兩個list >放入一個list中

// public static void main(String[] args) {
// List<Map<String, String>> list2 = new ArrayList<Map<String,String>>();
// List<Map<String, String>> list3 = new ArrayList<Map<String,String>>();
// Map<String, String> map1=new HashMap();
// Map<String, String> map2=new HashMap();
// map1.put("1", "1");
// map1.put("2", "11");
// map1.put("3", "111");
// map2.put("1", "2");
// map2.put("2", "22");
// map2.put("3", "222");
// map2.put("4", "2222");
// map2.put("5", "22222");
// list2.add(map1);
// list3.add(map2);
// list2.addAll(list3);
// }

注意 list.addAll方法返回的是boolean值

 

 

java 兩條sql 從兩個不同的數據庫，查出兩個格式相同的數據集合，把他們合並在一起分頁

這種情況推薦使用guava（google出品的哦），為了簡潔，只放核心代碼，讓你瞬間有思路：

合並：

List<String> list1 = Arrays.asList("1","2","3","4","5","6","7"); List<String> list2 = Arrays.asList("2","3","4","5","6","7","8"); List<String> list = Lists.newArrayList(list1, list2);

分頁：

List<String> list = Arrays.asList("1","2","3","4","5","6","7"); List<List<String>> partition = ListUtils.partition(list, 2);//分頁數量

拓展-- 交差並集（可能對你有幫助）:

public static void main(String[] args) { Set<Integer> sets = Sets.newHashSet(1, 2, 3, 4, 5, 6); Set<Integer> sets2 = Sets.newHashSet(3, 4, 5, 6, 7, 8, 9); // 交集 System.out.println("交集為："); SetView<Integer> intersection = Sets.intersection(sets, sets2); for (Integer temp : intersection) { System.out.println(temp); } // 差集 System.out.println("差集為："); SetView<Integer> diff = Sets.difference(sets, sets2); for (Integer temp : diff) { System.out.println(temp); } // 並集 System.out.println("並集為："); SetView<Integer> union = Sets.union(sets, sets2); for (Integer temp : union) { System.out.println(temp); } }