smbms系统项目环境搭建

搭建项目

1. 搭建一个maven项目
2. 配置tomcat
3. 测试项目是否能够跑起来
4. 导入项目中会遇到的jar包
   1. jsp
   2. servlet
   3. mysql驱动
   4. jstl
   5. standard
5. 创建项目的包结构
6. 编写实体类
   1. 对应于数据库的表属性
   2. ORM-映射：表-类映射
7. 编写基础公共类
   1. 数据库配置文件

      1. driver = com.mysql.jdbc.Driver
         url=jdbc:mysql://localhost:3306?useUnicode=true&characterEncoding=utf-8
         username=root
         password=123456Cy
   2. 编写数据库的实体类

      1. package com.lion.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 {
             //获取连接
             private static String driver;
             private static String url;
             private static String username;
             private static String password;
             //静态代码块，类加载的时候就已经初始化了
             static {
                 //通过类加载器获取对应的资源
                 InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");
                 Properties properties = new Properties();
                 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");
             }
             //获取数据库的连接
             public static Connection getConnection(){
                 Connection connection = null;
                 try {
                     Class.forName(driver);
                     connection = DriverManager.getConnection(url,username,password);
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
                 return connection;
             }
             //编写查询公共方法
             public static ResultSet execute(Connection connection,String sql,Object[] params,ResultSet resultSet,PreparedStatement preparedStatement) throws Exception {
                 preparedStatement = connection.prepareStatement(sql);
                 for (int i = 1; i < params.length; i++) {
                     preparedStatement.setObject(i+1,params[i]);
                 }
                 resultSet = preparedStatement.executeQuery();
                 return resultSet;
             }
             //编写增删改公共方法
             public static int execute(Connection connection,String sql,Object[] params,PreparedStatement preparedStatement) throws Exception {
                 preparedStatement = connection.prepareStatement(sql);
                 for (int i = 1; i < params.length; i++) {
                     preparedStatement.setObject(i+1,params[i]);
                 }
                 int i = preparedStatement.executeUpdate();
                 return i;
             }
             //关闭连接
             public static boolean close(Connection connection,ResultSet resultSet,PreparedStatement preparedStatement){
                 boolean flag = true;
                 if (connection != null){
                     try {
                         connection.close();
                         connection = null;
                     } catch (SQLException throwables) {
                         flag = false;
                         throwables.printStackTrace();
                     }
                 }
                 if (resultSet != null){
                     try {
                         resultSet.close();
                         resultSet = null;
                     } catch (SQLException throwables) {
                         flag = false;
                         throwables.printStackTrace();
                     }
                 }
                 if (preparedStatement != null){
                     try {
                         preparedStatement.close();
                         preparedStatement = null;
                     } catch (SQLException throwables) {
                         flag = false;
                         throwables.printStackTrace();
                     }
                 }
                 return flag;
             }
         
         }

   3. 编写字符编码过滤器

      1. public class CharacterEncodingFilter implements Filter {
             public void init(FilterConfig filterConfig) throws ServletException {
             }
             public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
                 request.setCharacterEncoding("utf-8");
                 response.setCharacterEncoding("utf-8");
                 chain.doFilter(request,response);
             }
             public void destroy() {
             }
         }

         <!--字符编码过滤器-->
         <filter>
             <filter-name>CharacterEncodingFilter</filter-name>
             <filter-class>com.lion.filter.CharacterEncodingFilter</filter-class>
         </filter>
         <filter-mapping>
             <filter-name>CharacterEncodingFilter</filter-name>
             <url-pattern>/*</url-pattern>
         </filter-mapping>