Having this four type of file names:
Filename with double extension
Filename with no extension
Filename with dot at the end, and no extension
Filename with a proper name.
Like this:
String doubleexsension = "doubleexsension.pdf.pdf";
String noextension = "noextension";
String nameWithDot = "nameWithDot.";
String properName = "properName.pdf";
String extension = "pdf";
My aim is to sanitze all the types and output only the filename.filetype properly. I made a little stupid script in order to make this post:
ArrayList<String> app = new ArrayList<String>();
app.add(doubleexsension);
app.add(properName);
app.add(noextension);
app.add(nameWithDot);
System.out.println("------------");
for(String i : app) {
// Ends with .
if (i.endsWith(".")) {
String m = i + extension;
System.out.println(m);
break;
}
// Double extension
String p = i.replaceAll("(\\.\\w+)\\1+$", "$1");
System.out.println(p);
}
This outputs:
------------
doubleexsension.pdf
properName.pdf
noextension
nameWithDot.pdf
I dont know how can I handle the noextension one. How can I do it? When there's no extension, it should take the extension value and apped it to the string at the end.
My desired output would be:
------------
doubleexsension.pdf
properName.pdf
noextension.pdf
nameWithDot.pdf
Thanks in advance.
You may add alternatives to the regex to match all kinds of scenarios:
(?:(\.\w+)\1*|\.|([^.]))$
And replace with $2.pdf. See the regex demo.
EDIT: In case the extensions that can be duplicated are known, you may use the whitelisting approach via an alternation group:
(?:(\.(?:pdf|gif|jpe?g))\1*|\.|([^.]))$
See another regex demo.
Details:
(?: - start of grouping, the $ end of string anchor is applied to all the alternatives below (they must be at the end of string)
(\.\w+)\1* - duplicated (or not) extensions (. + 1+ word chars repeated zero or more times) (with the whitelisting approach, only the indicated extensions will be taken into account - (?:pdf|gif|jpe?g) will only match pdf, gif, jpeg, jpg, etc. if more alternatives are added)
| - or
\. - a dot
| - or
([^.]) - any char that is not a dot captured into Group 2
) - end of the outer grouping
$ - end of string.
See Java demo:
List<String> strs = Arrays.asList("doubleexsension.pdf.pdf","noextension","nameWithDot.","properName.pdf");
for (String str : strs)
System.out.println(str.replaceAll("(?:(\\.\\w+)\\1*|\\.|([^.]))$", "$2.pdf"));
Easy
if (-1 == i.indexOf('.'))
System.out.println(i + "." + extension);
I would avoid the complexity (and reduced readability) of regular expressions:
String m = i;
if (m.endsWith(".")) {
m = m + extension;
}
if (m.endsWith("." + extension + "." + extension)) {
m = m.substring(0, m.length() - extension.length() - 1);
}
if (!m.endsWith("." + extension)) {
m = m + "." + extension;
}
Why so complex. Just do str.replaceAll("\\..*", "") + "." + extension
Java 7 NIO has a way to do this by using PathMatcher
PathMatcher matcher = FileSystems.getDefault().getPathMatcher("glob:*.pdf");
Path filename = namewithdot.pdf;
if (matcher.matches(filename)) {
System.out.println(filename);
}
Related
It may be very simple, but I am extremely new to regex and have a requirement where I need to do some regex matches in a string and extract the number in it. Below is my code with sample i/p and required o/p. I tried to construct the Pattern by referring to https://www.freeformatter.com/java-regex-tester.html, but my regex match itself is returning false.
Pattern pattern = Pattern.compile(".*/(a-b|c-d|e-f)/([0-9])+(#[0-9]?)");
String str = "foo/bar/Samsung-Galaxy/a-b/1"; // need to extract 1.
String str1 = "foo/bar/Samsung-Galaxy/c-d/1#P2";// need to extract 2.
String str2 = "foo.com/Samsung-Galaxy/9090/c-d/69"; // need to extract 69
System.out.println("result " + pattern.matcher(str).matches());
System.out.println("result " + pattern.matcher(str1).matches());
System.out.println("result " + pattern.matcher(str1).matches());
All of above SOPs are returning false. I am using java 8, is there is any way by which in a single statement I can match the pattern and then extract the digit from the string.
I would be great if somebody can point me on how to debug/develop the regex.Please feel free to let me know if something is not clear in my question.
You may use
Pattern pattern = Pattern.compile(".*/(?:a-b|c-d|e-f)/[^/]*?([0-9]+)");
See the regex demo
When used with matches(), the pattern above does not require explicit anchors, ^ and $.
Details
.* - any 0+ chars other than line break chars, as many as possible
/ - the rightmost / that is followed with the subsequent subpatterns
(?:a-b|c-d|e-f) - a non-capturing group matching any of the alternatives inside: a-b, c-d or e-f
/ - a / char
[^/]*? - any chars other than /, as few as possible
([0-9]+) - Group 1: one or more digits.
