Ignore parameters in url using regex in java - java

So I have the following route /path1/path2/{value1}/path3/{value2} and I'm trying to figure out if the request route matches path1 path2 and path3 regardless the {value1} and {value2} which change.
This is what I have but its not matching:
#Test
public void testURLMatches() {
String input = "/path1/path2/123/path3/456";
Pattern pattern = Pattern.compile("\\/path1\\/path2\\/([a-zA-Z0-9]{0,})\\/path3\\/([a-zA-Z0-9]{0,})");
Matcher matcher = pattern.matcher(input);
if (matcher.find()) {
System.out.println("Does match!");
} else {
System.out.println("Does not match!");
}
assertTrue(matcher.find());
}
Edit 1:
Added in the pattern \/ which was missing originally

I think the Regex you are looking at is
^\/path1\/path2\/([\w]+)\/path3\/([\w]+)$
PS : You have another problem in your test, you call the matcher.find() functions twice, whereas you should only call it once. Remove the if condition.
In Java, you get
#Test
public void testURLMatches() {
String input = "/path1/path2/123/path3/456";
Pattern pattern = Pattern.compile("^\\/path1\\/path2\\/([\\w]+)\\/path3\\/([\\w]+)$");
Matcher matcher = pattern.matcher(input);
assertTrue(matcher.find());
}
(example)

Your pattern does not match because you need a / after: /path2, try this and it will work:
string input = "/path1/path2/123/path3/456";
string pattern = #"\/path1\/path2\/[a-zA-Z0-9]{0,}\/path3\/[a-zA-Z0-9]{0,}";
Match m = Regex.Match(input, pattern, RegexOptions.IgnoreCase);
if (m.Success)
{
// match
}
else
{
// not match
}
It is not very clear for me what is the accepted values for {Value}, but you can use this, as well:
\/path1\/path2\/[\w]*\/path3\/[\w]*
[\w]*: zero or more occurrence of any alphanumeric char

Related

matches.find() with replaceAll()

I am new to Java and I found a loop in existing code that seems like it should be an infinite loop (or otherwise have highly undesirable behavior) which actually works.
Can you explain what I'm missing? The reason I think it should be infinite is that according to the documentation here (https://docs.oracle.com/javase/8/docs/api/java/util/regex/Matcher.html#replaceAll-java.lang.String-) a call to replaceAll will reset the matcher (This method first resets this matcher. It then scans the input sequence...). So I thought the below code would do its replacement and then call find() again, which would start over at the beginning. And it would keep finding the same string, since as you can see the string is just getting wrapped in a tag.
In case it's not obvious, Pattern and Matcher are the classes in java.util.regex.
String aTagName = getSomeTagName()
String text = getSomeText()
Pattern pattern = getSomePattern()
Matcher matches = pattern.matcher(text);
while (matches.find()) {
text = matches.replaceAll(String.format("<%1$s> %2$s </%1$s>", aTagName, matches.group()));
}
Why is that not the case?
I share your suspicions that this code very likely is unintended, for replaceAll changes the state, and since it scans the string to replace, the result is that only 1 search is performed and stated group is used to replace all searches with this group.
String text = "abcdEfg";
Pattern pattern = Pattern.compile("[a-z]");
Matcher matches = pattern.matcher(text);
while (matches.find()) {
System.out.println(text); // abcdEfg
text = matches.replaceAll(matches.group());
System.out.println(text); // aaaaEaa
}
As replaceAll tells the matcher to scan through the string, it ends up moving the pointer to the end to exhaust the entire string's state. Then find resumes search (from the current state - which is the end, not the start), but the search has already been exhausted.
One of the correct ways to iterate and replace for each group appropriately may be to use appendReplacement:
String text = "abcdEfg";
Pattern pattern = Pattern.compile("[a-z]");
Matcher matches = pattern.matcher(text);
StringBuffer sb = new StringBuffer();
while (matches.find()) {
matches.appendReplacement(sb, matches.group().toUpperCase());
System.out.println(text); // some of ABCDEFG
}
matches.appendTail(sb);
System.out.println(sb); // ABCDEFG
The below examples shows there is no reason to call the while loop if you are using replace all. In both the cases the answer is
is th is a summer ? Th is is very hot summer. is n't it?
import java.util.regex.*;
public class Test {
public static void main(String[] args) {
String text = "is this a summer ? This is very hot summer. isn't it?";
String tag = "b";
String pattern = "is";
System.out.println(question(text,tag,pattern));
System.out.println(alt(text,tag,pattern));
}
public static String question(String text, String tag, String p) {
Pattern pattern = Pattern.compile(p);
Matcher matcher= pattern.matcher(text);
while (matcher.find()) {
text = matcher.replaceAll(
String.format("<%1$s> %2$s </%1$s>",
tag, matcher.group()));
}
return text;
}
public static String alt(String text, String tag, String p) {
Pattern pattern = Pattern.compile(p);
Matcher matcher= pattern.matcher(text);
if(matcher.find())
return matcher.replaceAll(
String.format("<%1$s> %2$s </%1$s>",
tag, matcher.group()));
else
return text;
}
}

