smbms项目搭建

声明

本文部分内容参考自其他作者原创文章，仅供个人学习留档，特此声明

参考文章链接

(3条消息) 狂神说smbms项目（完整）_TTiamo_的博客-CSDN博客_狂神smbms

smbms项目搭建

1. 搭建一个模板maven webapp项目

2. 配置Tomcat

3. 测试项目能否运行起来

4. 导入所依赖的jar包：

   • servlet 实现servlet接口

   • jsp jsp标签

   • mysql-connector-java java连接数据库

   • jstl jsp标签库

   • standard jsp标签库所依赖的包

5. 搭建项目结构

   

6. 编写实体类

   ORM映射：表----->类

   

7. 编写基本公共类

   • 数据库配置文件

     

     driver=com.mysql.cj.jdbc.Driver
     url=jdbc:mysql://localhost:3306/smbms?useUnicode=true&characterEncoding=utf8&useSSL=false
     username=root
     password=xy680501*
     

   • 编写数据库的公共类

     

     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;
         //静态代码块在类加载的时候就初始化了
         static {
             //通过类加载器去读取对应的资源
             ClassLoader loader = BaseDao.class.getClassLoader();
             InputStream is = loader.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;
         }
         /*
        预编译的sql，执行的时候不需要传sql
         */
         //编写查询的公共类
         public static ResultSet execute(Connection connection, String sql, Object[] param, PreparedStatement statement, ResultSet resultSet){
             try {
                 statement = connection.prepareStatement(sql);
                 //setObject,占位符从1开始，但是数组的参数下标从0开始
                 for (int i = 0; i < param.length ; i++) {
                     statement.setObject(i+1,param[i]);//数组0给占位符1，数组1给2......
                 }
                 resultSet = statement.executeQuery();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
             return resultSet;
         }
     
         //编写增删改的公共类
         public static int execeute(Connection connection,String sql,Object[] param,PreparedStatement statement){
             int resultNum = 0;
             try {
                 statement = connection.prepareStatement(sql);
                 for (int i = 0; i < param.length ; i++) {
                     statement.setObject(i+1,param[i]);
                 }
                 resultNum = statement.executeUpdate();
     
             } catch (SQLException e) {
                 e.printStackTrace();
             }
             return resultNum;
         }
         //关闭资源的公共类
         public static boolean close(Connection connection,PreparedStatement statement,ResultSet resultSet){
             boolean flag = true;
             if (resultSet != null){
                 try {
                     resultSet.close();
                     //垃圾回收的操作
                     resultSet = null;
                 } catch (SQLException e) {
                     e.printStackTrace();
                     //如果没有释放成功
                     flag = false;
                 }
             }
             if (statement != null){
                 try {
                     statement.close();
                     statement = null;
                 } catch (SQLException e) {
                     e.printStackTrace();
                     flag = false;
                 }
             }
             if (connection != null){
                 try {
                     connection.close();
                     connection = null;
                 } catch (SQLException e) {
                     e.printStackTrace();
                     flag = false;
                 }
             }
             return flag;
     
         }
     }
     

   • 编写字符编码过滤器

     

     1.用于解决乱码的 CharacterEncodingFilter

     import javax.servlet.*;
     import java.io.IOException;
     
     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);
         }
     
         public void destroy() {
     
         }
     }
     

     2.注册

     <filter>
     	<filter-name>CharacterEncodingFilter</filter-name>
         <filter-class>/*</filter-class>
     </filter>
     

8. 导入静态资源