JDBC 联接 mysql数据库

下面和大家分享一下简单的连接本地数据库的代码：
这是连接DBUtil的代码：

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


public class DBUtil {
    private static final String URL = "jdbc:mysql://127.0.0.1:3306/findstranger";
    private static final String USER = "root";
    private static final String PASSWORD = "quzhiyu";
    private static Connection conn = null;

    static{
        try {
            //1.º”‘ÿ«˝∂Ø≥ÖÚ
            Class.forName("com.mysql.jdbc.Driver");
            //2.ªÒµ√ ˝æ›ø‚µƒ¡¨Ω”
             conn = DriverManager.getConnection(URL, USER, PASSWORD);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    public static Connection getConnection(){
        return conn;
    }

}

这是对数据库的操作的代码：

import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.imooc.db.DBUtil;
import com.imooc.model.Login;


public class LoginDao {

    public void addLogin(Login l) throws Exception{
        Connection conn = DBUtil.getConnection();
        String sql=""+
                " insert into login"+"(id,yonghuming,mima,youxiang,zhucedate)"+
                " values("+
                 " ?,?,?,?,?)";
        PreparedStatement ptmt = conn.prepareStatement(sql);
        ptmt.setInt(1, l.getId());
        ptmt.setString(2, l.getYonghuming());
        ptmt.setString(3, l.getMima());
        ptmt.setString(4, l.getYouxiang());
        ptmt.setDate(5, new Date(l.getZhucedate().getTime()));

        ptmt.execute();

    }

    public void updateLogin(Login l) throws SQLException{
        Connection conn = DBUtil.getConnection();
        String sql=""+
                " update login"+
                " set id=?,yonghuming=?,mima=?,youxiang=?,zhucedate=? "+
                " where id = ?";
        PreparedStatement ptmt = conn.prepareStatement(sql);
        ptmt.setInt(1, l.getId());
        ptmt.setString(2, l.getYonghuming());
        ptmt.setString(3, l.getMima());
        ptmt.setString(4, l.getYouxiang());
        ptmt.setDate(5, new Date(l.getZhucedate().getTime()));

        ptmt.execute();
    }

    public void delLogin(Integer id) throws SQLException{
        Connection conn = DBUtil.getConnection();
        String sql=""+
                " delete from login "+
                " where id = ? ";
        PreparedStatement ptmt = conn.prepareStatement(sql);
        ptmt.setInt(1, id);

        ptmt.execute();
    }

    public List<Login> query() throws Exception{
        Connection conn = DBUtil.getConnection();
        Statement stmt=conn.createStatement();

        ResultSet rs = stmt.executeQuery("select id,mima,yonghuming,youxiang,zhucedate from login");

        List<Login> lg = new ArrayList<Login>();
        Login l = null;
        while(rs.next()){
            l=new Login();
            l.setId(rs.getInt("id"));
            l.setMima(rs.getString("mima"));
            l.setYonghuming(rs.getString("yonghuming"));
            l.setYouxiang(rs.getString("youxiang"));
            l.setZhucedate(rs.getDate("zhucedate"));
            lg.add(l);

        }
        return lg;
    }

    public List<Login> query(Integer yonghuming) throws Exception{
        Connection conn = DBUtil.getConnection();
        Statement stmt=conn.createStatement();

        ResultSet rs = stmt.executeQuery("select id,mima,yonghuming,youxiang,zhucedate from login where id = "+yonghuming);

        List<Login> lg = new ArrayList<Login>();
        Login l = null;
        while(rs.next()){
            l=new Login();
            l.setId(rs.getInt("id"));
            l.setMima(rs.getString("mima"));
            l.setYonghuming(rs.getString("yonghuming"));
            l.setYouxiang(rs.getString("youxiang"));
            l.setZhucedate(rs.getDate("zhucedate"));
            lg.add(l);

        }
        return lg;
    }
    public List<Login> getquery(Integer id) throws SQLException{
        Connection conn = DBUtil.getConnection();

        StringBuilder sb = new StringBuilder();
        sb.append("select * from login ");

        sb.append(" where id = ? ");
        System.out.println(sb.toString());
        PreparedStatement ptmt = conn.prepareStatement(sb.toString());
        ptmt.setInt(1, id);

        ResultSet rs = ptmt.executeQuery();
        List<Login> lg = new ArrayList<Login>();
        Login l = null;
        while(rs.next()){
            l=new Login();
            l.setId(rs.getInt("id"));
            l.setMima(rs.getString("mima"));
            l.setYonghuming(rs.getString("yonghuming"));
            l.setYouxiang(rs.getString("youxiang"));
            l.setZhucedate(rs.getDate("zhucedate"));
            lg.add(l);

        }
        return lg;
    }
}   

这个是登陆的实体类：

import java.util.Date;

public class Login {
    private int id;
    private String yonghuming;
    private String mima;
    private String youxiang;
    private Date zhucedate;
    public Date getZhucedate() {
        return zhucedate;
    }
    public void setZhucedate(Date zhucedate) {
        this.zhucedate = zhucedate;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getYonghuming() {
        return yonghuming;
    }
    public void setYonghuming(String yonghuming) {
        this.yonghuming = yonghuming;
    }
    public String getMima() {
        return mima;
    }
    public void setMima(String mima) {
        this.mima = mima;
    }
    public String getYouxiang() {
        return youxiang;
    }
    public void setYouxiang(String youxiang) {
        this.youxiang = youxiang;
    }

}