Java demo:
List<String> strs = Arrays.asList("foo/bar/Samsung-Galaxy/a-b/1","foo/bar/Samsung-Galaxy/c-d/1#P2","foo.com/Samsung-Galaxy/9090/c-d/69");
Pattern pattern = Pattern.compile(".*/(?:a-b|c-d|e-f)/[^/]*?([0-9]+)");
for (String s : strs) {
Matcher m = pattern.matcher(s);
if (m.matches()) {
System.out.println(s + ": \"" + m.group(1) + "\"");
}
}
A replacing approach using the same regex with anchors added:
List<String> strs = Arrays.asList("foo/bar/Samsung-Galaxy/a-b/1","foo/bar/Samsung-Galaxy/c-d/1#P2","foo.com/Samsung-Galaxy/9090/c-d/69");
String pattern = "^.*/(?:a-b|c-d|e-f)/[^/]*?([0-9]+)$";
for (String s : strs) {
System.out.println(s + ": \"" + s.replaceFirst(pattern, "$1") + "\"");
}
See another Java demo.
Output:
foo/bar/Samsung-Galaxy/a-b/1: "1"
foo/bar/Samsung-Galaxy/c-d/1#P2: "2"
foo.com/Samsung-Galaxy/9090/c-d/69: "69"
Because you match always the last number in your regex, I would Like to just use replaceAll with this regex .*?(\d+)$ :
String regex = ".*?(\\d+)$";
String strResult1 = str.replaceAll(regex, "$1");
System.out.println(!strResult1.isEmpty() ? "result " + strResult1 : "no result");
String strResult2 = str1.replaceAll(regex, "$1");
System.out.println(!strResult2.isEmpty() ? "result " + strResult2 : "no result");
String strResult3 = str2.replaceAll(regex, "$1");
System.out.println(!strResult3.isEmpty() ? "result " + strResult3 : "no result");
If the result is empty then you don't have any number.
Outputs
result 1
result 2
result 69
Here is a one-liner using String#replaceAll:
public String getDigits(String input) {
String number = input.replaceAll(".*/(?:a-b|c-d|e-f)/[^/]*?(\\d+)$", "$1");
return number.matches("\\d+") ? number : "no match";
}
System.out.println(getDigits("foo.com/Samsung-Galaxy/9090/c-d/69"));
System.out.println(getDigits("foo/bar/Samsung-Galaxy/a-b/some other text/1"));
System.out.println(getDigits("foo/bar/Samsung-Galaxy/9090/a-b/69ace"));
69
no match
no match
This works on the sample inputs you provided. Note that I added logic which will display no match for the case where ending digits could not be matched fitting your pattern. In the case of a non-match, we would typically be left with the original input string, which would not be all digits.
I have file names separated by colon :
This one is working as expected
String fileName = "test.pdf:test1.txt:test2.png:test3.jpg:test4.jpeg:test5.doc";
String ext = "pdf";
System.out.println(fileName.matches(".*\\b\\."+ext+":\\b.*"));
but when a matching file is at the end, above solution does not work
String fileName = "test1.txt:test2.png:test3.jpg:test4.jpeg:test5.doc:test.pdf";
What is the regex to achieve it?
Change the pattern to look for : or the end $:
".*\\." + ext + "(:|$).*"
(Also, I removed the unnecessary \\b.)
You can use pattern and matcher.
Pattern pdfPattern = Pattern.compile("\\.pdf");
if(pdfPattern.matcher(fileName).find()){
System.out.println("Found PDF");
}
I want to get all .mp4 URLs of this String using Regex.
Also I want to know how to get only the last .mp4 URL using Regex.
Thanks
contentType=application/x-mpegURL, url=https://video.twimg.com/amplify_video/822938952332144642/pl/BjHU8aBCbOgZNzXQ.m3u8},
Variant{bitrate=0, contentType=application/dash+xml, url=https://video.twimg.com/amplify_video/822938952332144642/pl/BjHU8aBCbOgZNzXQ.mpd},
Variant{bitrate=320000, contentType=video/mp4, url=https://video.twimg.com/amplify_video/822938952332144642/vid/320x180/YqZ72rzLj3VWVhy4.mp4},
Variant{bitrate=832000, contentType=video/mp4, url=https://video.twimg.com/amplify_video/822938952332144642/vid/640x360/A2vMgzo2ElpPP6TE.mp4},
Variant{bitrate=2176000, contentType=video/mp4, url=https://video.twimg.com/amplify_video/822938952332144642/vid/1280x720/j9xbNzRZqEbYs_2s.mp4}]}]";
Regex:
https?.*?\.mp4
Literal http
Followed by an optional 's': s?
