SUBMS项目搭建准备工作

SUBMS项目搭建准备工作

1. 搭建一个maven web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

   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

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

   2. 编写数据库的公共类

      package com.yang.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了
          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.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;
          }
      
          //编写查询公共类
          public static ResultSet execute(Connection connection,String sql,Object[] params,ResultSet resultSet,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++) {
                 preparedStatement.setObject(i+1,params[i]);
              }
              resultSet = preparedStatement.executeQuery(sql);
              return resultSet;
          }
      
          //编写增删改公共方法
          public static int execute(Connection connection,String sql,Object[] params,PreparedStatement preparedStatement) throws SQLException {
              preparedStatement = connection.prepareStatement(sql);
      
              for (int i = 0; i < params.length; i++) {
                  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

8. 导入静态资源