java：在目录和子目录中根据文件名搜索文件

我需要根据目录树中的名称查找文件。然后显示该文件的路径。我发现了类似的东西，但它根据扩展名进行搜索。谁能帮助我如何根据我的需要重新编写这段代码...谢谢

public class filesFinder {
public static void main(String[] args) {
    File root = new File("c:\\test");

    try {
        String[] extensions = {"txt"};
        boolean recursive = true;


        Collection files = FileUtils.listFiles(root, extensions, recursive);

        for (Iterator iterator = files.iterator(); iterator.hasNext();) {
            File file = (File) iterator.next();
            System.out.println(file.getAbsolutePath());
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}
}

public class Test {
    public static void main(String[] args) {
        File root = new File("c:\\test");
        String fileName = "a.txt";
        try {
            boolean recursive = true;

            Collection files = FileUtils.listFiles(root, null, recursive);

            for (Iterator iterator = files.iterator(); iterator.hasNext();) {
                File file = (File) iterator.next();
                if (file.getName().equals(fileName))
                    System.out.println(file.getAbsolutePath());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}