------
貌似是在页面没找到那个TestDB类，你好好看看是不是正确导入了