The regex required is quite simple.
myfile_.*_[123]\\.mp4
Frage
Suppose I have files like these in a folder:
How do I find files where only the names containing "myfile_" in the prefix and suffix would be 3 or less("_3.mp4", "_2.mp4", "_1.mp4", something like this).
So in my program I could get:
I have tried this one, hoping to get lucky but I didn't get any result. :D
String myDirectory = Environment.getExternalStorageDirectory().getAbsolutePath();
File f = new File(myDirectory);
if (f.exists() && f.isDirectory()){
final Pattern p = Pattern.compile("myfile_*\\_(^0*(1?\\d|%d)$).mp4"); // I know I really have a stupid mistake on the regex;
File[] flists = f.listFiles(new FileFilter(){
@Override
public boolean accept(File file) {
return p.matcher(file.getName()).matches();
}
});
String s = "wait a minute, i'm debugging";
}
I hope someone can help out on my problem.
Lösung
The regex required is quite simple.
myfile_.*_[123]\\.mp4
Andere Tipps
try this :-
String myDirectory = Environment
.getExternalStorageDirectory().getAbsolutePath();
File f = new File(myDirectory);
if (f.exists() && f.isDirectory()) {
final Pattern p = Pattern.compile("yourfile_.*_[123]\\.png");
File[] flists = f.listFiles(new FileFilter() {
@Override
public boolean accept(File file) {
p.matcher(file.getName()).matches();
Log.e("MIS", "sdsdsdsds" + p.matcher(file.getName()).matches());
return p.matcher(file.getName()).matches();
}
});
String s = "wait a minute, i'm debugging";
}
If you want to do this with a Pattern
, here's a working example, since the Pattern
you use has many issues.
String mark = "myfile_mark_1.mp4";
String john = "myfile_john_2.mp4";
String jake = "myfile_jake_3.mp4";
Pattern pattern = Pattern.compile("myfile_\\p{Alpha}+_\\d+\\.mp4");
Matcher matcher = pattern.matcher(mark);
System.out.println(matcher.find());
matcher = pattern.matcher(john);
System.out.println(matcher.find());
matcher = pattern.matcher(jake);
System.out.println(matcher.find());
Output:
true
true
true
Issues I found in the Pattern
you use:
^0
part as an optional starting character. The ^
character can mean the beginning of the whole input, or the negation of a character or group (which only works in character classes). .
in your Pattern
must be escaped. %d
means in your Pattern
, as it doesn't reflect anything in your examples. Is it because you want to group the numbers and back-reference them? In that case, you can wrap your numerical expression around round brackets - it'll be your index-1 group in this case. Try some thing like this. I think it is easy
String fileName="myfile_mark_1.mp4";
if(fileName.startsWith("myfile")){
if(Integer.parseInt(fileName.split("_")[2].substring(0,1))<=3){
System.out.println(fileName);
}
}
Following will return all files in your computer match with your criteria.
public static void main(String[] args) {
File[] paths = File.listRoots();
for(File directory:paths){
getFile(directory.toString());
}
}
public static void getFile(String directoryName) {
File directory = new File(directoryName);
File[] fList = directory.listFiles();
if(fList!=null){
for (File file : fList) {
if (file.isFile()) {
if(file.getName().toString().startsWith("myfile")){
if(Integer.parseInt(file.getName().toString().split("_")[2].substring(0,1))<=3){
System.out.println(file.getName().toString());
}
}
} else if (file.isDirectory()) {
getFile(file.getAbsolutePath());
}
}
}
}