lets say I have a Employee-class with Instant- and Id-Attribute:
public class Employee implements Comparable<Employee> {
private Instant workEnd;
private Integer id;
private String name;
public Instant getWorkEnd() {
return workEnd;
}
public void setWorkEnd(Instant workEnd) {
this.workEnd = workEnd;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public int compareTo(Employee employee) {
int workEndCompare = getWorkEnd().compareTo(employee.getWorkEnd());
int idCompare = getId().compareTo(employee.getId());
if (workEndCompare == 0) {
return idCompare;
} else {
return workEndCompare;
}
}
@Override
public String toString() {
return String.format("{Date: %s,Number: %d}", getWorkEnd(), getId());
}
}
As you can see each Employee-Object sorts dependent on workEnd and id.
Now I want to put these Employee-Objects as Keys in a HashMap. But I want that the HashMap replaces each Key-Employee with the put()-method if the attributes workend and id are equal. Thta means I want the normal behaviour of a HashMap but with own custom Objects as Mapkeys.
How I manage that? By implementing the equals-method?
I tried something like that, but it does not work:
@Override
public boolean equals(Object obj) {
if (obj instanceof Employee) {
Employee employee = (Employee) obj;
int workEndCompare = getWorkEnd().compareTo(employee.getWorkEnd());
int idCompare = getId().compareTo(employee.getId());
if ((idCompare + workEndCompare) == 0) {
return true;
} else {
return false;
}
} else {
return super.equals(obj);
}
}
