遍歷Map集合的兩種方式

	public class HashMapDemo {
			public static void main(String[] args) {
				//創建Map對象
				HashMap<String,String> hm = new HashMap<String,String>();
				//添加映射關係
				hm.put("ITCAST001", "張三");
				hm.put("ITCAST002", "李四");
				hm.put("ITCAST003", "王五");
				hm.put("ITCAST003", "趙六");
				//遍歷Map對象
				
				//方式1 獲取所有的key，通過key來獲取value
				Set<String> keys = hm.keySet();
				for (String key : keys) {
					String value = hm.get(key);
					System.out.println(key + "=" + value);
				}
				
				System.out.println("------------------");
				
				//方式2：獲取所有的結婚證對象，然後通過結婚證對象獲取丈夫和媳婦
				Set<Map.Entry<String, String>> entrys = hm.entrySet();
				for (Map.Entry<String, String> entry : entrys) {
					String key = entry.getKey();
					String value = entry.getValue();
					System.out.println(key + "=" + value);
				}
			}
		}