Remove the question mark if they will all use HTTPS.
Followed by as few characters as possible: .*?
Followed by an mp4 extension (literal dot) \.mp4
2 Approaches:
If you're sure the URL's will always begin with https:// and will not contain a mp4 after the complete URL is finished, then you can use
pattern = "https://.*mp4";
String[] arr = {
"contentType=application/x-mpegURL, url=https://video.twimg.com/amplify_video/822938952332144642/pl/BjHU8aBCbOgZNzXQ.m3u8}",
"Variant{bitrate=0, contentType=application/dash+xml, url=https://video.twimg.com/amplify_video/822938952332144642/pl/BjHU8aBCbOgZNzXQ.mpd}",
"Variant{bitrate=320000, contentType=video/mp4, url=https://video.twimg.com/amplify_video/822938952332144642/vid/320x180/YqZ72rzLj3VWVhy4.mp4}",
"Variant{bitrate=832000, contentType=video/mp4, url=https://video.twimg.com/amplify_video/822938952332144642/vid/640x360/A2vMgzo2ElpPP6TE.mp4}",
"Variant{bitrate=2176000, contentType=video/mp4, url=https://video.twimg.com/amplify_video/822938952332144642/vid/1280x720/j9xbNzRZqEbYs_2s.mp4}]}]"
};
String pattern = "https://.*mp4";
Pattern r = Pattern.compile(pattern);
for (String line : arr) {
Matcher m = r.matcher(line);
if (m.find()) {
System.out.println(m.group(0));
} else {
System.out.println("NO MATCH");
}
}
If not, to Support all types of URL's then change your pattern to what is defined here with a little modification,
String pattern =
"(((ht|f)tp(s?)\\:\\/\\/|~\\/|\\/)|www.)" +
"(\\w+:\\w+#)?(([-\\w]+\\.)+(com|org|net|gov" +
"|mil|biz|info|mobi|name|aero|jobs|museum" +
"|travel|[a-z]{2}))(:[\\d]{1,5})?" +
"(((\\/([-\\w~!$+|.,=]|%[a-f\\d]{2})+)+|\\/)+|\\?|#)?" +
"((\\?([-\\w~!$+|.,*:]|%[a-f\\d{2}])+=?" +
"([-\\w~!$+|.,*:=]|%[a-f\\d]{2})*)" +
"(&(?:[-\\w~!$+|.,*:]|%[a-f\\d{2}])+=?" +
"([-\\w~!$+|.,*:=]|%[a-f\\d]{2})*)*)*" +
"(#([-\\w~!$+|.,*:=]|%[a-f\\d]{2})*)?\\b"+"mp4";
Output:
NO MATCH
NO MATCH
https://video.twimg.com/amplify_video/822938952332144642/vid/320x180/YqZ72rzLj3VWVhy4.mp4
https://video.twimg.com/amplify_video/822938952332144642/vid/640x360/A2vMgzo2ElpPP6TE.mp4
https://video.twimg.com/amplify_video/822938952332144642/vid/1280x720/j9xbNzRZqEbYs_2s.mp4
i have this problem:
i have to make a regular expression which take this urls:
http://www.amazon.it/TP-LINK-TL-WR841N-Wireless-300Mbps-Ethernet/dp/B001FWYGJS?ie=UTF8&redirect=true&ref_=s9_simh_gw_p147_d0_i2
http://www.amazon.it/gp/product/B014KMQWU0/
http://www.amazon.it/gp/product/glance/B014KMQWU0/
I need a regular expression which matches the full url until the ASIN of the product (ASIN is a word of 10 capital letters)
I have write this regex but not make what i want:
String regex="http:\\/\\/(?:www\\.|)amazon\\.com\\/(?:gp\\ product|| gp\\ product\\ glance || [^\\/]+\\/dp|dp)\\/([^\\/]{10})";
Pattern pattern=Pattern.compile(regex);
Matcher urlAmazonMatcher = pattern.matcher(url);
while (urlAmazonMatcher.find()) {
System.out.println("PROVA "+urlAmazonMatcher.group(0));
}
This is my solution. Finally it works :D
String regex="(http|www\\.)amazon\\.(com|it|uk|fr|de)\\/(?:gp\\/product|gp\\/product\\/glance|[^\\/]+\\/dp|dp)\\/([^\\/]{10})";
Pattern pattern=Pattern.compile(regex);
Matcher urlAmazonMatcher = pattern.matcher(url);
String toReturn = null;
while (urlAmazonMatcher.find()) {
toReturn=urlAmazonMatcher.group(0);
}
How about
/[^/?]{10}(/$|\?)
This matches 10 characters that are neither / nor ? following a slash if those characters are followed by a final slash or a question mark.
You can get the part that precedes or follows the ASIN using one of the various Matcher functions.
