Java regular expressions using enum

Hi,
i have created an enum called MONTHS and would like to include it in a pattern. Can somebody give me a hint on how to do that? Should i do it manually (by creating a string like [Jan,Feb...]) or is there a better way?
Thanks

It works by iterating the months and getting a string: months= "Jan|Feb|..." and then appending it to the pattern string. For example:
    public static String getMonthsShortStringList()
        String sList="";
        for (MONTH_SHORT c: MONTH_SHORT.values())
            sList+=c.toString()+'|';
        String newS=sList.substring(0,sList.length()-1);
        return newS;
    }//getMonthsShortStringList
and then...
String months=DateConsts.getMonthsShortStringList(); //get a months disjunctive list
Pattern pattern1=Pattern.compile("("+months+")");
Matcher matcher1=pattern1.matcher((CharSequence)s);
boolean found1=matcher1.find();Is there an alternative to this?

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Logical AND in Java Regular Expressions

I'm trying to implement logical AND using Java Regular Expressions.
I couldn't figure out how to do it after reading Java docs and textbooks. I can do something like "abc.*def", which means that I'm looking for strings which have "abc", then anything, then "def", but it is not "pure" logical AND - I will not find "def.*abc" this way.
Any ideas, how to do it ?
Baken

First off, looks like you're really talking about an "OR", not an "AND" - you want it to match abc.*def OR def.*abc right? If you tried to match abc.*def AND def.*abc nothing would ever match that, as no string can begin with both "abc" and "def", just like no numeric value can be both 2 and 5.
Anyway, maybe regex isn't the right tool for this job. Can you not simply programmatically match it yourself using String methods? You want it to match if the string "starts with" abc and "ends with" def, or vice-versa. Just write some simple code.

Java – Regular Expressions – Finding any non digit byte in a multiple byte

Hello,
I’m new to JAVA and Regular Expressions; I’m trying to write a regular expression that will find any records that contain a non digit byte in a multiple byte field.
I thought the following was the correct expression but it is only finding records that contain “all” non digit bytes.
\D{1,}
\D = Non Digit
{1,} = at least 1 or more
Below is my sample data. I would like the regular expression to find all of the records that are not all numeric. However when I use the regular expression \D{1,} it is only finding the 2 records that all bytes are non digits. (i.e. “ “ and “A “)
“ 111229”
“2 111229”
“20091229”
“200912c9”
“201#1229”
“20101229”
“20110229”
“20111*29”
“20111029”
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“A “
“A0111229”
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Any assistance someone can provide would be greatly appreciated.

You don't show the code you are using but I surmise you are using String.matches() which requires that the whole target must match the regular expression not just part of it. Instead you should create a Pattern and then a Matcher and use the Matcher.find() method. Check the Javadoc for Pattern and Matcher and look at the Java regex tutorial - http://docs.oracle.com/javase/tutorial/essential/regex/ .
P.S. You can re-use the Pattern object - you don't have to create it every time you need one.
P.P.S. Java regular expressions work with characters not bytes and characters are not not not bytes.

Java Regular Expressions in J2EE

Does anybody know when Java Regular Expressions will be available in J2EE. They are currently in the latest release of J2SE in the java.util.regex package.

They are in the Standard Edition, so it does not make sense that they will also be in Enterprise Edition some day. You need to have the standard JRE installed before you can use the J2EE classes anyway.
If you want to use the regular expressions, install version 1.4 (beta) of the J2SE and use the current version of J2EE on top of that.
Jesper

