如何可以實現自定義排序到字段名稱的內容:排序的ArrayList
- 第一元件:P後面數字[1-9] {2}總是在第一
- 後跟:後面數字0 P [0-9]
- 接着:S
- 後面數字[1-9] {2}
,然後其餘的正常的順序
i1.getName().compareToIgnoreCase(i2.getName())
private static Comparator<Item> itemComperator = new Comparator<Item>() { @Override public int compare(Item i1, Item i2) { if (i1.getName().matches("P[1-9]{2}") && i2.getName().matches("P0[0-9]")) return -1; else if (i1.getName().matches("S[1-9]{2}")) return -1; else return i1.getName().compareToIgnoreCase(i2.getName()); } }; @Test public void sortItem() { Item item01 = new Item(1, "R59"); Item item02 = new Item(2, "S48"); Item item03 = new Item(3, "P01"); Item item04 = new Item(4, "P25"); Item item05 = new Item(5, "R99"); List<Item> items = Arrays.asList(item01, item02, item03, item04, item05); System.out.println("before sorting"); long seed = System.nanoTime(); Collections.shuffle(items, new Random(seed)); for (Item i : items) { System.out.println(i.getId() + " " + i.getName()); } System.out.println("after sorting"); Collections.sort(items, itemComperator); for (Item i : items) { System.out.println(i.getId() + " " + i.getName()); } } public class Item { private int id; private String name; public Item(int id, String name) { this.id = id; this.name = name; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
輸出預期:
after sorting
4 P25
3 P01
2 S48
1 R59
5 R99
您可以包括所需的輸出與問題.. ??? –