Java:使用Collat​​orKey对集合进行排序

Question

我想要实现的是通过字符串值对对象的集合进行排序.但是,使用collat​​or以依赖于语言环境的方式.由于性能原因,我不想使用Collat​​or compare()方法(如下面的代码中)而不是Collat​​ionKey类,因为java API声明使用Collat​​ionKey要快得多.

但是如何使用Collat​​ionKey实现compareTo()方法？据我所知,如果我将使用Collat​​ionKey,我必须自己完全编写所有的比较方法.所以我甚至不再能够使用Collections.sort()方法......我非常感谢一个易于理解的示例,以及使用Collat​​ionKey对Person对象的Collection进行排序的最有效实现.

谢谢!

public class Person implements Comparable<Person> {

String lastname;

public int compareTo(Person person) {
     //This works but it is not the best implementation for a good performance
     Collator instance = Collator.getInstance(Locale.ITALY);
     return instance.compare(lastname, person.lastname);
}
}

...
ArrayList list = new ArrayList();
Person person1 = new Person("foo");
list.add(person1);
Person person2 = new Person("bar");
list.add(person2);
Collections.sort(list);
...

Answer 1

class Person implements Comparable<Person> {

  private static final Collator collator = Collator.getInstance(Locale.ITALY);

  private final String lastname;

  private final CollationKey key;

  Person(String lastname) {
    this.lastname = lastname;
    this.key = collator.getCollationKey(lastname);
  }

  public int compareTo(Person person) {
     return key.compareTo(person.key);
  }

}