java - EmployeeStore 的搜索方法。使用HashMap

Question

我目前正在申请存储员工详细信息，例如姓名、ID 和电子邮件地址。我正在使用 HashMap 来完成此操作。我目前在 searchByName、id 和电子邮件地址方法方面遇到困难。我该如何写一个？

这是我的代码:

//Imports.
import java.util.Scanner;
//********************************************************************  
public class MainApp
{
    private static Scanner keyboard = new Scanner(System.in);

    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();
   }
}

//Imports.
import java.util.HashMap;
//********************************************************************
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 employee)
    {

        map.put(employee.getEmployeeName(), employee);
    }
//********************************************************************
//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());
        }

    }
    public Employee get(String name){
        return map.get(name);
    }


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


}

//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 + "]";
    }
//********************************************************************





}

Answer 1

在您的 EmployeeStore 中，您可以添加您提到的各种方法:

1. searchByName 很容易实现，因为这是 map 的关键，所以一个简单的 map.get(name)应该可以解决问题
2. 对于另外 2 个，您有 2 个选择:
   • 为每种类型的搜索创建一个映射(因此您将并行维护 3 个映射，一个的键是名称，一个的键是电子邮件，一个的键是 ID)。每张 map 将包含相同的员工。您可以像 1 中那样实现搜索。这更快，但使用更多内存
   • 循环遍历 map ( for(Employee e : map.values()) {...} ) 的值并检查每个员工的电子邮件是否与搜索值匹配