Java - 创建新文件，如何使用方法指定目录？

我知道如何通过以下方式将文件写入指定的目录：

I know how to write a file to a specified directory by doing this:

 public void writefile(){

    try{
        Writer output = null;
        File file = new File("C:\\results\\results.txt");
        output = new BufferedWriter(new FileWriter(file));

        for(int i=0; i<100; i++){
           //CODE TO FETCH RESULTS AND WRITE FILE
        }

        output.close();
        System.out.println("File has been written");

    }catch(Exception e){
        System.out.println("Could not create file");
    }

但是，如果目录设置在一个方法？一个名为 getCacheDirectory（）的方法。假设所有必要的导入等都已经完成了。

But how do I go on specifying the directory, if the directory is set in a method? A method called getCacheDirectory() for example. Assuming that all necessary imports etc have been done..

谢谢：）。