完整代码：https://github.com/tonygeegle/FileTree

private void showTree(File entry, int depth, int order, int brothers) {
    String name = entry.getAbsolutePath();    if (depth > 0) {
        //根据当前节点的深度，打印相应数量的空格进行缩进        for (int i = 1; i < depth; i++) {
            int num = this.indentNum;            // 判断是否打印竖线。这里好像比较复杂，应该进行回溯，单独编写个方法。            
       if (isVerticalLine(entry, i, depth)) {
                System.out.print(this.lines[2]);                num--;            }
            for (int j = 0; j < num; j++) {
                System.out.print(indentChar);            }
        }
        //根据当前节点是否是最后一个节点，打印"└─ "或者"├─ "        
        System.out.print(lines[brothers - order == 0 ? 0: 1]);        
        //根据当前节点的深度，调整打印名字，而不是绝对路径        
       name = entry.getName();    }
        System.out.println(name);    
        if(entry.isDirectory()) {
        File[] children = entry.listFiles(new filter());        
         for (int i = 0; i < children.length; i++) {
            showTree(children[i], depth + 1, i, children.length - 1);        
}
    }
}