Retreiving list of keys from Map with certan value

[desmond5]

Hello,

I have a map (doesn't matter if it's hashmap or treemap or whaterer, just as long as it has keys and values).
I have several keys (of Person) in the map that have the same value (of Job).

public class Person
{
private String name;

public Person (String name) {
this.name = name;
}

@Override
public String toString() {
return this.name;
}
}

public class Job {

private String name;

public Job (String name) {
this.name = name;
}

@Override
public String toString() {
return this.name;
}
}

How can I retreive a list of keys which have the same value in the map ? Or In another words, how can I retreive a list of persons who all have the same Job ?
Is a map a good choice here at all ?

Many many thanks and best wishes,
desmond5

[hardwired]

Make up a method that will take the Job you are looking for and collect all Person keys in the map that have the same value as the Job argument.

Map<Person, Job> map = new HashMap<Person, Job>();

private List<Person> getPeopleByJob(Job job) {
    List<Person> list = new ArrayList<Person>();
    Set<Person> keys = map.keySet();
    Iterator<Person> it = keys.iterator();
    while(it.hasNext())
        Person person = (Person)it.next();
        if(map.get(person).equals(job))
            list.add(person);
    }
    return list;
}