Trong java, bạn có thể implements giao tiếp FilenameFilter và override phương thức accept(File dir, String name) để filter file theo phần mở rộng.
Ví dụ 1: implement giao tiếp FilenameFilter để liệt kê ra các file có phần mở rộng là ".txt", sau đó thực hiện xóa từng file.
import java.io.File;
import java.io.FilenameFilter;
public class DeleteFilesExample {
private static final String FILE_DIR = "D:\\log";
private static final String FILE_TEXT_EXT = ".txt";
public static void main(String args[]) {
new DeleteFilesExample().deleteFile(FILE_DIR, FILE_TEXT_EXT);
}
public void deleteFile(String folder, String ext) {
GenericExtFilter filter = new GenericExtFilter(ext);
File dir = new File(folder);
// list out all the file name with .txt extension
String[] list = dir.list(filter);
// delete files
if (list.length == 0) {
File fileDelete;
for (String file : list) {
String temp = new StringBuffer(FILE_DIR).append(File.separator).append(file).toString();
fileDelete = new File(temp);
boolean isdeleted = fileDelete.delete();
System.out.println("file : " + temp + " is deleted : " + isdeleted);
}
}
}
// inner class, generic extension filter
public class GenericExtFilter implements FilenameFilter {
private String ext;
public GenericExtFilter(String ext) {
this.ext = ext;
}
public boolean accept(File dir, String name) {
return (name.endsWith(ext));
}
}
}
Giả sử trong folder log có chứa các file: a.txt, b,txt, c.txt, d.txt:
Output:
file : D:\log\a.txt is deleted : true file : D:\log\b.txt is deleted : true file : D:\log\c.txt is deleted : true file : D:\log\d.txt is deleted : true
Ví dụ 2, Delete nhiều file trong java sử dụng lớp nặc danh
import java.io.File;
import java.io.FilenameFilter;
public class DeleteFilesExample2 {
private static final String FILE_DIR = "D:\\log";
private static final String FILE_TEXT_EXT = ".txt";
public static void deleteFiles(String folder, String ext) {
File dir = new File(folder);
// list out all the file name with .txt extension
String[] list = dir.list(new FilenameFilter() {
@Override
public boolean accept(File file, String name) {
return name.endsWith(FILE_TEXT_EXT);
}
});
// delete files
if (list.length == 0) {
File fileDelete;
for (String file : list) {
String temp = new StringBuffer(FILE_DIR).append(File.separator).append(file).toString();
fileDelete = new File(temp);
boolean isdeleted = fileDelete.delete();
System.out.println("file : " + temp + " is deleted : " + isdeleted);
}
}
}
}
Giả sử trong folder log có chứa các file: a.txt, b,txt, c.txt, d.txt:
Output:
file : D:\log\a.txt is deleted : true file : D:\log\b.txt is deleted : true file : D:\log\c.txt is deleted : true file : D:\log\d.txt is deleted : true