SQL注入攻击演示代码

数据库截图：

package TestJDBC;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

/**
 * sql注入攻击的演示代码
 * @author Administrator
 *
 */
public class CopyOfSQLDemo {

    public static void main(String[] args) {

        CopyOfSQLDemo demo = new CopyOfSQLDemo();
        demo.login("a' or 'a'='a", "a' or 'a'='a");
        //欢迎：zs

    }

    public static Connection getConnection() throws Exception{
        Class.forName("com.mysql.jdbc.Driver");
        String url = "jdbc:mysql://localhost:3306/web08";
        return DriverManager.getConnection(url, "root", "root");
    }

    public void login(String username,String password){
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try{
            conn = getConnection();
            st = conn.createStatement();
            String sql = "select * from user where " +
                    "username='"+username+
                    "'and password='"+password+"'";
            //sql注入攻击演示,等价代码
            //String sql = "select * from user where username='a' or 'a'='a'and password='a' or 'a'='a'";
            rs = st.executeQuery(sql);
            if(rs.next()){
                System.out.println("欢迎："+rs.getString("username"));
            }else {
                System.out.println("用户名或密码错误");
            }
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            try{
                if(rs!=null) rs.close();
                if(st!=null) st.close();
                if(conn!=null) conn.close();
            }catch(Exception e){
                e.printStackTrace();
            }
        }
    }
}