Problems with java regular expressions

Hi everybody,
Could someone please help me sort out an issue with Java regular expressions? I have been using regular expressions in Python for years and I cannot figure out how to do what I am trying to do in Java.
For example, I have this code in java:
import java.util.regex.*;
String text = "abc";
 Pattern p = Pattern.compile("(a)b(c)");
 Matcher m = p.matcher(text);
if (m.matches())
 int count = m.groupCount();
 System.out.println("Groups found " + String.valueOf(count) );
 for (int i = 0; i < count; i++)
 System.out.println("group " + String.valueOf(i) + " " + m.group(i));
My expectation is that group 0 would capture "abc", group 1 - "a" and group 2 - "c". Yet, I I get this:
Groups found 2
group 0 abc
group 1 a
I have tried other patterns and input text but the issue remains the same: no matter what, I cannot capture any paranthesized expression found in the pattern except for the first one. I tried the same example with Jakarta Regexp 1.5 and that works without any problems, I get what I expect.
I am using Java 1.5.0 on Mac OS X 10.4.
Thank to all who can help.

paulcw wrote:
If the group count is X, then there are X plus one groups to go through: 0 for the whole match, then 1 through X for the individual groups.It does seem confusing that the designers chose to exclude the zero-group from group count, but the documentation is clear.
Matcher.groupCount():
Group zero denotes the entire pattern by convention. It is not included in this count.

SQL Injection and Java Regular Expression: How to match words?

Dear friends,
I am handling sql injection attack to our application with java regular expression. I used it to match that if there are malicious characters or key words injected into the parameter value.
The denied characters and key words can be " ' ", " ; ", "insert", "delete" and so on. The expression I write is String pattern_str="('|;|insert|delete)+".
I know it is not correct. It could not be used to only match the whole word insert or delete. Each character in the two words can be matched and it is not what I want. Do you have any idea to only match the whole word?
Thanks,
Ricky
Edited by: Ricky Ru on 28/04/2011 02:29

Avoid dynamic sql, avoid string concatenation and use bind variables and the risk is negligible.

How to define a regular expression using regular expressions

Hi,
I am looking for some regular expression pattern which will identify a regular expression.
Also, is it possible to know how does the compile method of Pattern class in java.util.regex package work when it is given a String containing a regex. ie. is there any mechanism to validate regular expression using regular expression pattern.
Regards,
Abhisek

I am looking for some regular expression pattern which will identify a regular
expression. Also, is it possible to know how does the compile method of
Pattern class in java.util.regex package work when it is given a String
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kind regards,
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Java regular expression for Arabic

i want to use java regular expression to evaluate some string in Arabic
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i have this code :
String poem="��";
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 System.out.print("[" + m.group(j) + "]");
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Exception java.util.regex.PatternSyntaxException: Unknown character property name {?} near index 2
\p?
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Improving Java Regular Expression Compile Time

Hi,
Just wondering if anyone here knows how can i improve the compile time of Java Regular Expression?
The following is fragment of my code which I tired to see the running time.
Calendar rightNow = Calendar.getInstance();
System.out.println("Compile Pattern");
startCompileTime = rightNow.getTimeInMillis();
Pattern p = Pattern.compile(reg, Pattern.CASE_INSENSITIVE);
rightNow = Calendar.getInstance();
endCompileTime = rightNow.getTimeInMillis();
Below is fragment of my regular expression:
(?:tell|state|say|narrate|recount|spin|recite|order|enjoin|assure|ascertain|demonstrate|evidence|distinguish|separate|differentiate|secern|secernate|severalize|tell apart) me (?:about|abou|asti|approximately|close to|just about|some|roughly|more or less|around|or so|almost|most|all but|nearly|near|nigh|virtually|well-nigh) java
My regular expression is a very long one and the Pattern.compile just take too long. The worst case that I experience is 2949342 milliseconds.
Any idea how can I optimise my regular expression so that the compilation time is acceptable.
Thanks in advance

