Question

我有学生列表，我需要使用更新列表进行更新。有点像：

 List<Student> students = new ArrayList<>();
 List<Update> updates = new ArrayList<>();

    ListIterator<Student> studentListIterator = students.listIterator();
    ListIterator<Update> updateListIterator = updates.listIterator();

    while (updateListIterator.hasNext()) {
        Update update = updateListIterator.next();
        int id = update.getId();
        while (studentListIterator.hasNext()) {
            Student student = studentListIterator.next();
            int studentId = student.getId();
            if (studentId == id) {
                student.setScore(update.getDynamicScore() + 10);
            }
        }
    }

Student.class：

 public class Student {
    int id;
    int score;
   }

更新课程：

 public class Update {
    private int id;
    private int dynamicScore;
}

如何使用RxJava代替

Answer 1

在迭代时，您必须使用LIstIterator修改列表本身。

ListIterator<Student> iter = students.listIterator();
while(iter.hasNext()){
   Student std = iter.next();
   // do your add/remove/edit operation here.....
}

Answer 2

您需要在observable中使用operator merge来合并两个列表。看看这个例子

 /**
 * Here we merge two list and we sort the list for every new item added into.
 * Shall return
 *
 * [1, 2, 3, 4, 5, 10, 11, 12, 13, 14, 15]
 */
@Test
public void testMergeLists() {
    Observable.merge(Observable.from(Arrays.asList(2, 1, 13, 11, 5)), Observable.from(Arrays.asList(10, 4, 12, 3, 14, 15)))
              .collect(ArrayList<Integer>::new, ArrayList::add)
              .doOnNext(Collections::sort)
              .subscribe(System.out::println);

}

如果您想了解有关RxJava的更多信息，请查看此处https://github.com/politrons/reactive

如何使用RxJava更新列表与另一个列表

2 个答案: