java - 当 hashmap 中的键看起来像 :entry. getBname.getTitle() 时，如何识别它

Question

当我在做hashmap编码时，我遇到了一个碰撞来识别key，示例如下:

public void addBE(BookEntry entry)
{
library.put(entry.getBname().getTitle(), entry);
}

对于这个例子，getBname() 或 getTitle 是这个的键吗？，entry 应该是值，对吗？但是entry代表的是一个类，那么是否意味着entry中的所有内容都是值？

感谢您解答我的疑问。

仅供引用:BookEntry 类:

public class BookEntry{
private BookName bname;
private Writer wname;
private BookID b_id;

public BookEntry(BookName bname, Writer wname, BookID b_id)
{
this.bname = bname;
this.wname = wname;
this.b_id = b_id;
}

public BookName getBname()
{
return bname;
}
public Writer getWname()
{
return wname;
}
public BookID getBookID()
{
return b_id;
}
public String toString()
{
return bname.toString() + " " + wname.toString() + " " + b_id.toString();
}

public static BookEntry enterBE()
{
BookName bname = BookName.enterName();
Writer wname = Writer.enterWriter();
BookID b_id = BookID.enterID();
return new BookEntry(bname, wname, b_id);
}
}

Answer 1

关键是标题，即 getTitle() 的输出。它将与以下内容相同:

String titleKey = entry.getBname().getTitle(); // assuming title is a String, but it could be any type
library.put(titleKey, entry);