• 使用Servlet+Tomcat+MySQL开发-简易版部门信息管理系统（单表CRUD）

    为了检验JavaWeb、Servlet、MySQL、JDBC的学习效果，实现了简易版的部门信息管理系统。没有使用任何框架，这样便于深入理解原理。

    目录

    一、开发思路

    1. 设计系统功能

    2. 设计前端页面（5个，简单，文本编辑器即可，后期替换成java代码）

    3. IDEA中搭建开发环境

    4. 进行功能实现

    5. 实现JDBC工具类

    二、开发步骤

    步骤一：准备数据库表

    步骤二： 设计HTML页面（项目原型）

     步骤三：实现查看部门列表功能

    步骤四：类推，实现全部功能

    三、项目演示

    四、完整代码

    1. 完整目录结构

    2. 代码 

    web.xml

     前端页面2个：index.html 

    add.html

    后端功能实现类6个：DeptDeleteServlet.java 

    DeptDetialServlet.java 

    DeptEditServlet.java 

     DeptListServlet.java

    DeptSaveServlet.java 

    DeptUpdateServlet.java 

    一、开发思路

    前端->后端。即先设计前端页面及功能，然后后端连接MySQL实现功能。凡是与数据库产生交互的，成为功能。

    1. 设计系统功能

    • 查看部门列表

    • 新增部门

    • 删除部门

    • 查看部门详细信息

    • 跳转到修改页面

    • 修改部门

    2. 设计前端页面（5个，简单，文本编辑器即可，后期替换成java代码）

    • 欢迎页面index.html
    1. html>
    2. <html>
    3. 	<head>
    4. 		<meta charset="utf-8">
    5. 		<title>欢迎使用OA系统title>
    6. 	head>
    7. 	<body>
    8. 		<a href="list.html">查看部门列表a>
    9. 	body>
    10. html>
    • 部门列表页面
    1. html>
    2. <html>
    3. 	<head>
    4. 		<meta charset="utf-8">
    5. 		<title>部门列表页面title>
    6. 	head>
    7. 	<body>
    8.  
    9. <script type="text/javascript">
    10. 	function del(dno){
    11. 		// 弹出确认框，用户点击确定，返回true，点击取消返回false
    12. 		var ok = window.confirm("亲，删了不可恢复哦！");
    13. 		if(ok){
    14. 			// 发送请求进行删除数据的操作。
    15. 			// 在JS代码当中如何发送请求给服务器？
    16. 			//alert("正在删除数据，请稍后...")
    17.  
    18. 			//document.location.href = "请求路径"
    19. 			//document.location = "请求路径"
    20. 			//window.location.href = "请求路径"
    21. 			//window.location = "请求路径"
    22. 			document.location.href = "/oa/dept/delete?deptno=" + dno;
    23. 		}
    24. 	}
    25. script>
    26.  
    27. 		<h1 align="center">部门列表h1>
    28. 		<hr >
    29. 		<table border="1px" align="center" width="50%">
    30. 			<tr>
    31. 				<th>序号th>
    32. 				<th>部门编号th>
    33. 				<th>部门名称th>
    34. 				<th>操作th>
    35. 			tr>
    36. 			<tr>
    37. 				<td>1td>
    38. 				<td>10td>
    39. 				<td>销售部td>
    40. 				<td>
    41. 					<a href="javascript:void(0)" onclick="del(10)">删除a>
    42. 					<a href="edit.html">修改a>
    43. 					<a href="detail.html">详情a>
    44. 				td>
    45. 			tr>
    46. 			<tr>
    47. 				<td>2td>
    48. 				<td>20td>
    49. 				<td>研发部td>
    50. 				<td>
    51. 					
    52. 					
    53. 					
    54. 					<a href="javascript:void(0)" onclick="del(20)" >删除a>
    55. 					<a href="edit.html">修改a>
    56. 					<a href="detail.html">详情a>
    57. 				td>
    58. 			tr>
    59. 			<tr>
    60. 				<td>3td>
    61. 				<td>30td>
    62. 				<td>运营部td>
    63. 				<td>
    64. 					<a href="javascript:void(0)" onclick="del(30)" >删除a>
    65. 					<a href="edit.html">修改a>
    66. 					<a href="detail.html">详情a>
    67. 				td>
    68. 			tr>
    69. 		table>
    70. 		
    71. 		<hr >
    72. 		<a href="add.html">新增部门a>
    73. 		
    74. 	body>
    75. html>
    • 部门信息详情页面detail.html
    1. html>
    2. <html>
    3. 	<head>
    4. 		<meta charset="utf-8">
    5. 		<title>部门详情title>
    6. 	head>
    7. 	<body>
    8. 		<h1>部门详情h1>
    9. 		<hr >
    10. 		部门编号：20 <br>
    11. 		部门名称：销售部<br>
    12. 		部门位置：北京<br>
    13. 		
    14. 		<input type="button" value="后退" onclick="window.history.back()"/>
    15. 	body>
    16. html>
    • 修改部门信息页面edit.html
    1. html>
    2. <html>
    3. 	<head>
    4. 		<meta charset="utf-8">
    5. 		<title>修改部门title>
    6. 	head>
    7. 	<body>
    8. 		<h1>修改部门h1>
    9. 		<hr >
    10. 		<form action="list.html" method="get">
    11. 			部门编号<input type="text" name="deptno" value="20" readonly /><br>
    12. 			部门名称<input type="text" name="dname" value="销售部"/><br>
    13. 			部门位置<input type="text" name="loc" value="北京"/><br>
    14. 			<input type="submit" value="修改"/><br>
    15. 		form>
    16. 	body>
    17. html>
    • 新增部门信息页面add.html
    1. html>
    2. <html>
    3. 	<head>
    4. 		<meta charset="utf-8">
    5. 		<title>新增部门title>
    6. 	head>
    7. 	<body>
    8. 		<h1>新增部门h1>
    9. 		<hr >
    10. 		<form action="list.html" method="get">
    11. 			部门编号<input type="text" name="deptno"/><br>
    12. 			部门名称<input type="text" name="dname"/><br>
    13. 			部门位置<input type="text" name="loc"/><br>
    14. 			<input type="submit" value="保存"/><br>
    15. 		form>
    16. 	body>
    17. html>

    3. IDEA中搭建开发环境

    见这篇文章

    (437条消息) 基于IDEA的JAVAWeb-Servlet开发，实现网页对MySQL进行简单的CRUD_天亮有惊喜的博客-CSDN博客

    开发环境搭建完成后，需要把刚刚写的5个html文件复制在web文件夹内（与WEB-INF文件夹平级） ，并且另外开发DBUtil工具类（减少JDBC代码，每次使用同一个连接）

    开发环境的目录结构

     最终的目录结构如上图所示。

    4. 进行功能实现

    见下文《二、开发步骤》

    5. 实现JDBC工具类

    在src包中新建文件夹resources，其中新增配置文件jdbc.properties（遵守java的开闭原则）

    1. driver=com.mysql.cj.jdbc.Driver
    2. url=jdbc:mysql://localhost:3306/bjpowernode
    3. user=root
    4. password=123456

    新建包com.bjpowernode.oa->utils.DBUtil.java，系统的CRUD仅使用一次jdbc连接，减少系统资源浪费。同时抽象方法（如JDBC资源关闭方法），提高代码复用性。 

    1. package com.bjpowernode.oa.utils;
    2.  
    3. import java.sql.*;
    4. import java.util.ResourceBundle;
    5.  
    6. /**
    7.  * JDBC工具类
    8.  */
    9. public class DBUtil {
    10.     //静态变量：在类加载时执行，并且是有顺序的，自上而下
    11.     private static ResourceBundle bundle = ResourceBundle.getBundle("resources.jdbc");
    12.     private static String driver = bundle.getString("driver");
    13.     private static String url = bundle.getString("url");
    14.     private static String user = bundle.getString("user");
    15.     private static String password = bundle.getString("password");
    16.     static {
    17.         //注册驱动（驱动只需要注册一次，放在静态代码块中。DBUtil类加载的时候执行）
    18.         try {
    19.             //com.mysql.cj.jdbc.Driver是连接数据库的驱动，不能写死，因为以后可能还要连接Oracle数据库
    20.             //如果连接Oracle数据库，还需要修改java代码，显然违背了OCP开闭原则
    21.             //OCP开闭原则：对拓展开放，对修改关闭（功能拓展，不修改java源代码）
    22.             //Class.forName("com.mysql.cj.jdbc.Driver");
    23.             Class.forName(driver);
    24.         } catch (ClassNotFoundException e) {
    25.             throw new RuntimeException(e);
    26.         }
    27.     }
    28.  
    29.     /**
    30.      * 获取数据库连接对象
    31.      * @return conn 连接对象
    32.      * @throws SQLException
    33.      */
    34.     public static Connection getConnection() throws SQLException {
    35.         //获取连接
    36.         Connection conn = DriverManager.getConnection(url, user, password);
    37.         return conn;
    38.     }
    39.  
    40.     //注册驱动
    41.     //获取连接
    42.     //获取数据库操作对象
    43.     //执行SQL语句
    44.     //处理查询结果集
    45.  
    46.     /**
    47.      *释放资源
    48.      * @param conn 连接对象
    49.      * @param ps 数据库操作对象
    50.      * @param rs 结果集对象
    51.      */
    52.  
    53.     public static void close(Connection conn, Statement ps, ResultSet rs){
    54.         if (rs != null){
    55.             try {
    56.                 rs.close();
    57.             } catch (SQLException e) {
    58.                 e.printStackTrace();
    59.             }
    60.         }
    61.         if (ps != null){
    62.             try {
    63.                 ps.close();
    64.             } catch (SQLException e) {
    65.                 e.printStackTrace();
    66.             }
    67.         }
    68.         if (conn != null){
    69.             try {
    70.                 conn.close();
    71.             } catch (SQLException e) {
    72.                 e.printStackTrace();
    73.             }
    74.         }
    75.     }
    76. }

    二、开发步骤

    步骤一：准备数据库表

    保存以下代码脚本 depttest.sql，运行即生成数据库表bjpowernode.depttest

    1. # 部门表
    2. drop table if exists depttest;
    3. create table depttest(
    4. 	deptno int primary key,
    5.     dname varchar(255),
    6.     loc varchar(255)
    7. );
    8. insert into depttest(deptno, dname, loc) values(10, 'XiaoShouBu', 'BEIJING');
    9. insert into depttest(deptno, dname, loc) values(20, 'YanFaBu', 'SHANGHAI');
    10. insert into depttest(deptno, dname, loc) values(30, 'JiShuBu', 'GUANGZHOU');
    11. insert into depttest(deptno, dname, loc) values(40, 'MeiTiBu', 'SHENZHEN');
    12. commit;
    13. select * from depttest;
    库表bjpowernode.depttest

    步骤二： 设计HTML页面（项目原型）

    测试该5个页面，连接正常，整体符合预期（写好跳转即可）

     

     

     

     

     步骤三：实现查看部门列表功能

    web.xml配置修改如下

    1. <servlet>
    2.     <servlet-name>listservlet-name>
    3.     <servlet-class>com.bjpowernode.oa.web.action.DeptListServletservlet-class>
    4. servlet>
    5. <servlet-mapping>
    6.     <servlet-name>listservlet-name>
    7.     
    8.     <url-pattern>/dept/listurl-pattern>
    9. servlet-mapping>

     查看部门列表功能实现类com.bjpowernode.oa.web.action.DeptListServlet.java如下：

    1. package com.bjpowernode.oa.web.action;
    2.  
    3. import com.bjpowernode.oa.utils.DBUtil;
    4. import jakarta.servlet.ServletException;
    5. import jakarta.servlet.http.HttpServlet;
    6. import jakarta.servlet.http.HttpServletRequest;
    7. import jakarta.servlet.http.HttpServletResponse;
    8.  
    9. import java.io.IOException;
    10. import java.io.PrintWriter;
    11. import java.sql.Connection;
    12. import java.sql.PreparedStatement;
    13. import java.sql.ResultSet;
    14. import java.sql.SQLException;
    15.  
    16. public class DeptListServlet extends HttpServlet {
    17.     @Override
    18.     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    19.         doGet(request, response);
    20.     }
    21.  
    22.     @Override
    23.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    24.         //获取应用根路径
    25.         String contextPath = request.getContextPath();
    26.  
    27.         //tomcat10不用写,设置响应的内容类型以及字符集，防止中文乱码
    28.         response.setContentType("text/html;charset=UTF-8");
    29.         PrintWriter out = response.getWriter();
    30.  
    31.         //这部分是静态不变的
    32.         out.print("        ");
    33.         out.print("");
    34.         out.print("	");
    35.         out.print("		");
    36.         out.print("		部门列表页面");
    37.         out.print("	");
    38.         out.print("	");
    39.         out.print("		
      部门列表
      "      );
    40.         out.print("		
      "      );
    41.         out.print("		");
    42.         out.print("			
      43. ");
    43.         out.print("				
      44. ");
    44.         out.print("				
      45. ");
    45.         out.print("				
      46. ");
    46.         out.print("				
      47. ");
    47.         out.print("				
      48. ");
    48.         out.print("			
      49. ");
    49.  
    50.  
    51.         //连接数据库，查询所有部门
    52.         Connection conn = null;
    53.         PreparedStatement ps = null;
    54.         ResultSet rs = null;
    55.         try {
    56.             //获取连接
    57.             conn = DBUtil.getConnection();
    58.             //获取预编译的数据库操作对象
    59.             String sql = "select deptno, dname, loc from depttest";
    60.             ps = conn.prepareStatement(sql);
    61.             //执行sql语句
    62.             rs = ps.executeQuery();
    63.             //处理结果集
    64.             int i = 0;
    65.             String deptno = null;
    66.             String dname = null;
    67.             String loc = null;
    68.             while (rs.next()) {
    69.                 deptno = rs.getString("deptno");
    70.                 dname = rs.getString("dname");
    71.                 loc = rs.getString("loc");
    72.                 //这部分是动态的
    73.                 out.print("			
      74. ");
    74.                 out.print("				
      75. ");
    75.                 out.print("				
      76. ");
    76.                 out.print("				
      77. ");
    77.                 out.print("				
      78. ");
    78.                 out.print("				
      79. ");
    79.                 out.print("			
      80. ");
    80.             }
    81.             //这部分是静态不变的
    82.             out.print("            		
      83. 序号部门编号部门名称部门位置操作
      " + (++i) + "" + deptno + "" + dname + "" + loc + "");
    83.                 out.print("					删除");
    84.                 out.print("					修改");
    85. //                out.print("					详情");
    86.                 out.print("					详情");
    87.                 out.print("				
      88. "      );
    88.             out.print("		
      "      );
    89.             out.print("					新增部门");
    90.             out.print("	");
    91.             out.print("");
    92.  
    93.         } catch (SQLException e) {
    94.             e.printStackTrace();
    95.         } finally {
    96.             //释放资源
    97.             DBUtil.close(conn, ps, rs);
    98.         }
    99.     }
    100. }

