2.3编写JavaBean (代码) 2.4编写EmployeeDao (代码) 2.5员工列表(需补充相关的实现过程) 2.6新增员工(需补充相关的实现过程) 2.7修改员工(需补充相关的实现过程) 2.8删除员工

在Java中，我们通常会使用Spring框架结合Hibernate来进行持久化操作。这里是一个简单的示例，展示了如何实现上述功能：

**2.3 编写JavaBean (Employee.java)**

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Employee {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String name;
    private String department;

    // getters and setters
    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    public String getDepartment() { return department; }
    public void setDepartment(String department) { this.department = department; }
}

**2.4 编写EmployeeDao (EmployeeDao.java)**

import org.springframework.stereotype.Repository;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;

@Repository
@Transactional
public class EmployeeDao {
    @Autowired
    private SessionFactory sessionFactory;

    public void save(Employee employee) {
        sessionFactory.getCurrentSession().save(employee);
    }

    public Employee findById(Long id) {
        return (Employee) sessionFactory.getCurrentSession().get(Employee.class, id);
    }

    // 其他CRUD操作，如 update, delete 等...
}

**2.5 员工列表**

List<Employee> employees = employeeDao.findAll(); // 使用EmployeeDao中的findAll方法获取所有员工
for (Employee employee : employees) {
    System.out.println("ID: " + employee.getId() + ", Name: " + employee.getName());
}

**2.6 新增员工 (EmployeeService.java)**

public void addEmployee(Employee newEmployee) {
    employeeDao.save(newEmployee);
}

**2.7 修改员工 (updateEmployee方法在EmployeeService.java)**

public void updateEmployee(Long id, Employee updatedEmployee) {
    Employee existingEmployee = employeeDao.findById(id);
    if (existingEmployee != null) {
        existingEmployee.setName(updatedEmployee.getName());
        existingEmployee.setDepartment(updatedEmployee.getDepartment());
        employeeDao.update(existingEmployee);
    }
}

**2.8 删除员工**

public void deleteEmployee(Long id) {
    Employee employeeToDelete = employeeDao.findById(id);
    if (employeeToDelete != null) {
        employeeDao.delete(employeeToDelete);
    }
}