1、先要导入jdbc-mysql包
2、程序框架：
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3、数据库配置文件
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/jdbc_db
username=root
password=1234
4、访问底层数据：
package cn.com.dale.utils;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
public class Utils {
public Connection openConnection(){
Properties pro = new Properties();
try {
pro.load(this.getClass().getClassLoader().getResourceAsStream("DBConfig.properties"));
String driver = pro.getProperty("driver");
String url = pro.getProperty("url");
String username = pro.getProperty("username");
String password = pro.getProperty("password");
Class.forName(driver);
return DriverManager.getConnection(url,username,password);
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public void closeConnection(Connection conn){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
5、javabean：
package cn.com.dale.Bean;
public class User {
private String name;
private String password;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
6、接口：
package cn.com.dale.Dao;
import cn.com.dale.Bean.User;
public interface UserDao {
//denglu
public User login(User user);
//zhuce
public void register(User user);
//jiancha
public boolean check(String name);
}
7、接口实现类：
package cn.com.dale.DaoImpl;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import cn.com.dale.Bean.User;
import cn.com.dale.Dao.UserDao;
import cn.com.dale.utils.Utils;
public class UserDaoImpl implements UserDao{
public void register(User user) {
if(check(user.getName())==false){
System.out.println("该用户名已存在！");
return;
}
String sql = "insert into usertab(username,password) values(?,?)";
Utils utils = new Utils();
Connection conn = utils.openConnection();
try {
PreparedStatement stmt = conn.prepareStatement(sql);
stmt.setString(1,user.getName());
stmt.setString(2, user.getPassword());
stmt.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
utils.closeConnection(conn);
}
}
public User login(User user) {
String sql="select * from usertab where username=? and password=?";
Utils utils = new Utils();
Connection conn = utils.openConnection();
try {
PreparedStatement stmt = conn.prepareStatement(sql);
stmt.setString(1, user.getName());
stmt.setString(2, user.getPassword());
ResultSet rs = stmt.executeQuery();
if(rs.next()){
return user;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
utils.closeConnection(conn);
}
return null;
}
public boolean check(String name) {
String sql = "select * from usertab where username=?";
Utils utils = new Utils();
Connection conn = utils.openConnection();
try {
Pre