    步骤四：类推，实现全部功能

    以此类推，实现全部功能：展示部门列表、查看部门详细信息、删除部门、新增部门信息、新增部门。完整目录结构如下所示：

    完整目录结构
    完整目录结构

     完整代码在下文《四、完整代码》给出

    三、项目演示

     

     

    四、完整代码

    1. 完整目录结构

    完整目录结构
    完整目录结构

    项目文件夹存放路径:.
    ├─.idea
    │  └─artifacts
    ├─oa
    │  ├─src
    │  │  ├─com.bjpowernode.oa
    │  │  │  └─utils
    │  │  │      └─DUBtil.java
    │  │  │  └─web.action
    │  │  │      └─DeptDeleteServlet.java
    │  │  │      └─DeptDetailServlet.java
    │  │  │      └─DeptEditServlet.java
    │  │  │      └─DeptListServlet.java
    │  │  │      └─DeptSavaServlet.java
    │  │  │      └─DeptUpdateServlet.java
    │  │  └─resources
    │  │  │  └─jdbc.properties
    │  └─web
    │  │  └─WEB-INF
    │  │  │  └─lib
    │  │  │      └─mysql-connector-java-8.0.28.jar
    │  │  │  └─web.xml
    │  │  └─index.html
    │  │  └─add.html
    │  └─oa.iml

    External Libraries

    │─jsp.api.jar
    │─servlet-api.kar
    │─jdk1.8.0_111

    2. 代码 

    web.xml

    1. "1.0" encoding="UTF-8"?>
    2. <web-app xmlns="https://jakarta.ee/xml/ns/jakartaee"
    3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    4.          xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_5_0.xsd"
    5.          version="5.0">
    6.  
    8.     <servlet>
    9.         <servlet-name>listservlet-name>
    10.         <servlet-class>com.bjpowernode.oa.web.action.DeptListServletservlet-class>
    11.     servlet>
    12.     <servlet-mapping>
    13.         <servlet-name>listservlet-name>
    14.         
    15.         <url-pattern>/dept/listurl-pattern>
    16.     servlet-mapping>
    17.  
    19.     <servlet>
    20.         <servlet-name>detailservlet-name>
    21.         <servlet-class>com.bjpowernode.oa.web.action.DeptDetailServletservlet-class>
    22.     servlet>
    23.     <servlet-mapping>
    24.         <servlet-name>detailservlet-name>
    25.         <url-pattern>/dept/detailurl-pattern>
    26.     servlet-mapping>
    27.  
    29.     <servlet>
    30.         <servlet-name>deleteservlet-name>
    31.         <servlet-class>com.bjpowernode.oa.web.action.DeptDeleteServletservlet-class>
    32.     servlet>
    33.     <servlet-mapping>
    34.         <servlet-name>deleteservlet-name>
    35.         <url-pattern>/dept/deleteurl-pattern>
    36.     servlet-mapping>
    37.  
    38.     
    39.     <servlet>
    40.         <servlet-name>saveservlet-name>
    41.         <servlet-class>com.bjpowernode.oa.web.action.DeptSaveServletservlet-class>
    42.     servlet>
    43.     <servlet-mapping>
    44.         <servlet-name>saveservlet-name>
    45.         <url-pattern>/dept/saveurl-pattern>
    46.     servlet-mapping>
    47.  
    48.     
    49.     <servlet>
    50.         <servlet-name>editservlet-name>
    51.         <servlet-class>com.bjpowernode.oa.web.action.DeptEditServletservlet-class>
    52.     servlet>
    53.     <servlet-mapping>
    54.         <servlet-name>editservlet-name>
    55.         <url-pattern>/dept/editurl-pattern>
    56.     servlet-mapping>
    57.  
    58.     
    59.     <servlet>
    60.         <servlet-name>updateservlet-name>
    61.         <servlet-class>com.bjpowernode.oa.web.action.DeptUpdateServletservlet-class>
    62.     servlet>
    63.     <servlet-mapping>
    64.         <servlet-name>updateservlet-name>
    65.         <url-pattern>/dept/updateurl-pattern>
    66.     servlet-mapping>
    67. web-app>

