学步园

第一种类型<String>之类的

		List<Integer> list = new ArrayList<Integer>();
		list.add(1);
		list.add(2);
		list.add(3);
		list.add(4);

第二种类型<Object>对象

		class Person{
			String name;
			String address;

			public Person(String name, String address) {
				this.name = name;
				this.address = address;
			}
		}
		
		List<Person> list2=new ArrayList<Person>();
		Person person = new Person("tom", "北京");
		Person person2 = new Person("jim","上海");
		Person person3 = new Person("kim","宁波");
		list2.add(person);
		list2.add(person2);
		list2.add(person3);

第三种Map<     ,      >

Map<String, String> student = new HashMap<String, String>();
		student.put("name", "tom");
		student.put("address", "北京");
		Set<String> keys= student.keySet();
		Iterator<String> iterator=keys.iterator();
		while(iterator.hasNext()){
			System.out.println(iterator.next());
		}

第四种与第二种效果一样,表达方式不同

List<Map<String,String>> list4 = new ArrayList<Map<String, String>>();
		Map<String, String> map1 = new HashMap<String,String>();
		map1.put("name","tom");
		map1.put("address", "北京");
		Map<String, String> map2 = new HashMap<String,String>();
		map2.put("name","jim");
		map2.put("address", "上海");
		Map<String, String> map3 = new HashMap<String,String>();
		map3.put("name","kim");
		map3.put("address", "宁波");
		list4.add(map1);
		list4.add(map2);
		list4.add(map3);