第一个编译错误有关代码:CheckUser.java
package test;
import java.sql.*;
import test.TestDBConnection;
public class CheckUser
{
String UserNo,
UserPw,
UserPur; public CheckUser(){
UserNo="";
UserPw="";
UserPur=""; }
public void setUserNo(String UserNo){
this.UserNo=UserNo;
}
public void setUserPw(String UserPw){
this.UserPw=UserPw;
}
public void setUserPur(String UserPur){
this.UserPur=UserPur;
}
public String getUserNo(){
return UserNo;
}
public String getUserPw(){
return UserPw;
}
public String getUserPur(){
return UserPur;
}
public String checkResult(){
.......
.......
}
package test;
import java.sql.*;
import test.TestDBConnection;
public class CheckUser
{
String UserNo,
UserPw,
UserPur; public CheckUser(){
UserNo="";
UserPw="";
UserPur=""; }
public void setUserNo(String UserNo){
this.UserNo=UserNo;
}
public void setUserPw(String UserPw){
this.UserPw=UserPw;
}
public void setUserPur(String UserPur){
this.UserPur=UserPur;
}
public String getUserNo(){
return UserNo;
}
public String getUserPw(){
return UserPw;
}
public String getUserPur(){
return UserPur;
}
public String checkResult(){
.......
.......
}
怎么可能找不到UserNo呢???
<jsp:setProperty name="login" property="UserPw" value="<%=password%>"/>
<jsp:setProperty name="login" property="UserPur" value="<%=logrole%>"/>
</jsp:useBean>
//StudentBean.java
public class StudentBean {
private String name;
private String[] favorite;
public StudentBean() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String[] getFavorite() {
return favorite;
}
public void setFavorite(String[] favorite) {
this.favorite = favorite;
}
}
//UseBeanJsp.jsp<jsp:useBean id="student" scope="request" class="StudentBean" />
<jsp:setProperty name="student" property="name" value="liu"/>
<jsp:setProperty name="student" property="favorite" value="Football"/>
<html>
<head>
<title>
UseBeanJsp
</title>
</head><body bgcolor="#ffffff">
<h1>
Use JavaBeans in JSP
</h1>
<form method="post">
<input type="submit" name="Submit" value="Submit">
<input type="reset" value="Reset">
<hr>student<br>
<br>Enter Your Name:<input type="text" name="name">
<br>Your Name: <jsp:getProperty name="student" property="name" /><br>
<hr>
Select Your Favorite:
<br><input type="checkbox" name="favorite" value="Basketball">Basketball
<br><input type="checkbox" name="favorite" value="Football">Football
<br><input type="checkbox" name="favorite" value="Music">Music
<br><input type="checkbox" name="favorite" value="Reading">Reading
<br><input type="checkbox" name="favorite" value="PC Game">PC Game
<br>Your favorite:
<%
String[] favorite = student.getFavorite();
if (favorite != null) {
for (int i =0; i < favorite.length; i ++) {
out.println(favorite[i]);
}
}
%>
<hr><br>
</form>
</body>
</html>
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:372)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause java.lang.NullPointerException
test.CheckUser.checkResult(CheckUser.java:44)
org.apache.jsp.CheckUser_jsp._jspService(CheckUser_jsp.java:113)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
多谢tom2005(快乐着)第二个编译错误已解决,可是为什么我把bean放在..\WEB-INF\classes下就找不到呢??第一个是怎么回事呢?
String no=getUserNo();
String pw=getUserPw();
String pur=getUserPur();
Connection conn;
Statement stmt;
String sql="select UserNo,UserPw,UserPur from user where UserNo=no"; try{
conn=TestDBConnection.getConnection();
stmt=conn.createStatement();//第44行
ResultSet rs=stmt.executeQuery(sql); stmt.close();
conn.close(); if(rs.next())
{
String PW=rs.getString("UserPw");
String PUR=rs.getString("UserPur");
if(PW==pw&&PUR==pur)
{
return "OK";
}
else if(PW==pw)
return "您的身份选择错误,请重新登录!";
else
return "您输入的密码错误,请重新登录!";
}
else
return "这个帐号不存在,请重新登录!";
}
catch(SQLException e){
System.out.println(e.getMessage());
}
return "SQLException";
}看不出有什么错啊?