File five specify the folder to traverse all files, or recursive writing of specific files

File recursive writing to traverse files

Recursive explanation (picture taken from the Internet):

One: Recursively traverse all types of files

Code:

public class Demo07FileDiGui {
public static void main(String[] args) {
    File file = new File("E:\\xpu\\ideaproject\\20190905\\src\\cn\\itcast\\File");
    digui(file);
}
public static void digui(File dir)
{
    File[] files = dir.listFiles();
    for (File f :
            files) {
        System.out.println(f);
        if(f.isDirectory())//判断是否为文件夹，如果是
            digui(f);//使用递归，继续遍历其中的文件
    }
}
}

Two: Recursively traverse files of the specified type

Code:

public class Demo08FileDiGui2 {
public static void main(String[] args) {
    File file = new File("E:\\xpu\\ideaproject\\20190905\\src\\cn\\itcast\\File");
    digui(file);
}
public static void digui(File dir)
{
    File[] files = dir.listFiles();
    for (File f :
            files) {
        if(f.isDirectory())//判断是否为文件夹，如果是
            digui(f);//使用递归，继续遍历其中的文件
        else {
            String s = f.toString();
            boolean b = s.endsWith(".java");
            if (b)
            System.out.println(f);
        }

    }
}
}

This chapter is the application of the previous learning method