     前端页面2个：index.html 

    1. html>
    2. <html>
    3. 	<head>
    4. 		<meta charset="utf-8">
    5. 		<title>欢迎使用OA系统title>
    6. 	head>
    7.  
    8. 	<body>
    9. 		<a href="/oa/dept/list">查看部门列表a>
    10. 	body>
    11. html>

    add.html

    1. html>
    2. <html>
    3. 	<head>
    4. 		<meta charset="utf-8">
    5. 		<title>新增部门title>
    6. 	head>
    7. 	<body>
    8. 		<h1>新增部门h1>
    9. 		<hr >
    10. 		<form action="/oa/dept/save" method="post">
    11. 			部门编号<input type="text" name="deptno"/><br>
    12. 			部门名称<input type="text" name="dname"/><br>
    13. 			部门位置<input type="text" name="loc"/><br>
    14. 			<input type="submit" value="保存"/><br>
    15. 		form>
    16. 	body>
    17. html>

    后端功能实现类6个：DeptDeleteServlet.java 

    1. package com.bjpowernode.oa.web.action;
    2.  
    3. import com.bjpowernode.oa.utils.DBUtil;
    4. import jakarta.servlet.ServletException;
    5. import jakarta.servlet.http.HttpServlet;
    6. import jakarta.servlet.http.HttpServletRequest;
    7. import jakarta.servlet.http.HttpServletResponse;
    8.  
    9. import java.io.IOException;
    10. import java.io.PrintWriter;
    11. import java.sql.Connection;
    12. import java.sql.PreparedStatement;
    13. import java.sql.ResultSet;
    14. import java.sql.SQLException;
    15.  
    16. public class DeptDeleteServlet extends HttpServlet {
    17.     /**
    18.      * 根据部门编号展示部门信息，已经在DeptListServlet中传入了deptno
    19.      * @param request
    20.      * @param response
    21.      * @throws ServletException
    22.      * @throws IOException
    23.      */
    24.     @Override
    25.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    26.         // 获取部门编号
    27.         // /oa/dept/detail
    28.         String deptno = request.getParameter("deptno");
    29.         response.setContentType("text/html;charset=UTF-8");
    30.         PrintWriter out = response.getWriter();
    31.         //连接数据库，查询所有部门
    32.         Connection conn = null;
    33.         PreparedStatement ps = null;
    34.         ResultSet rs = null;
    35.         try {
    36.             //获取连接
    37.             conn = DBUtil.getConnection();
    38.             //获取预编译的数据库操作对象
    39.             String sql = "delete from depttest where deptno = ?";
    40.             ps = conn.prepareStatement(sql);
    41.             ps.setString(1, deptno);
    42.             //执行sql语句
    43.             int flag = ps.executeUpdate();
    44.             if(flag == 1){
    45.                 //删除成功
    46.                 request.getRequestDispatcher("/dept/list").forward(request, response);
    47.             }
    48.             else {
    49.                 //删除失败
    50.                 request.getRequestDispatcher("/error.html").forward(request, response);
    51.             };
    52.         } catch (SQLException e) {
    53.             e.printStackTrace();
    54.         } finally {
    55.             //释放资源
    56.             DBUtil.close(conn, ps, rs);
    57.         }
    58.     }
    59. }

