Concat在java中的文件中无法正常工作

Question

我必须做一个没有swing库的项目。我必须浏览文件，并尝试执行以下操作：

fichero = new File(fichero.getAbsolutePath().concat("\\" + str));

其中str是要访问的新目录

希望有人能帮助我。 多谢各位

Answer 1

这个

fichero = new File(fichero.getAbsolutePath() + "\\" + str);

或

fichero = new File(fichero.getAbsolutePath() + "/" + str);

或

fichero = new File(fichero.getAbsolutePath().concat("/").concat(str);

应该行得通

Answer 2

您可以使用\\或/。我建议您使用后者，因为它与平台无关

此外，请使用构造函数：

File(String parent, String child)  

文件说：

Creates a new File instance from a parent pathname string and a child pathname string. If parent is null then the new File instance is created as if by invoking the single-argument File constructor on the given child pathname string.

Otherwise the parent pathname string is taken to denote a directory, and the child pathname string is taken to denote either a directory or a file. If the child pathname string is absolute then it is converted into a relative pathname in a system-dependent way. If parent is the empty string then the new File instance is created by converting child into an abstract pathname and resolving the result against a system-dependent default directory. Otherwise each pathname string is converted into an abstract pathname and the child abstract pathname is resolved against the parent.

因此，您的代码应该如下所示：

fichero = new File(fichero.getAbsolutePath(),str);  

NB：您还可以使用接受File和String作为参数的File构造函数，从而消除对getAbsolutePath()的调用