遍历Map集合的两种方式

	public class HashMapDemo {
			public static void main(String[] args) {
				//创建Map对象
				HashMap<String,String> hm = new HashMap<String,String>();
				//添加映射关系
				hm.put("ITCAST001", "张三");
				hm.put("ITCAST002", "李四");
				hm.put("ITCAST003", "王五");
				hm.put("ITCAST003", "赵六");
				//遍历Map对象
				
				//方式1 获取所有的key，通过key来获取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：获取所有的结婚证对象，然后通过结婚证对象获取丈夫和媳妇
				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);
				}
			}
		}