LinkedHashMap - trying to use the method removeEldestEntry

[Nigel Shrin]

The program compiles but without using "removeEldestEntry", I am not sure if it should be inheriting a size() from HashMap, or whether I need to implement one, and if so what it should contain.
Perhaps I also need a different constructor for the LinkedHashMap. I have searched the ranch and web I have not found a clear example.

I think it should get called automatically from the put method on line 21.

import java.util.*;
public class LHM_removeEldestEntry {
	private static final int MAX_ENTRIES = 5;
//	public int size() {                  // override HashMap.size() ???
//        return size;
	protected boolean removeEldestEntry(Map.Entry<Integer, String> eldest) {
       return size() > MAX_ENTRIES;									
    }
	public static void main(String[] args) {
		LinkedHashMap<Integer, String> lhm = new LinkedHashMap<Integer, String>(MAX_ENTRIES+1);
//		String str[]={"01","02","03","04","05","06","07","08","09","10","11","12","13","14","15","16","17","18","19","20"};
		String str[]={"A","B","C","D","E","F","G","H","I","J","a","b","c","d","e","f","g","h","i","j"};
		for(String s : str)
		{
			int j=0;
			for(int i=0;i<s.length();i++)
			{
				j+=(int)s.charAt(i);
			}
		System.out.println("size is: " + lhm.size());
		lhm.put(j, s);
		}
		for(int int1 : lhm.keySet())
		{
			System.out.println(int1 + ": " + lhm.get(int1));
		}
	}
}

Many thanks!

[Nigel Shrin]

I've worked it out - though not 100% clear as to how it works. It appears the method needs to be within the constructor of LinkedHashMap.
Also the third argument in the constructor pertaining to the sort order has to be false.

Working version that keeps the last five entries only:

import java.util.*;
public class LHM_removeEldestEntry {
	private static final int MAX_ENTRIES = 5;
	public static void main(String[] args) {
		LinkedHashMap<Integer, String> lhm = new LinkedHashMap<Integer, String>(MAX_ENTRIES+1, .75F, false)
		{
			protected boolean removeEldestEntry(Map.Entry<Integer, String> eldest)
			{
			       return size() > MAX_ENTRIES;									
			 }
		};
//		String str[]={"01","02","03","04","05","06","07","08","09","10","11","12","13","14","15","16","17","18","19","20"};
		String str[]={"A","B","C","D","E","F","G","H","I","J","a","b","c","d","e","f","g","h","i","j"};
		for(String s : str)
		{
			int j=0;
			for(int i=0;i<s.length();i++)
			{
				j+=(int)s.charAt(i);
			}
			lhm.put(j, s);
		}
		for(int int1 : lhm.keySet())
		{
			System.out.println(int1 + ": " + lhm.get(int1));
		}
	}
}

Any further tips appreciated! thanks!