My regular expression is a very long one and the
Pattern.compile just take too long. The worst case
that I experience is 2949342 milliseconds.Wow, that's pretty pathological. I was going to tell you that you were measuring something wrong, because I had written a test program that could compile a 1 Mb "or" pattern (10,000 words, 100 bytes per) in under 200 ms ... but then I noticed that your patterns have two "or" components, so reran my test, and got over 14 seconds to run with a smaller pattern.
My guess is that the RE compiler, rather than decomposing the RE into a tree, is taking the naive approach of translating it into a state machine, and replicating the second component for each path through the first component.
If you can create a simple hand-rolled parser, that may be your best option. However, it appears that your substrings aren't easily tokenized (some include spaces), so your best bet is to break the regexes into pieces at the "or" constructs, and use Pattern.split() to apply each piece sequentially.
import java.util.Random;
import java.util.regex.Pattern;
public class RegexTest
 public static void main(String[] argv) throws Exception
 long initial = System.currentTimeMillis();
 String[] words = generateWords(10000);
// String patStr = buildRePortion(words);
// String patStr = buildRePortion(words) + " xxx ";
 String patStr = buildRePortion(words) + " xxx " + buildRePortion(words);
 long startCompile = System.currentTimeMillis();
 Pattern pattern = Pattern.compile(patStr, Pattern.CASE_INSENSITIVE);
 long finishCompile = System.currentTimeMillis();
 System.out.println("Number of components = " + words.length);
 System.out.println("ms to create pattern = " + (startCompile - initial));
 System.out.println("ms to compile = " + (finishCompile - startCompile));
 private final static String[] generateWords(int numWords)
 String[] results = new String[numWords];
 Random rnd = new Random();
 for (int ii = 0 ; ii < numWords ; ii++)
 char[] word = new char[20];
 for (int zz = 0 ; zz < word.length ; zz++)
 word[zz] = (char)(65 + rnd.nextInt(26));
 results[ii] = new String(word);
 return results;
 private static String buildRePortion(String[] words)
 StringBuffer sb = new StringBuffer("(?:");
 for (int ii = 0 ; ii < words.length ; ii++)
 sb.append(ii > 0 ? "|" : "")
 .append(words[ii]);
 sb.append(")");
 return sb.toString();
}

Java regular expression for CSV?

I found several regular expressions in the internet to parse/split csv data lines. Howeverm, they all don't work with the Java regular expression API. Is there a regular expression to tokenize CSV fields for the Java regexp API?

If the licensing of the above solution is too restrictive for you...I'm sure there are other types of parsers out there that do that type of thing.
In the meantime, here is some code I cooked up (no GPL...use it freely) that might get you started.
Don't know that it handles everything, but I never said it would...
Please READ and let me know what changes could be made. I'm always looking for improvements in my understanding of regular expressions...
import java.util.regex.*;
import java.util.*;
import java.util.List;
public class Example
   final static Pattern CSV_PATTERN;
   final static Pattern DOUBLE_QUOTE;
   static
      String regex = "(?: ([^q;]+) | (?: q ((?: (?:[^q]+) | (?:qq) )+ ) q) );?";
      //                       1          2          a           b       3    4
      // So, pretend your quote character is q
      // (you can change it to \" later when you understand what's going on.)
      // This regex (when applied iteravely) matches a token that:
      // 1) contains NO QUOTE MARKS whatsoever (;'s) (in group 1)
      //                       or
      // 2) starts with a QUOTE, then contains either
      //    a) no quotes at all inside or
      //    b) double quotes (to escape a quote)
      // 3) and ends with a QUOTE.
      // 4) and is followed by a separator (optional for the last value)
      // Note that (a) and (b) are captured in group 2 of the regex.
      CSV_PATTERN = Pattern.compile(regex, Pattern.COMMENTS);
      DOUBLE_QUOTE = Pattern.compile("qq");
    * Attempts to parse Excel CSV stuff...
    * @param text the CSV text.
    * @return a list of tokens.
   public static List parseCsv(String text)
      Matcher csvMatcher = CSV_PATTERN.matcher(text);
      Matcher doubleQuotes = DOUBLE_QUOTE.matcher("");
      List list = new ArrayList();
      while (csvMatcher.find())
         if (csvMatcher.group(1) != null)
            // The first one matched.
            list.add(csvMatcher.group(1));
         else
            doubleQuotes.reset(csvMatcher.group(2));
            list.add(doubleQuotes.replaceAll("q"));
      return list;
}

