SMBMS项目搭建

package com.zang.dao;
import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;
//操作数据库的公共类
public class BaseDao {
    private static String driver;
    private static String url;
    private static String user;
    private static String password;
    //静态代码块，类加载的时候就初始化了
    static {
        try {
            //通过类加载器读取对应的资源
            InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");
            Properties properties = new Properties();
            properties.load(is);
            driver=properties.getProperty(driver);
            url=properties.getProperty(url);
            user=properties.getProperty(user);
            password=properties.getProperty(password);
            Class.forName(driver);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static Connection getconn(){
        Connection connection = null;
        try {
            connection = DriverManager.getConnection(url, user, password);
        } catch (Exception throwables) {
            throwables.printStackTrace();
        }
        return connection;
    }
    //编写查询公共类
    public static ResultSet execute(Connection connection ,String sql,Object[] params,ResultSet resultSet,PreparedStatement statement) throws SQLException {
        statement = connection.prepareStatement(sql);
        for (int i = 0; i <params.length; i++) {
            statement.setObject(i+1,params[i]);
        }
        resultSet = statement.executeQuery();
        return resultSet;
    }
    //编写增删改公共方法
    public static int execute(Connection connection ,String sql,Object[] params,PreparedStatement statement) throws SQLException {
        statement = connection.prepareStatement(sql);
        for (int i = 0; i <params.length; i++) {
            statement.setObject(i+1,params[i]);
        }
        int update = statement.executeUpdate();
        return update;
    }
    //释放资源
    public static boolean closeresourse(Connection connection,PreparedStatement preparedStatement,ResultSet resultSet){
        boolean flag=true;
        if(resultSet!=null){
            try {
                resultSet.close();
                resultSet=null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag=false;
            }
        }
        if(preparedStatement!=null){
            try {
                preparedStatement.close();
                preparedStatement=null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag=false;
            }
        }
        if(connection!=null){
            try {
                connection.close();
                connection=null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag=false;
            }
        }
        return flag;
    }
}