Here is my work from a previous project that was to extract URLs from text:
private Pattern getUriPattern() {
if(uriPattern == null) {
// taken from http://labs.apache.org/webarch/uri/rfc/rfc3986.html
//TODO implement the full URI syntax
String genDelims = "\\:\\/\\?\\#\\[\\]\\#";
String subDelims = "\\!\\$\\&\\'\\*\\+\\,\\;\\=";
String reserved = genDelims + subDelims;
String unreserved = "\\w\\-\\.\\~"; // i.e. ALPHA / DIGIT / "-" / "." / "_" / "~"
String allowed = reserved + unreserved;
// ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
uriPattern = Pattern.compile("((?:[^\\:/\\?\\#]+:)?//[" + allowed + "&&[^\\?\\#]]*(?:\\?([" + allowed + "&&[^\\#]]*))?(?:\\#[" + allowed + "]*)?).*");
}
return uriPattern;
}
You can use the above method as follows:
Matcher uriMatcher =
getUriPattern().matcher(text);
if(uriMatcher.matches()) {
String candidateUriString = uriMatcher.group(1);
try {
new URI(candidateUriString); // check once again if you matched a URL
// your code here
} catch (Exception e) {
// error handling
}
}
This will catch the whole URL, including params. You can then split it up to the first occurence of '?' (if any) and take the first part. Of course, you can rework the regex too.
I want to replace all :variable (word starting with :) with ${variable}$.
For example,
:aks_num with ${aks_num}$
:brn_num with ${brn_num}$
Following is my code, which does not work:
public static void main(String[] argv) throws Exception
{
CharSequence chSeq = "AND ((:aks_num = -1) OR (aks_num = :aks_num AND ((:brn_num = -1) OR (brn_num = :brn_num))))";
// replaceAll also not working
//String s = chSeq.replaceAll(":\\([a-z_]*\\)","\\${ $1 \\}$");
Pattern p = Pattern.compile(":\\([a-z_]*\\)");
Matcher m = p.matcher(chSeq);
if (m.find()) {
System.out.println("Found value: " + m.group(0) );
System.out.println("Found value: " + m.group(1) );
System.out.println("Found value: " + m.group(2) );
} else {
System.out.println("NO MATCH");
}
}
While in shell script the following regex works perfectly:
s/:\([a-z_]*\)/${\1}$/g
:\\([a-z_]*\\) (with escaped parenthesis) means that you want to match expressions like :(aks_num). Obviously, there are no such expression in the input string. That explains why there are no matches.
Instead, if you want to use parenthesis in order to capture some variables, you should not escape the parenthesis.
Example :
CharSequence chSeq = "AND ((:aks_num = -1) OR (aks_num = :aks_num AND ((:brn_num = -1) OR (brn_num = :brn_num))))";
Pattern p = Pattern.compile(":([a-z_]*)");
Matcher m = p.matcher(chSeq);
while (m.find()) {
System.out.println("Found value: " + m.group(0)+". Captured : "+m.group(1));
}
Output:
Found value: :aks_num. Captured : aks_num
Found value: :aks_num. Captured : aks_num
Found value: :brn_num. Captured : brn_num
Found value: :brn_num. Captured : brn_num
CharSequence chSeq = "AND ((:aks_num = -1) OR (aks_num = :aks_num AND ((:brn_num = -1) OR (brn_num = :brn_num))))";
// replaceAll also not working
//String s = chSeq.replaceAll(":\\([a-z_]*\\)","\\${ $1 \\}$");
Pattern p = Pattern.compile(":(\\w+)");
Matcher m = p.matcher(chSeq);
while (m.find()) {
System.out.println("Found value: " + m.group(1) );
}
Ideone Demo
Working fine with replaceAll
Pattern p = Pattern.compile("(:\\w+)");
Matcher m = p.matcher(x);
x = m.replaceAll("\\${$1}\\$");
You don't need to escape the parentheses, so
Pattern.compile(":([a-z_]*)");
should work.
I believe you got confused with the Java's regex syntax that is different from regular sed syntax. You do not need to escape parentheses to make them "special" grouping operators. Vice versa, in Java, when you escape parentheses, they start matching literal ( and ) symbols.
In the replacement pattern, $ must be escaped for the regex engine to replace with literal $ symbols, but you do not need to escape braces there.
So, just use
.replaceAll(":([a-z_]+)", "\\${$1}\\$")
See the IDEONE demo
I suggest the + quantifier because I doubt you need to match a : followed with a space, or digits - any non-letter.
BTW, you do not need any /g flag in Java since replaceAll will replace all matches with the provided replacement pattern.
NOTE: you can further adjust the pattern to match all letters/digits/underscores with ":(\\w+)". Or just alphanumerics/underscore: ":([\\p{Alnum}_]+)".