Perl Regular expression to java Regular Expression

HI all,
How can i write java Regular expression for the below Perl Code
where data.html is my original Html file
and data2.html is output file.
open(FPR, "data.html") || die("Could not open data file");
while ($line=<FPR>) {
$content .= $line;
close(FPR);
open(FPR, ">data2.html") || die("Could not open data2 file");
# clean white spaces
$content =~ s/[\n\r\0 ]//g;
# divide data by td
$rxp='<tr.*?><td.*?>(.*?)<\/.*?td><td.*?>(.*?)<\/.*?td><td.*?>(.*?)<\/.*?td><td.*?>(.*?)<\/.*?td><td.*?>(.*?)<\/.*?td><td.*?>(.*?)<\/.*?td><td.*?>(.*?)<\/.*?td><td.*?>(.*?)<\/.*?td><\/.*?tr>';
while ($content=~ m/$rxp/g)
print FPR "\n".$1."\t".$2."\t".$3."\t".$4."\t".$5."\t".$6."\t".$7."\t".$8."\t";
print FPR " ";
close(FPR);
can you help in this regard
Thanks

I am able to retrive only one row in this format from data.html file
<trvalign=middlebordercolor=#ffffff><tdwidth='40'CLASS='tdbgpricespagecolorgrey'><fontface='Arial,Helvetica,sans-serif'size='2'>SB</td><t
dwidth="23"Class=tdbgpricespagecolorgrey><fontface='Arial,Helvetica,sansserif'size='2'>USAirways</td><tdwidth="34"Class=tdbgpricespagecolorgrey><fontface='Arial,Helvetica,sans-serif'size='2'>MIA</td><tdwidth="31"Class=tdbgpri
cespagecolorgrey><fontface='Arial,Helvetica,sans-erif'size='2'>LGW</td><tdwidth="23"Class=tdbgpricespagecolorgrey><fontface='Arial,Helvetica,sans-serif'size='2'>USAirways</td><tdwidth="34"Class=tdbgpricespagecolorgrey><fontface='Arial,Helvetica,sans-serif'size='2'>LGW</td>
But i need the output in this format
<fontface='Arial,Helvetica,sans-serif'size='2'>SB <fontface='Arial,Helvetica,sans-serif'size='2'>USAirways <fontface='Arial,Helvetica,sans-serif'size='2'>MIA <fontface='Arial,Helvetica,sans-serif'size='2'>LGW <fontface='Arial,Helvetica,sans-serif'size='2'>USAirways <fontface='Arial,Helvetica,sans-serif'size='2'>LGW <fontface='Arial,Helvetica,sans-serif'size='2'>MIA 
<fontface='Arial,Helvetica,sans-serif'size='2'>CS <fontface='Arial,Helvetica,sans-serif'size='2'>USAirways <fontface='Arial,Helvetica,sans-serif'size='2'>MIA <fontface='Arial,Helvetica,sans-serif'size='2'>LON <fontface='Arial,Helvetica,sans-serif'size='2'>USAirways <fontface='Arial,Helvetica,sans-serif'size='2'>LON <fontface='Arial,Helvetica,sans-serif'size='2'>MIA 
How can i rewrite the code to achive this.
Here is my java code
import java.io.*;
import java.util.*;
import java.util.regex.*;
public class parseHTML {
public static void main(String[] args)
try
BufferedReader in = new BufferedReader(new FileReader("C:\\data.html"));
PrintWriter out = new PrintWriter(new FileWriter("C:\\data1.html"));
String aLine = null;
String abc=null;
String pattern1 ="<tr.+?><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td><td.+?>(.+?)</.+?td>++";
Pattern p1 = Pattern.compile(pattern1);
while((aLine = in.readLine()) != null)
abc=aLine.replaceAll("(\n|\t|\r)","").replaceAll(" ","");
Matcher m1 = p1.matcher(abc);
if(m1.find())
System.out.println("the value is...."+m1.group());
out.print(m1.group());
m1.reset(aLine);
in.close();
out.close();
catch(IOException exception)
exception.printStackTrace();
Thanks

