一、查询数据表select com.rupeng.jdbctest1;
import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException;
public class Test2 {
public static void main(String[] args) {
// TODO 自动生成的方法存根
try {
Class.forName("com.jdbc.mysql.Driver");
} catch (ClassNotFoundException e) {
System.err.println("加载jdbc驱动"+e.getMessage());
}
Connection conn=null;
PreparedStatement stmt=null;
ResultSet rs=null;
try {
conn=DriverManager.getConnection("jdbc:mysql://localhost/mystudy1?seUnicode=true&characterEncoding=UTF-8", "root", "root");
stmt=conn.prepareStatement("select * from t_persons");
rs=stmt.executeQuery();
while(rs.next()){
int id=rs.getInt("ID");
String name=rs.getString("name");
int age=rs.getInt("age");
String hobbies=rs.getString("hobbies");
System.out.println("ID:"+id+";"+"姓名:"+name+";"+"年龄:"+age+";"+"hobbies:"+hobbies);
}
} catch (SQLException e) {
// TODO 自动生成的 catch 块
//e.printStackTrace();
System.err.println("链接jdbc不成功"+e.getMessage());
}finally{
}
}
}
二、sql实现登录和漏洞 package com.rupeng.jdbctest1;
import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.Scanner;
public class Test3 {
public static void main(String[] args) {
// TODO 自动生成的方法存
Scanner sc=new Scanner(System.in);
System.out.println("enter name");
String name=sc.nextLine();
System.out.println("enter yourpassword");
String password=sc.nextLine();
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO 自动生成的 catch 块
//e.printStackTrace();
System.out.println("加载jdbc驱动" + e.getMessage());
}
Connection conn=null;
PreparedStatement stmt=null;
ResultSet rs=null;
try {
conn=DriverManager.getConnection("jdbc:mysql://localhost/mystudy1?seUnicode=true&characterEncoding=UTF-8", "root", "root");
//String sql="select count(*) c from t_persons2 where name="+name+" and password"+password;
//System.out.println(sql);
//select count(*) c from t_persons2 where name=zhaohan and password123
//缺少单引号
//stmt=conn.prepareStatement(sql);
String sql="select count(*) c from t_persons2 where name='"+name+"' and password'"+password+"'";
System.out.println(sql);
stmt=conn.prepareStatement("select count(*) c from t_persons2 where name='"+name+"'and password='"+password+"'");
rs=stmt.executeQuery();
rs.next();
int c=rs.getInt("c");
System.out.println(c);
if(c<=0){
System.out.println("失败");
}else{
System.out.println("success");
}
// enter name // admin // enter yourpassword // a' or 'a'='a // select count(*) c from t_persons2 where name='admin' and password'a' or 'a'='a' // 1 // success } catch (SQLException e) { // TODO 自动生成的 catch 块 //e.printStackTrace(); System.out.println("链接失败" + e.getMessage()); } }
}
三、改造漏洞 package com.rupeng.jdbctest1;
import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.Scanner;
public class Test3 {
public static void main(String[] args) {
// TODO 自动生成的方法存
Scanner sc=new Scanner(System.in);
System.out.println("enter name");
String name=sc.nextLine();
System.out.println("enter yourpassword");
String password=sc.nextLine();
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO 自动生成的 catch 块
//e.printStackTrace();
System.out.println("加载jdbc驱动" + e.getMessage());
}
Connection conn=null;
PreparedStatement stmt=null;
ResultSet rs=null;
try {
conn=DriverManager.getConnection("jdbc:mysql://localhost/mystudy1?seUnicode=true&characterEncoding=UTF-8", "root", "root");
//String sql="select count(*) c from t_persons2 where name="+name+" and password"+password;
//System.out.println(sql);
//select count(*) c from t_persons2 where name=zhaohan and password123
//缺少单引号
//stmt=conn.prepareStatement(sql);
//String sql="select count(*) c from t_persons2 where name='"+name+"' and password'"+password+"'";
//System.out.println(sql);
//stmt=conn.prepareStatement("select count(*) c from t_persons2 where name='"+name+"'and password='"+password+"'");
// enter name // admin // enter yourpassword // a' or 'a'='a // select count(*) c from t_persons2 where name='admin' and password'a' or 'a'='a' // 1 // success
String sql="select count(*) c from t_persons2 where name=? and password=?";
stmt=conn.prepareStatement(sql);
stmt.setString(1, name);
stmt.setString(2, password);
rs=stmt.executeQuery();
rs.next();
int c=rs.getInt("c");
System.out.println(c);
if(c<=0){
System.out.println("失败");
}else{
System.out.println("success");
}
// } catch (SQLException e) { // TODO 自动生成的 catch 块 //e.printStackTrace(); System.out.println("链接失败" + e.getMessage()); } }
}