text wrongly matchs with sub string of words in group

I want to check the text to see if it starts with what or who and and is a question type, so for that I wrote the following code:
private static void startWithQOrIf(String commentstr){
String urlPattern = "(|who|what).*\\?.*$";
Pattern p = Pattern.compile(urlPattern,Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher(commentstr);
if (m.find()) {
System.out.println("yes");
}
}
everything works good but for example when I try:
whooooooooo is the follower?
will match as well but should not because I am looking for who not whooooooooo
Any idea?
You can ensure a whole word using a word boundary \b:
(|who|what)\\b.*\\?.*$
^^
If the words in the alternation group are supposed to appear at the start of the string, you can just use matches and remove $ anchor:
String urlPattern = "(|who|what)\\b.*\\?.*";
Pattern p = Pattern.compile(urlPattern,Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher(commentstr);
if (m.matches()) { // < - Here, matches is used
System.out.println("yes");
}
Note that (|who|what) matches either an empty string, or who, or what. If you do not plan to allow empty string, use just (who|what).
You must use word boundaries.
String urlPattern = "\\b(who|what)\\b.*\\?.*$";

Finding Upper Case in String Array and extracting it out

I have an array input like this which is an email id in reverse order along with some data:
MOC.OOHAY#ABC.PQRqwertySDdd
MOC.OOHAY#AB.JKLasDDbfn
MOC.OOHAY#XZ.JKGposDDbfn
I want my output to come as
MOC.OOHAY#ABC.PQR
MOC.OOHAY#AB.JKL
MOC.OOHAY#XZ.JKG
How should I filter the string since there is no pattern?
There is a pattern, and that is any upper case character which is followed either by another upper case letter, a period or else the # character.
Translated, this would become something like this:
String[] input = new String[]{"MOC.OOHAY#ABC.PQRqwertySDdd","MOC.OOHAY#AB.JKLasDDbfn" , "MOC.OOHAY#XZ.JKGposDDbfn"};
Pattern p = Pattern.compile("([A-Z.]+#[A-Z.]+)");
for(String string : input)
{
Matcher matcher = p.matcher(string);
if(matcher.find())
System.out.println(matcher.group(1));
}
Yields:
MOC.OOHAY#ABC.PQR
MOC.OOHAY#AB.JKL
MOC.OOHAY#XZ.JKG
Why do you think there is no pattern?
You clearly want to get the string till you find a lowercase letter.
You can use the regex (^[^a-z]+) to match it and extract.
Regex Demo
Simply split on [a-z], with limit 2:
String s1 = "MOC.OOHAY#ABC.PQRqwertySDdd";
String s2 = "MOC.OOHAY#AB.JKLasDDbfn";
String s3 = "MOC.OOHAY#XZ.JKGposDDbfn";
System.out.println(s1.split("[a-z]", 2)[0]);
System.out.println(s2.split("[a-z]", 2)[0]);
System.out.println(s3.split("[a-z]", 2)[0]);
Demo.
You can do it like this:
String arr[] = { "MOC.OOHAY#ABC.PQRqwertySDdd", "MOC.OOHAY#AB.JKLasDDbfn", "MOC.OOHAY#XZ.JKGposDDbfn" };
for (String test : arr) {
Pattern p = Pattern.compile("[A-Z]*\\.[A-Z]*#[A-Z]*\\.[A-Z.]*");
Matcher m = p.matcher(test);
if (m.find()) {
System.out.println(m.group());
}
}

