Question

I need for Search method for a hashmap and I cant quite figure out how to do it. I’m also trying to do a edit method and I think for this I need the method. My hashMap is to store employee data. I have the MainApp, Employee class and an EmployeeStore class. Can anyone help?

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("Andy Carroll");
        Store.print();


    }

}


//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());
        }

    }


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


}

//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

Since this is homework I’ll only guide you.

You have two options:

First of them is to create additional maps, mapping id–Employee and email–Employee, then fill all three maps when adding new employee. Getting employee would require to use Map.get(key) method on one of those maps.

Second, seems like better suiting your need, option is to retrieve all values from map – using Map.values(), iterate over them (using foreach), and check if id or email of given employee is the one that you was looking for – using object.equals(object2) method.

and one last thing – try to write clean code, so be precise in naming – in place of:

public void add(Employee obj)
{
    map.put(obj.getEmployeeName(), obj);
}

try following:

public void add(Employee employee)
{
    map.put(employee.getEmployeeName(), employee);
}

It does make the difference, trust me 🙂

EDIT:

Going back to naming advice – When you have class Named Employee its redundant to name method with word Employee within – as you did with employee.getEmployeeName().

It’s quite obvious, that you want to get name of empoyee, not his dog, nor couch 🙂 employee.getName() (that gets value of field named name – not myName or employeeName) is simpliest and best idea that you shoud have 🙂