import java.aa*;
public class FileList {
public static void main(String[] args) {
File f = new File("d:/A");
System.out.println(f.getName());
tree(f, 1);
}

private static void tree(File f, int level) {

String preStr = "";
for(int i=0; i<level; i++) {
preStr += "    ";
}

File[] childs = f.listFiles();
for(int i=0; i<childs.length; i++) {
System.out.println(preStr + childs[i].getName());
if(childs[i].isDirectory()) {
tree(childs[i], level + 1);
}
}
}

}

为什么我的第一句import java.aa*;会出错。？ 求大神!

import java.aa*;
public class FileList {
public static void main(String[] args) {
File f = new File("d:/A");
System.out.println(f.getName());
tree(f, 1);
}

private static void tree(File f, int level) {

String preStr = "";
for(int i=0; i<level; i++) {
preStr += "    ";
}

File[] childs = f.listFiles();
for(int i=0; i<childs.length; i++) {
System.out.println(preStr + childs[i].getName());
if(childs[i].isDirectory()) {
tree(childs[i], level + 1);
}
}
}

}

为什么我的第一句import java.aa*;会出错。？ 求大神!