    DeptDetialServlet.java 

    1. package com.bjpowernode.oa.web.action;
    2.  
    3. import com.bjpowernode.oa.utils.DBUtil;
    4. import jakarta.servlet.ServletException;
    5. import jakarta.servlet.http.HttpServlet;
    6. import jakarta.servlet.http.HttpServletRequest;
    7. import jakarta.servlet.http.HttpServletResponse;
    8.  
    9. import java.io.IOException;
    10. import java.io.PrintWriter;
    11. import java.sql.Connection;
    12. import java.sql.PreparedStatement;
    13. import java.sql.ResultSet;
    14. import java.sql.SQLException;
    15.  
    16. public class DeptDetailServlet extends HttpServlet {
    17.     /**
    18.      * 根据部门编号展示部门信息，已经在DeptListServlet中传入了deptno
    19.      * @param request
    20.      * @param response
    21.      * @throws ServletException
    22.      * @throws IOException
    23.      */
    24.     @Override
    25.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    26.         // 获取部门编号
    27.         // /oa/dept/detail
    28.         String deptno = request.getParameter("deptno");
    29.         response.setContentType("text/html;charset=UTF-8");
    30.         PrintWriter out = response.getWriter();
    31.  
    32.         //静态页面
    33.         out.print("");
    34.         out.print("");
    35.         out.print("	");
    36.         out.print("		");
    37.         out.print("		部门详情");
    38.         out.print("	");
    39.         out.print("	");
    40.         out.print("		
      部门详情
      "      );
    41.         out.print("		
      "      );
    42.  
    43.         //连接数据库，查询所有部门
    44.         Connection conn = null;
    45.         PreparedStatement ps = null;
    46.         ResultSet rs = null;
    47.         try {
    48.             //获取连接
    49.             conn = DBUtil.getConnection();
    50.             //获取预编译的数据库操作对象
    51.             String sql = "select dname, loc from depttest where deptno = ?";
    52.             ps = conn.prepareStatement(sql);
    53.             ps.setString(1, deptno);
    54.             //执行sql语句
    55.             rs = ps.executeQuery();
    56.             //处理结果集
    57.             int i = 0;
    58.             while(rs.next()) {
    59.                 String dname = rs.getString("dname");
    60.                 String loc = rs.getString("loc");
    61.                 //动态
    62.                 out.print("                       部门编号："+deptno+" 
      "      );
    63.                 out.print("                       部门名称："+dname+"
      "      );
    64.                 out.print("               部门位置："+loc+"
      "      );
    65.             }
    66.             //静态
    67.             out.print("		");
    68.             out.print("	");
    69.             out.print("");
    70.         } catch (SQLException e) {
    71.             e.printStackTrace();
    72.         } finally {
    73.             //释放资源
    74.             DBUtil.close(conn, ps, rs);
    75.         }
    76.     }
    77. }

    DeptEditServlet.java 

    1. package com.bjpowernode.oa.web.action;
    2.  
    3. import com.bjpowernode.oa.utils.DBUtil;
    4. import jakarta.servlet.ServletException;
    5. import jakarta.servlet.http.HttpServlet;
    6. import jakarta.servlet.http.HttpServletRequest;
    7. import jakarta.servlet.http.HttpServletResponse;
    8. import java.io.IOException;
    9. import java.io.PrintWriter;
    10. import java.sql.Connection;
    11. import java.sql.PreparedStatement;
    12. import java.sql.SQLException;
    13.  
    14. public class DeptEditServlet extends HttpServlet {
    15.     @Override
    16.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    17.         //初始化，得到当前路径，
    18.         response.setContentType("text/html;charset=UTF-8");
    19.         PrintWriter out = response.getWriter();
    20.         //获取数据库连接
    21.         Connection conn = null;
    22.         PreparedStatement ps = null;
    23.         String deptno = request.getParameter("deptno");
    24.         String dname = request.getParameter("dname");
    25.         String loc = request.getParameter("loc");
    26.  
    27.         out.print("           ");
    28.         out.print("");
    29.         out.print("	");
    30.         out.print("		");
    31.         out.print("		修改部门");
    32.         out.print("	");
    33.         out.print("	");
    34.         out.print("		
      修改部门
      "      );
    35.         out.print("		
      "      );
    36.         out.print("		
      ");
    37.         out.print("                    部门编号" readonly />
      "      );
    38.         out.print("                    部门名称">
      "      );
    39.         out.print("                    部门位置">
      "      );
    40.         out.print("			
      "      );
    41.         out.print("		");
    42.         out.print("	");
    43.         out.print("");
    44.     }
    45. }