Print out the last match of a regex

I have this code:
String responseData = "http://xxxxx-f.frehd.net/i/world/open/20150426/1370235-005A/EPISOD-1370235-005A-016f1729028090bf_,892,144,252,360,540,1584,2700,.mp4.csmil/.m3u8";
"http://xxxxx-f.frehd.net/i/world/open/20150426/1370235-005A/EPISOD-1370235-005A-016f1729028090bf_,892,144,252,360,540,1584,2700,.mp4.csmil/.m3u8";
String pattern = ^(https://.*\.54325)$;
Pattern pr = Pattern.compile(pattern);
Matcher math = pr.matcher(responseData);
if (math.find()) {
// print the url
}
else {
System.out.println("No Math");
}
I want to print out the last string that starts with http and ends with .m3u8. How do I do this? I'm stuck. All help is appreciated.
The problem I have now is that when I find a math and what to print out the string, I get everything from responseData.
In case you need to get some substring at the end that is preceded by similar substrings, you need to make sure the regex engine has already consumed as many characters before your required match as possible.
Also, you have a ^ in your pattern that means beginning of a string. Thus, it starts matching from the very beginning.
You can achieve what you want with just lastIndexOf and substring:
System.out.println(str.substring(str.lastIndexOf("http://")));
Or, if you need a regex, you'll need to use
String pattern = ".*(http://.*?\\.m3u8)$";
and use math.group(1) to print the value.
Sample code:
import java.util.regex.*;
public class HelloWorld{
public static void main(String []args){
String str = "http://xxxxx-f.akamaihd.net/i/world/open/20150426/1370235-005A/EPISOD-1370235-005A-016f1729028090bf_,892,144,252,360,540,1584,2700,.mp4.csmil/index_0_av.m3u8" +
"EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2795000,RESOLUTION=1280x720,CODECS=avc1.64001f, mp4a.40.2" +
"http://xxxxx-f.akamaihd.net/i/world/open/20150426/1370235-005A/EPISOD-1370235-005A-016f1729028090bf_,892,144,252,360,540,1584,2700,.mp4.csmil/index_6_av.m3u8";
String rx = ".*(http://.*?\\.m3u8)$";
Pattern ptrn = Pattern.compile(rx);
Matcher m = ptrn.matcher(str);
while (m.find()) {
System.out.println(m.group(1));
}
}
}
Output:
http://xxxxx-f.akamaihd.net/i/world/open/20150426/1370235-005A/EPISOD-1370235-005A-016f1729028090bf_,892,144,252,360,540,1584,2700,.mp4.csmil/index_6_av.m3u8
Also tested on RegexPlanet

Java Pattern matching regex

I am doing a Pattern match the matcher.matches is coming as false, while the matcher.replaceAll actually finds the pattern and replaces it. Also the matcher.group(1) is returning an exception.
#Test
public void testname() throws Exception {
Pattern p = Pattern.compile("<DOCUMENT>(.*)</DOCUMENT>");
Matcher m = p.matcher("<RESPONSE><DOCUMENT>SDFS878SDF87DSF</DOCUMENT></RESPONSE>");
System.out.println("Why is this false=" + m.matches());
String s = m.replaceAll("HEY");
System.out.println("But replaceAll found it="+s);
}
I need the matcher.matches() to return true, and the matcher.group(1) to return
"<DOCUMENT>SDFS878SDF87DSF</DOCUMENT>"
Thanks in advance for the help.
final Pattern pattern = Pattern.compile("<DOCUMENT>(.+?)</DOCUMENT>");
final Matcher matcher = pattern.matcher("<RESPONSE><DOCUMENT>SDFS878SDF87DSF</DOCUMENT></RESPONSE>");
if (matcher.find())
{
System.out.println(matcher.group(1));
// code to replace and inject new value between the <DOCUMENT> tags
}

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