Java 如何在指定目录中查找文件

以下实例演示了在 C 盘中查找以字母 'b' 开头的所有文件:
import java.io.*;

class Main {
   public static void main(String[] args) {
      File dir = new File("C:");
      FilenameFilter filter = new FilenameFilter() {
         public boolean accept
         (File dir, String name) {
            return name.startsWith("b");
        }
      };
      String[] children = dir.list(filter);
      if (children == null) {
         System.out.println("目录不存在或它不是一个目录");
      } 
      else {
         for (int i=0; i < children.length; i++) {
            String filename = children[i];
            System.out.println(filename);
         }
      } 
   }
}