Question

我要访问Book类内部的Page类的数据。（例如t_export_details）
我确实喜欢b.pages.getPageNum() 但这是行不通的。我无法访问Page类方法。如何访问？
谢谢。

b.pages = p;

public class Book<Page> {
  private String name;

  ArrayList<Page> pages = new ArrayList<Page>();

  public Book(String name) {
    this.name = name;
  }

  public String getBook() {
    return name;
  }
}

public class Main {
  public static void main(String[] args) {

    ArrayList<Page> p = new ArrayList<>();
    Page p1 = new Page(22);
    Page p2 = new Page(33);
    Page p3 = new Page(44);
    Page p4 = new Page(55);
    p.add(p1);
    p.add(p2);
    p.add(p3);
    p.add(p4);

    Book b = new Book("harrypotter");
    b.pages = p;
  }
}

Answer 1

创建公共获取者的二传手

public class Book {
  private String name;

  ArrayList<Page> pages = new ArrayList<Page>();

  public Book(String name) {
    this.name = name;
  }

  public String getBook() {
    return name;
  }

  public List<Page> getPages() {
    return this.pages;
  }

  public void setPages(List<Page> pages) {
    this.pages = pages;
  }
}

然后设置

b.setPages(p);

或访问页面

b.getPages().get(0).getPageNum();

Answer 2

public class Book<Page> implements Iterable<Page> {

  private String name;

  ArrayList<Page> pages = new ArrayList<>();

  public Book(String name) {
    this.name = name;
  }

  public String getBook() {
    return name;
  }

  public ArrayList<Page> getPages() {
    return this.pages;
  }

  public void setPages(ArrayList<Page> pages) {
    this.pages = pages;
  }

  @Override
  public Iterator<Page> iterator() {
    BookIterator bookIterator = new BookIterator<Page>();
    bookIterator.pages = this.pages;
    return bookIterator;
  }
}

public class Main {
  public static void main(String[] args) {

    ArrayList<Page> p = new ArrayList<>();
    Page p1 = new Page(22, true);
    Page p2 = new Page(33, false);
    Page p3 = new Page(44, true);
    Page p4 = new Page(55, false);
    p.add(p1);
    p.add(p2);
    p.add(p3);
    p.add(p4);

    Book b = new Book("harrypotter", BookCategory.NOVEL);
    b.setPages(p);
    b.getPages().get(0).getPageNum();

  }
}

private int pageNum;

  public Page(int pageNum) {
    this.pageNumber = pageNum;
  }

  public int getPageNumber() {
    return pageNum;
  }
}

我想访问Book类中的Page类的数据

2 个答案: