JavaWeb【实战SMBMS超市管理系统】

SMBMS超市管理系统

SMBMS超市管理系统架构

数据库

项目如何搭建？

考虑使不使用Maven？依赖，Jar

项目搭建：

1.搭建一个maven web项目

2.配置Tomcat

3.测试项目能够跑起来

4.导入项目遇到的Jar包

jsp,servlet,mysql驱动，jstl,stand...

5.创建项目包结构

6.编写实体类

        ORM映射：表-类映射

7.编写基础公共类

        1.数据库配置文件

        db.propertiles

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306?useUnicode=true&characterEncoding=utf-8
username=root
password=123456

        2.编写数据库的公共类

package com.jiang.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 username;
    private  static  String password;

    //静态代码块，类加载的时候就初始化
    static {
        Properties properties = new Properties();

        //通过类加载器读取对应的资源
        InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.propertiles");
        try {
            properties.load(is);
        } catch (IOException e) {
            e.printStackTrace();
        }

        driver=properties.getProperty("driver");
        url=properties.getProperty("url");
        username=properties.getProperty("username");
        password=properties.getProperty("password");

    }

    //获取数据库连接
    public static Connection getConnectio(){
        Connection connection=null;
        try {
            Class.forName(driver);
           connection= DriverManager.getConnection(url,username,password);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return connection;
    }

    //编写查询公共类
    public static ResultSet execute(Connection connection,String sql,Object[] params,ResultSet resultSet,PreparedStatement preparedStatement) throws SQLException {
       preparedStatement = connection.prepareStatement(sql);

        for (int i = 0; i < params.length ; i++) {
            //setObject 占位符从1开始，但是数组是从0开始
            preparedStatement.setObject(i+1,params[i]);
        }
       resultSet = preparedStatement.executeQuery(sql);
        return  resultSet;
    }

    //编写增删改工具类
    public static int  execute(Connection connection,String sql,Object[] params,PreparedStatement preparedStatement) throws SQLException {
        //预编译的sql，在后面直接执行就可以了
        preparedStatement = connection.prepareStatement(sql);

        for (int i = 0; i < params.length ; i++) {
            //setObject 占位符从1开始，但是数组是从0开始
            preparedStatement.setObject(i+1,params[i]);
        }
        int updateRows = preparedStatement.executeUpdate(sql);
        return  updateRows;
    }

    //释放资源
    public static boolean closeResource(Connection connection,PreparedStatement preparedStatement,ResultSet resultSet){
        boolean flag=true;
        if(resultSet!=null){
            try {
                resultSet.close();
                //GC回收
                resultSet=null;
            } catch (SQLException e) {
                e.printStackTrace();
                flag=false;
            }
        }
        if(preparedStatement!=null){
            try {
                preparedStatement.close();
                //GC回收
                preparedStatement=null;
            } catch (SQLException e) {
                e.printStackTrace();
                flag=false;
            }
        }
        if(connection!=null){
            try {
                connection.close();
                //GC回收
                connection=null;
            } catch (SQLException e) {
                e.printStackTrace();
                flag=false;
            }
        }
        return flag;
    }



}

         3.编写字符编码过滤器

        

package com.jiang.filter;

import javax.servlet.*;
import java.io.IOException;

//编码过滤器
public class CharacterEncodingFilter implements Filter {

    public void init(FilterConfig filterConfig) throws ServletException {

    }

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        servletRequest.setCharacterEncoding("utf-8");
        servletResponse.setCharacterEncoding("utf-8");
        filterChain.doFilter(servletRequest,servletResponse);//继续往下放行
    }

    public void destroy() {

    }
}

8.导入静态资源