import java.util.ArrayList;import java.util.List; public class NoteBook { private List<String> list; public NoteBook(){ list = new ArrayList(); } public NoteBook(List<String> list){ this.list = list; } //存储记录 //不限制能存储的记录条数 public String save(String s){ if (list.add(s)) { return "存储成功"; } return "存储失败"; } //获取记录条数 public int getSum() { return list.size(); } //查看每条记录 public String getAnyOne(int i) { if (i > 0 && i < list.size()) { return list.get(i); } return "没有此记录"; } public String getAnyOne() { if (list.size() == 0) { return "没有此记录"; } return list.get(0); } //删除记录 public String deleteOne() { if (list.size() == 0) { return "没有此记录"; } return list.remove(0); } public String deleteOne(int i) { if (i > 0 && i < list.size()) { list.remove(i); return "已经移除"; } return "没有此记录"; } public void showAll() { list.forEach(s-> System.out.println(s)); } public static void main(String[] ages){ NoteBook noteBook = new NoteBook(); noteBook.save("记录0"); noteBook.save("记录1"); noteBook.save("记录2"); noteBook.save("记录3"); System.out.println("插入结果:"+noteBook.save("记录4")); System.out.println("删除结果："+noteBook.deleteOne()); System.out.println("获得条目： "+noteBook.getSum()); System.out.println("列出一条： "+noteBook.getAnyOne(1)); noteBook.showAll(); } }