/**
 * 员工接受不同部门的数据访问。 
 * 但是不同部门访问该名员工获取的数据不相同。
 * 
 * @author zhangfly
 *
 * @param <T>
 */
public abstract class Employee<T> {

	public abstract void accept(Department department);

	public String getName() {
		return null;
	}

	public int getYear() {
		return 0;
	}

	public T getInfo() {
		return null;
	}
}

 

/**
 * 不同部门访问同一员工，访问的目的不同，获取的员工数据不同。
 * 
 * @author zhangfly
 *
 */
public abstract class Department {
	public abstract void visit(Employee employee);
}

 

public class EmployeeImpl extends Employee {
	private String name = "zhang";
	private int year = 2019;

	@Override
	public void accept(Department department) {
		department.visit(this);
	}

	@Override
	public String getName() {
		return name;
	}

	@Override
	public int getYear() {
		return year;
	}
}

 

/**
 * A，不同部门之一。
 * 
 * @author zhangfly
 *
 */
public class DepartmentA extends Department {
	@Override
	public void visit(Employee employee) {
		System.out.println("Department A 访问-> " + employee.getName());
	}
}

 

/**
 * B，不同部门之一。
 * 
 * @author zhangfly
 *
 */
public class DepartmentB extends Department {
	@Override
	public void visit(Employee employee) {
		System.out.println("Department B 访问-> " + employee.getYear());
	}
}

public class Test {
	public Test() {
		Employee employee = new EmployeeImpl();
		Department departmentA = new DepartmentA();
		Department departmentB = new DepartmentB();

		departmentA.visit(employee);
		departmentB.visit(employee);
		System.out.println("###分割线###");
		employee.accept(departmentB);
		employee.accept(departmentA);
	}

	public static void main(String[] args) {
		new Test();
	}
}

输出：

Department A 访问-> zhang
Department B 访问-> 2019
###分割线###
Department B 访问-> 2019
Department A 访问-> zhang