在我的应用程序，当我们浏览文件从SD卡的文件将被.text区段，jpg和mpeg4ie视频文件。我想保存每个文件类型到一个特定的文件夹。例如，文件的.text到文本文件夹。我的问题是，当我选择文件，我怎么检查的文件扩展名？

In my application, when we browse the file from sdcard the file will be .text, .jpg and mpeg4ie video file. I want to store each file type into a particular folder. For example, .text files go to the text folder. My question is when I select the file, how do I check the file extension?

推荐答案

我会得到的文件名作为字符串，将其分割成一个数组。作为分隔符，然后拿到阵列，这将是文件扩展名的最后一个索引。例如：

I would get the file name as a String, split it into an array with "." as the delimiter, and then get the last index of the array, which would be the file extension. For example:

public class main {
    public static void main(String[] args) {
        String filename = "image.jpg";
        String filenameArray[] = filename.split("\\.");
        String extension = filenameArray[filenameArray.length-1];
        System.out.println(extension);
    }
}

它输出：

jpg