如何为HashMap创建一个remove方法

时间:2012-06-23 20:18:28

标签: java hashmap

我目前正在编写一个Employee商店,我需要能够删除商店的内容。

我该怎么做?

我已经有一个删除方法使用键删除它。但是当我在互联网上发现这个代码时,我不知道如何使用它。

这是我的代码:

MainApp

public class MainApp
{

    public static void main(String[] args)
    {
        new MainApp().start();

    }
    public void start()
    {
        EmployeeStore Store = new EmployeeStore();
        Store.add(new Employee ("James O' Carroll", 18,"hotmail.com"));

        Store.add(new Employee ("Andy Carroll", 1171,"yahoo.com"));

        Store.add(new Employee ("Luis Suarez", 7,"gmail.com"));
        Store.print();
        Store.clear();
        Store.print();

        Store.add(new Employee ("James O' Carroll", 18,"hotmail.com"));

        Store.add(new Employee ("Andy Carroll", 1171,"yahoo.com"));

        Store.add(new Employee ("Luis Suarez", 7,"gmail.com"));

        Store.print();
        Store.remove();


    }

}

EmployeeStore

//Imports.
import java.util.HashMap;
//********************************************************************
import java.util.Map;

public class EmployeeStore 
{
    HashMap<String, Employee> map;

//Constructor.  
    public EmployeeStore()
    {
        map = new HashMap<String,Employee>();
    }
//********************************************************************
//Hashmap Methods.
//Add to the Hashmap : Employee.
    public void add(Employee obj)
    {

        map.put(obj.getEmployeeName(), obj);
    }
//********************************************************************
//Remove from the Hashmap : Employee.
    public void remove(String key)
    {
      //Remove the Employee by name.
        map.remove(key);
    }
//********************************************************************
//Clear the Hashmap : Employee.
    public void clear()
    {
        map.clear();
    }
    //********************************************************************
//Print the Hashmap : Employee. 
    public void print()
    {
        System.out.println("\n********Employee's in the Company.********");
        for (Employee employee : map.values())
        {
            System.out.println("Employee Name:\t" + employee.getEmployeeName());
            System.out.println("Employee Id:\t" + employee.getEmployeeId());
            System.out.println("E-mail:\t"+ employee.getEmployeeEmail());
        }

    }


//********************************************************************  
//********************************************************************


}

员工

//Imports:

//********************************************************************
//Employee Class.
public class Employee
{
//Variables.
    private String employeeName;
    private int employeeId;
    private String employeeEmail;
//********************************************************************  
//Constructor.
    public Employee(String employeeName, int employeeId, String employeeEmail) 
    {
        this.employeeName = employeeName;
        this.employeeId = employeeId;
        this.employeeEmail = employeeEmail;
    }
//********************************************************************
//Getters.
    public String getEmployeeEmail() {
        return employeeEmail;
    }
    public void setEmployeeEmail(String employeeEmail) {
        this.employeeEmail = employeeEmail;
    }
    public String getEmployeeName() {
        return employeeName;
    }
    public int getEmployeeId() {
        return employeeId;
    }
//********************************************************************
//toString method.
    public String toString() {
        return "Employee [employeeName=" + employeeName + ", employeeId="
                + employeeId + ", employeeEmail=" + employeeEmail + "]";
    }
//********************************************************************





}

2 个答案:

答案 0 :(得分:1)

您的EmployeeStore使用HashMap来存储员工。每个员工都在地图中以其名称标识。要删除员工,只需拨打EmployeeStore.remove(String employeeName)

EmployeeStore employeeStore = new EmployeeStore();
employeeStore.add(new Employee ("James O' Carroll", 18,"hotmail.com"));
employeeStore.add(new Employee ("Andy Carroll", 1171,"yahoo.com"));
employeeStore.add(new Employee ("Luis Suarez", 7,"gmail.com"));

// Remove a certain employee
employeeStore.remove("Andy Carroll");

// Remove all employees
employeeStore.clear();

您应该注意两件事:

1 - 当前实施不允许两个或更多员工具有相同的名称,因为名称在地图中被用作键。

2 - 当您调用remove方法时,您必须提供确切的名称,因为Java中的String相等区分大小写。

您可能还想查看Map

答案 1 :(得分:0)

一个。为什么不使用HashMap的remove方法来解决这个问题呢?
B.此外,您可能希望按照某些标准执行删除 - 为此,您必须在地图上进行迭代,找到相关条目,获取其密钥,并按照A部分所述调用删除