遍历HashMap

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

public class MapTest {

	public static void main(String[] args) {
		
		Map<String, Integer> map = new HashMap<String, Integer>();
		
		map.put("a", 1);
		map.put("b", 2);
		map.put("a", 2);
		
		Set<Entry<String, Integer>> set = map.entrySet();
		
		for(Iterator<Entry<String, Integer>> it = set.iterator();it.hasNext();){
			
			Entry<String, Integer> entry = it.next();
			
			System.out.println(entry.getKey()+" "+entry.getValue());
			
		}

		System.out.println(map.size());
		
	}

}