我这里有这段代码。 (此代码摘自《Thinking in Java 4th Edition》)
//{Args: "D.*\.java}
import java.util.regex.*;
import java.io.*;
import java.util.*;
public class DirList {
public static void main (String[] args){
File path = new File(".");
String[] list;
if(args.length == 0)
list = path.list();
else
list = path.list(new DirFilter(args[0]));
Arrays.sort(list,String.CASE_INSENSITIVE_ORDER);
for(String dirItem : list ){
System.out.println(dirItem);
}
}
}
class DirFilter implements FilenameFilter{
private Pattern pattern;
public DirFilter(String regex){
pattern = Pattern.compile(regex);
}
public boolean accept(File Dir,String name){
return pattern.matcher(name).matches();
}
}
然后当我阅读它的解释时我遇到了这个
DirFilter
’s sole reason for existence is to provide theaccept( )
method to thelist( )
method so thatlist( )
can "call back"accept( )
to determine which file names should be included in the list. Thus, this structure is often referred to as a callback.
回调具体是什么?
最佳答案
回调是您向正在使用的库提供的一种方法,以便该库可以调用您的方法来执行工作(或者更确切地说,回调您的代码,从而得名)。
更一般地说,任何两层代码都可以通过回调函数进行交互。
关于java - java中的回调是什么?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/11838917/