Java 实现员工添加功能并实时展示新员工信息

首先，在添加员工的页面上，需要一个提交按钮，点击提交按钮时，将表单数据发送到服务器端进行处理。
在服务器端，可以使用Java的Servlet技术来处理表单数据，并将员工信息保存到数据库中。
添加成功后，可以使用Java的重定向功能将页面跳转到显示所有员工的页面。
在显示所有员工的页面上，可以使用Java的JDBC技术从数据库中读取所有员工信息，并将其展示在页面上。

示例代码如下：

添加员工的页面：

<form action='addEmployee' method='post'>
  姓名：<input type='text' name='name'><br/>
  年龄：<input type='text' name='age'><br/>
  性别：<input type='radio' name='gender' value='男'>男
        <input type='radio' name='gender' value='女'>女<br/>
  部门：<input type='text' name='department'><br/>
  <input type='submit' value='提交'>
</form>

处理员工信息的Servlet：

@WebServlet('/addEmployee')
public class AddEmployeeServlet extends HttpServlet {
  private EmployeeDao employeeDao;

  public void init() {
    employeeDao = new EmployeeDao();
  }

  protected void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    String name = request.getParameter('name');
    int age = Integer.parseInt(request.getParameter('age'));
    String gender = request.getParameter('gender');
    String department = request.getParameter('department');
    Employee employee = new Employee(name, age, gender, department);
    employeeDao.addEmployee(employee);
    response.sendRedirect('showEmployees');
  }
}

显示员工信息的Servlet：

@WebServlet('/showEmployees')
public class ShowEmployeesServlet extends HttpServlet {
  private EmployeeDao employeeDao;

  public void init() {
    employeeDao = new EmployeeDao();
  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    List<Employee> employees = employeeDao.getAllEmployees();
    request.setAttribute('employees', employees);
    request.getRequestDispatcher('showEmployees.jsp').forward(request, response);
  }
}

显示员工信息的JSP页面：

<%@ page language='java' contentType='text/html; charset=UTF-8'
    pageEncoding='UTF-8'%>
<!DOCTYPE html>
<html>
<head>
<meta charset='UTF-8'>
<title>显示所有员工</title>
</head>
<body>
  <table border='1'>
    <tr>
      <th>姓名</th>
      <th>年龄</th>
      <th>性别</th>
      <th>部门</th>
    </tr>
    <%@ page import='java.util.List' %>
    <%@ page import='com.example.Employee' %>
    <% List<Employee> employees = (List<Employee>) request.getAttribute('employees'); %>
    <% for (Employee employee : employees) { %>
      <tr>
        <td><%= employee.getName() %></td>
        <td><%= employee.getAge() %></td>
        <td><%= employee.getGender() %></td>
        <td><%= employee.getDepartment() %></td>
      </tr>
    <% } %>
  </table>
</body>
</html>