package com.pkm.annotation;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
/**
*
* @author Pritom
*/
public class HashMapIterator {
public static void main(String[] args) {
Map map = new HashMap();
map.put("key1", "Value 1");
map.put("key2", "Value 2");
map.put("key3", "Value 3");
map.put("key4", "Value 4");
map.put("key5", "Value 5");
/* Using Iterator */
System.out.println("Using Iterator");
Iterator iterator = map.entrySet().iterator();
while(iterator.hasNext()) {
Map.Entry mapEntry = (Map.Entry) iterator.next();
System.out.println("Key: " + mapEntry.getKey() + ", Value: " +
mapEntry.getValue());
if(mapEntry.getKey().toString().equals("key3")) {
/* Removing without ConcurrentModificationException */
iterator.remove();
}
}
/* Using Direct Entry Set */
System.out.println("\nUsing Direct Entry Set");
for (Object entry : map.entrySet()) {
Map.Entry mapEntry = (Map.Entry) entry;
System.out.println("Key : " + mapEntry.getKey() + ", Value : "
+ mapEntry.getValue());
}
/* Using Direct Key Set */
System.out.println("\nUsing Direct Key Set");
for (Object entry : map.keySet()) {
System.out.println("Key : " + entry + ", Value : "
+ map.get(entry));
}
}
}
Using Iterator
Key: key4, Value: Value 4
Key: key3, Value: Value 3
Key: key5, Value: Value 5
Key: key2, Value: Value 2
Key: key1, Value: Value 1
Using Direct Entry Set
Key : key4, Value : Value 4
Key : key5, Value : Value 5
Key : key2, Value : Value 2
Key : key1, Value : Value 1
Using Direct Key Set
Key : key4, Value : Value 4
Key : key5, Value : Value 5
Key : key2, Value : Value 2
Key : key1, Value : Value 1
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