我有以下类(class):
public class Book implements Cloneable {
private int ISBN;
private String title;
private String publishDate;
private int pageCount;
}
我可以使用以下代码根据 Comparator
进行排序:
Comparator<Book> titleComparator = new Comparator<Book>() {
@Override
public int compare(Book o1, Book o2) {
return o1.title.compareTo(o2.title);
}
};
Comparator<Book> ISBNComparator = new Comparator<Book>() {
@Override
public int compare(Book o1, Book o2) {
return Integer.valueOf(o1.ISBN).compareTo(o2.ISBN);
}
};
public void sort(final String field, ArrayList<Book> BookList) {
final Comparator<Book> comparator;
if (field.equals("title")) {
comparator = titleComparator;
} else if (field.equals("ISBN")) {
comparator = ISBNComparator;
} else {
throw new IllegalArgumentException("Comparator not found for " + field);
}
Collections.sort(BookList, comparator);
}
但是当发布日期格式为“25/12/2015”时,如何根据字符串 publishDate 进行排序?
最佳答案
如果您确定不能选择使用 Date 而不是 String,请使用此比较器(您可以添加一些缓存以避免每次都解析字符串):
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Comparator;
/**
*
* @author EBudaqov
*/
public class StringDateComparator implements Comparator<String>{
private SimpleDateFormat formatter;
public StringDateComparator(String dateFormat) {
formatter = new SimpleDateFormat(dateFormat);
}
@Override
public int compare(String s1, String s2) {
try {
return formatter.parse(s1).compareTo(formatter.parse(s2));
} catch(ParseException exception) {
throw new RuntimeException(exception);
}
}
public static void main(String[] args) {
String s1 = "01/01/2015";
String s2 = "02/01/2015";
System.out.println(new StringDateComparator("dd/MM/yyyy").compare(s1, s2));
}
}
关于java - 根据比较器使用字符串日期排序?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34199929/