遍历 HashMap

public class TestHashMap {

		Map<String, Integer> tt = new HashMap<String, Integer>();
		tt.put("aaa", 1);
		tt.put("bbb", 2);
		tt.put("ccc", 3);
		tt.put("ddd", 4);

		Set<Entry<String, Integer>> temp = tt.entrySet();
		Iterator<Entry<String, Integer>> it = temp.iterator();
		
		while (it.hasNext()) {
			Entry<String, Integer> entry = it.next();
			System.out.println(entry.getKey() + "  " + entry.getValue());
		}

}



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

public class Student {
	private String name;
	private int id;

	public Student(int id, String name) {
		super();
		this.name = name;
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public static void main(String[] args) {

		Student st1 = new Student(0001, "张三");
		Student st2 = new Student(0002, "李四");
		Student st3 = new Student(0003, "王五");

		Map<Integer, String> map = new HashMap<Integer, String>();

		map.put(st1.getId(), st1.getName());
		map.put(st2.getId(), st2.getName());
		map.put(st3.getId(), st3.getName());

		Set<Integer> set = map.keySet();
		Iterator<Integer> it = set.iterator();

		while (it.hasNext()) {
			int i = it.next();
			String str = map.get(i);
			System.out.println("ID: " + i + "\t" + "姓名：" + str);

		}

	}

}