Java how to create a custom Exception to limit the size of a HashMap -

Java how to create a custom Exception to limit the size of a HashMap -

i have method inserts new items hashmap, want limit size of hashmap throw exception when size of hashmap larger specific value, 100, below implementation:

public void addtohashmap(string id, object value) throws hashmapoutofboundexception{ hashmap.put(id,value); } private class hashmapoutofboundexception extends exception{ //what should within class? }

why not simple:

public void addtohashmap(string id, object value) { if (hashmap.size()+1 > max_size) throw new hashmapoutofboundexception(); hashmap.put(id,value); }

with

public class hashmapoutofboundexception extends runtimeexception {}

from javadoc:

runtimeexception , subclasses unchecked exceptions. unchecked exceptions not need declared in method or constructor's throws clause if can thrown execution of method or constructor , propagate outside method or constructor boundary.

java exception