     DeptListServlet.java

    1. package com.bjpowernode.oa.web.action;
    2.  
    3. import com.bjpowernode.oa.utils.DBUtil;
    4. import jakarta.servlet.ServletException;
    5. import jakarta.servlet.http.HttpServlet;
    6. import jakarta.servlet.http.HttpServletRequest;
    7. import jakarta.servlet.http.HttpServletResponse;
    8.  
    9. import java.io.IOException;
    10. import java.io.PrintWriter;
    11. import java.sql.Connection;
    12. import java.sql.PreparedStatement;
    13. import java.sql.ResultSet;
    14. import java.sql.SQLException;
    15.  
    16. public class DeptListServlet extends HttpServlet {
    17.     @Override
    18.     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    19.         doGet(request, response);
    20.     }
    21.  
    22.     @Override
    23.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    24.         //获取应用根路径
    25.         String contextPath = request.getContextPath();
    26.  
    27.         //tomcat10不用写,设置响应的内容类型以及字符集，防止中文乱码
    28.         response.setContentType("text/html;charset=UTF-8");
    29.         PrintWriter out = response.getWriter();
    30.  
    31.         //这部分是静态不变的
    32.         out.print("        ");
    33.         out.print("");
    34.         out.print("	");
    35.         out.print("		");
    36.         out.print("		部门列表页面");
    37.         out.print("	");
    38.         out.print("	");
    39.         out.print("		
      部门列表
      "      );
    40.         out.print("		
      "      );
    41.         out.print("		");
    42.         out.print("			
      43. ");
    43.         out.print("				
      44. ");
    44.         out.print("				
      45. ");
    45.         out.print("				
      46. ");
    46.         out.print("				
      47. ");
    47.         out.print("				
      48. ");
    48.         out.print("			
      49. ");
    49.  
    50.  
    51.         //连接数据库，查询所有部门
    52.         Connection conn = null;
    53.         PreparedStatement ps = null;
    54.         ResultSet rs = null;
    55.         try {
    56.             //获取连接
    57.             conn = DBUtil.getConnection();
    58.             //获取预编译的数据库操作对象
    59.             String sql = "select deptno, dname, loc from depttest";
    60.             ps = conn.prepareStatement(sql);
    61.             //执行sql语句
    62.             rs = ps.executeQuery();
    63.             //处理结果集
    64.             int i = 0;
    65.             String deptno = null;
    66.             String dname = null;
    67.             String loc = null;
    68.             while (rs.next()) {
    69.                 deptno = rs.getString("deptno");
    70.                 dname = rs.getString("dname");
    71.                 loc = rs.getString("loc");
    72.                 //这部分是动态的
    73.                 out.print("			
      74. ");
    74.                 out.print("				
      75. ");
    75.                 out.print("				
      76. ");
    76.                 out.print("				
      77. ");
    77.                 out.print("				
      78. ");
    78.                 out.print("				
      79. ");
    79.                 out.print("			
      80. ");
    80.             }
    81.             //这部分是静态不变的
    82.             out.print("            		
      83. 序号部门编号部门名称部门位置操作
      " + (++i) + "" + deptno + "" + dname + "" + loc + "");
    83.                 out.print("					删除");
    84.                 out.print("					修改");
    85. //                out.print("					详情");
    86.                 out.print("					详情");
    87.                 out.print("				
      88. "      );
    88.             out.print("		
      "      );
    89.             out.print("					新增部门");
    90.             out.print("	");
    91.             out.print("");
    92.  
    93.         } catch (SQLException e) {
    94.             e.printStackTrace();
    95.         } finally {
    96.             //释放资源
    97.             DBUtil.close(conn, ps, rs);
    98.         }
    99.     }
    100. }

