AddressBook.java

import java.util.HashMap;

public class AddressBook {

  private HashMap<String, String> map = new HashMap<String, String>();

	public void record(String name, String tel) {
		map.put(name, tel);
	}

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

Main.java

public class Main {
  
	public static void main(String[] args) {
		
		AddressBook addr = new AddressBook();
		
		addr.record("pizza", "1112");
		addr.record("police", "191");
		
		System.out.println(addr.getNumber("pizza"));
		
		// TODO: make this work
		System.out.println(addr.getName("1112"));
		
	}
	
}