Regular Expressions + using them in Vector analysis

Hello,
I would be very glad for any hint concerning this problem:
Consider this ilustrational code sample
import java.util.regex.*;
Vector sequence = new Vector();
 sequence.add("-");
 sequence.add("-");
 sequence.add("A");
 sequence.add("-");
 sequence.add("B");I want to find the first occurence of any alphabetical character ...I thought I can do it like this:
int index = sequence.indexOf("\\w");or from the other point of view like this:
int index = sequence.indexOf("[^-]");Unfortunately none of these are working. Do you know why and how to fix this? There are supposed to be only alphabetical characters and "-" character...
thanks a lot
adam

mAdam wrote:
well, the code I posted above should suit only as an illustration of my problem.
ActualIy I have a bunch of those sequences in an Arraylist...it can be from 5 - 100 sequences(vectors) and I need to use some methods which are available only for Collections (frequency(), insertElementAt()...etc.). I am not a proffesional programmer so I do hope that I am using it correctly instead of "simple" String[][] BunchOfSequences = {seq1,seq2,...}I am not aware of any frequency() or insertElementAt() methods in one of Java's collection classes.
Is it possible to use regular expressions to find a first occurence of a "a-z"(or "A-Z"..it doesnt matter) in a vector then? Or I just need to find it in a "for loop"?
thx
adamRegexes only work on Strings, not on collections holding Strings. So yes, you will need to use a for statement (or similar).
List<String> list = ...
for(String s : list) {
if(s.matches("\\w")) {
}

Regulare Expressions - Uses of logical operators

I need to make use of logical operators within a regulare expression. (greater than, equal, etc.)
It seems to me that java.util.regex.Pattern does not support that kind of expression. First of all: Is this true (If I am wrong with my assumption, how would the expression look like). Secondly: Which library does support this expression?
Thanks in advance!

Regular expressions deal with characters. In that context all characters are 'equal'. You better explain your question a helluva lot better than that.

Java Regular Expression.

I have a document on which i need to extract some information using regular expression. The information needs to be extracted is "Yogi: 123 − 1456". If i created an expression like
(?i)Yogi<filler1><Label=DocumentNumber>(<anynumber>) or
(?i)Yogi<filler1><Label=DocumentNumber>([\d- ]{3,}).. Both expressions doesn't work because the character "−" is a special character. If i just copy paste this sign it works. but when i save my file as xml and try to open this "−"
sign automatically converted as "?". Kindly let me know if any one of you have solution for this.

You better ask this in a Java forum. This forum is about the Small Basic programming language.
Jan [ WhTurner ] The Netherlands

Java Regular Expression to grab html tags

Dear all,
I have written a regular expression in java to grab the pairs of html tags in a String. It worked fine except that it cannot handle space or new line. What have I done wrong?
My regular expression (I would use <tr></tr> as an example):
<tr[^>]*>(.*?)</tr>
It would work for <tr><one>two<three></tr>
but not <tr ><one>two<three></tr>
or <tr> <one> two <three></tr>
or <tr>
<one>two<three>
</tr>
Thanks a lot in advance

I have written a regular expression in java to grab the pairs of html tags in a String. I'll make one last-ditch suggestion that you grab a decent HTML parser, as the HTML specification allows for HTML tags that don't come in pairs. While I'm sure you will be able to eventually write regexes to handle this, it may be easier (depending on your requirements) to use tools to parse the HTML.
Good luck!

Java regular expressions using enum

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