    DeptSaveServlet.java 

    1. package com.bjpowernode.oa.web.action;
    2.  
    3. import com.bjpowernode.oa.utils.DBUtil;
    4. import jakarta.servlet.ServletException;
    5. import jakarta.servlet.http.HttpServlet;
    6. import jakarta.servlet.http.HttpServletRequest;
    7. import jakarta.servlet.http.HttpServletResponse;
    8.  
    9. import java.io.IOException;
    10. import java.io.PrintWriter;
    11. import java.sql.Connection;
    12. import java.sql.PreparedStatement;
    13. import java.sql.SQLException;
    14.  
    15. public class DeptSaveServlet extends HttpServlet {
    16.     /**
    17.      * 保存新增部门记录
    18.      * @param request
    19.      * @param response
    20.      * @throws ServletException
    21.      * @throws IOException
    22.      */
    23.     @Override
    24.     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    25.         // 获取部门编号
    26.         // /oa/dept/detail
    27.         String deptno = request.getParameter("deptno");
    28.         String dname = request.getParameter("dname");
    29.         String loc = request.getParameter("loc");
    30.         response.setContentType("text/html;charset=UTF-8");
    31.  
    32.         //连接数据库，查询所有部门
    33.         Connection conn = null;
    34.         PreparedStatement ps = null;
    35.         try {
    36.             //获取连接
    37.             conn = DBUtil.getConnection();
    38.             //获取预编译的数据库操作对象
    39.             String sql = "insert into depttest values(?, ?, ?)";
    40.             ps = conn.prepareStatement(sql);
    41.             ps.setString(1, deptno);
    42.             ps.setString(2, dname);
    43.             ps.setString(3, loc);
    44.  
    45. //            System.out.println(ps);
    46.             //执行sql语句
    47.             int flag = ps.executeUpdate();
    48. //            System.out.println("flag="+flag);
    49.             if(flag == 1){
    50.                 //执行成功
    51.                 request.getRequestDispatcher("/dept/list").forward(request, response);
    52.        //         request.getRequestDispatcher("/error.html").forward(request, response);
    53.             }else {
    54.                 //执行成功
    55.                 request.getRequestDispatcher("/error.html").forward(request, response);
    56.             }
    57.  
    58.         } catch (SQLException e) {
    59.             e.printStackTrace();
    60.         } finally {
    61.             //释放资源
    62.             DBUtil.close(conn, ps, null);
    63.         }
    64.     }
    65. }

    DeptUpdateServlet.java 

    1. package com.bjpowernode.oa.web.action;
    2.  
    3. import com.bjpowernode.oa.utils.DBUtil;
    4. import jakarta.servlet.ServletException;
    5. import jakarta.servlet.http.HttpServlet;
    6. import jakarta.servlet.http.HttpServletRequest;
    7. import jakarta.servlet.http.HttpServletResponse;
    8.  
    9. import java.io.IOException;
    10. import java.io.PrintWriter;
    11. import java.sql.Connection;
    12. import java.sql.PreparedStatement;
    13. import java.sql.SQLException;
    14.  
    15. public class DeptUpdateServlet extends HttpServlet {
    16.     @Override
    17.     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    18.         //初始化，得到当前路径，
    19.         response.setContentType("text/html;charset=UTF-8");
    20.         PrintWriter out = response.getWriter();
    21.         //获取数据库连接
    22.         Connection conn = null;
    23.         PreparedStatement ps = null;
    24.         String deptno = request.getParameter("deptno");
    25.         String dname = request.getParameter("dname");
    26.         String loc = request.getParameter("loc");
    27.         try {
    28.             conn = DBUtil.getConnection();
    29.             //执行sql语句
    30.             String sql = "update depttest set dname = ?, loc = ? where deptno = ?";
    31.             //获取预编译的sql语句
    32.             ps = conn.prepareStatement(sql);
    33.             ps.setString(1, dname);
    34.             ps.setString(2, loc);
    35.             ps.setString(3, deptno);
    36.             //执行sql语句
    37.             int flag = ps.executeUpdate();
    38.  
    39.             if(flag == 1){
    40.                 //执行成功
    41.                 request.getRequestDispatcher("/dept/list").forward(request, response);
    42.             } else {
    43.                 //执行失败
    44.                 request.getRequestDispatcher("/error.html").forward(request, response);
    45.             }
    46.         } catch (SQLException e) {
    47.             e.printStackTrace();
    48.         } finally {
    49.             DBUtil.close(conn, ps, null);
    50.         }
    51.     }
    52. }

    PS：虽然已经写得很详细了，可以直接1:1复现。但是如果有想要原项目工程代码的话，在评论区留下邮箱号即可，看到之后会回复哦~

  • 相关阅读:
    Redis_三种集群模式
    加速汽车行业转型，云计算到底扮演了什么角色？
    STM8的C语言编程（5）－－8位定时器应用之一
    QT基础入门【QSS】 伪状态，冲突解决、级联介绍
    kworker隔离绑定
    mysql_04_01_原理_索引下推
    学会这招，轻松实现英语文本转语音，巩固学习内容
    DBCO-SS-Mal，DBCO-SS-Maleimide，马来酰亚胺衍生物试剂特点分析
    纯CSS 毛玻璃效果
    微信小程序之投票管理
  • 原文地址：https://blog.csdn.net/weixin_42571453/article/details/127998776