我正在尝试开发一个受PHP程序启发的JSP程序，但它的运行方式不同。这其中可能存在什么错误？
这是PHP版本
<?php
$hostname_localhost ="localhost";
$database_localhost ="test";
$username_localhost ="root";
$password_localhost ="";
$localhost = mysql_connect($hostname_localhost,$username_localhost,$password_localhost)
or
trigger_error(mysql_error(),E_USER_ERROR);
mysql_select_db($database_localhost, $localhost);
$username = $_POST['username'];
$password = $_POST['password'];
$query_search = "select * from salesperson where username = '".$username."'AND password = '".$password. "'";
$query_exec = mysql_query($query_search) or die(mysql_error());
$rows = mysql_num_rows($query_exec);
//echo $rows;
if($rows == 0)
{
echo "No Such User Found";
}
else {
echo "User Found";
}
?>
这是 JSP 版本
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="java.sql.*" %>
<% Class.forName("com.mysql.jdbc.Driver"); %>
<%
Connection connection = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/test", "root", "");
String username = request.getParameter("username");
String password = request.getParameter("password");
Statement statement = connection.createStatement() ;
String resultset1 = "select * from test.salesperson WHERE username = '"+ username+"' AND password = '"+password+"' ;";
ResultSet resultSet = statement.executeQuery(resultset1);
if(resultset1.equals(null))
{
out.print("No Such User Found");
}
else
{
out.print("User Found");
}
%>
该程序是为安卓登录客户端编写的，但使用 JSP 无法正常工作。
替换
if(resultset1.equals(null))
{
out.print("No Such User Found");
}
else
{
out.print("User Found");
}
跟
resultset1.next();
int rowCount = resultset1.getInt(1);
if(rowCount < 1)
{
out.print("No Such User Found");
else
{
out.print("User Found");
}
看看它是否有效。