實驗內容：利用Statement演示SQL
實驗要求：
1. =演示用戶登錄功能；
2. 用戶輸入用戶名，如tom；用戶輸入密碼，如123，成功登錄，顯示success!；否則登錄不成功，顯示error!
3. 演示SQL，用戶名輸入：jack ‘ or 1=1 -- ,密碼輸入：345，成功登錄，顯示success!
【貼代碼】
package com;
import java.sql.*;
import java.util.Scanner;
public class Jdbc {
private final String URL="jdbc:mysql://localhost:3306/mon";
private final String USER="root";
private final String PWD="1234";
public void login() {
Connection con = null;
Statement stmt = null;
ResultSet rs = null;
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(URL,USER,PWD);
stmt=con.createStatement();
Scanner input = new Scanner(System.in);
System.out.println("input user:");
String u=input.nextLine();
System.out.println("input pwd:");
String p=input.nextLine();
String sql="select count(*) from login where user='"+u+"' and pwd='"+p+"'";
rs=stmt.executeQuery(sql);
int c=-1;
if(rs.next()) {
c=rs.getInt(1);
}
if(c>0) {
System.out.println("success!");
} else {
System.out.println("error!");
}
} catch(Exception e) {
e.printStackTrace();
} finally {
try {
if(rs!=null) rs.close();
if(stmt!=null) rs.close();
if(con!=null) rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
Jdbc b= new Jdbc();
b.login();
}
}
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