Java Built-in regular expressions versus Jakarta

Are there any advantages to using the Jakarta regular expression package, over the built-in Java regular expressions?
I wasn't able to find much information on the Jakarta regexp package, except for the Javadoc and I didn't find that very informative.
Thanks!
Jeff

Well, the String.replaceAll(String, String) method uses the Java regexp internally, and I'm not sure there's a way to change that. So that at least is one place that will use it. I don't know for sure, but Jakarta's ORO is supposed to be fully compatible with Perl 5, and also supports other regexp types as well, so if you need that aspect of it, then go with Jakarta. I heard some of Java's are a little limited in some capabilities. I can't find any particular pages that refer to any comparisons of them at to compare runtime performance.

Similar Messages

Java parser for regular expression to java program

Hi All,
I am very new to parser technologies .I am looking for a (java)parser which can read the "regular expression" and can convert it into "java program".Please let me know is there any thing related to this.
Thanks in advance.
Your will be appriciate.
Regards,
Sai.

Hi Jos,
Thank you for your quick response .You're welcome.
If you have any sample code or simple example for how to use those
classes (Pattern,Match) ,will you please send me .It will be helpful for me.Jverd gave you two nice links already in his reply #3
If there is any "open source" for parsering regular expressions.
Please send me I am very new to parser technologies.Note that that Pattern class take care of all the parsing of REs, i.e. there's
nothing 'interesting' left for you to do any parsing whatsoever. Can you
elaborate a bit on what you exactly want to do and learn?
kind regards,
Jos

Java validation with regular expression

Hi
I need to validate a string such that only numbers, alphabets, -, _, . is allowed and the below mentioned code works fine.
if( ! l_name.matches("[A-Za-z0-9._-]+" ) ) {
// do stuff when a valid name is found
But i need to modify the above regex such that it should also allow space in the name. Any idea how to do that?
Thanks in advance.

I tried a space it does not work!!!Then you added the space between a character range or something.
Here, this is a bit more compact:name.matches("[-.\\w\\s]+")

Regular Expressions and XML Schemas

The standard regular expression syntax in JDK1.4 doesn't support some of the constructs used by pattern facets in XML schemas.
For example the "Name" type is specified by the pattern "\i\c*" but the java.util.regex regular expression handler throws an exception when it encounters this with the following message:
Illegal/unsupported escape squence near index 1
Is anyone aware of any regular expression java libraries or tools that will cope with the XML syntax?

Thanks, but perhaps I should clarify. I realise that \i\c* is invalid syntax in the java regexp handler. My point is that in XML Schema regular expressions \i is meaningful - in fact it means
"the set of initial name characters, those matched by Letter | '_' | ':' "
I was wondering if anyone knew of a regular expression library that understood and correctly interpreted that.

Regular Expression Character Sets with Pattern and Matcher

Hi,
I am a little bit confused about a regular expressions I am writing, it works in other languages but not in Java.
The regular expressions is to match LaTeX commands from a file, and is as follows:
\\begin{command}([.|\n\r\s]*)\\end{command}
This does not work in Java but does in PHP, C, etc...
The part that is strange is the . character. If placed as .* it works but if placed as [.]* it doesnt. Does this mean that . cannot be placed in a character range in Java?
Any help very much appreciated.
Kind Regards
Paul Bain

In PHP it seems that the "." still works as a all character operator inside character classes.
The regular expression posted did not work, but it does if I do:
\\begin{command}((.|[\n\r\s])*)?\\end{command}
Basically what I'm trying to match is a block of LaTeX, so the \\begin{command} and \\end{command} in LaTeX, not regex, although the \\ is a single one in LaTeX. I basically want to match any block which starts with one of those and ends in the end command. so really the regular expression that counts is the bit in the middle, ((.|[\n\r\s])*)?
Am I right it saying that the "?" will prevent the engine matching the first and last \\bein and \\end in the following example:
\\begin{command}
some stuff
\\end{command}
\\begin{command}
some stuff
\\end{command}

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.

Using regular expressions in Java SE v1.3.1

Hi,
I have made a package in which I use the regular expressions package in J2SE v1.4. Unfortunately it turned out that my users are only using v1.3. I wonder if it is somehow possible to import the regexp package in v1.3?
Kind regards
Jesper

Sorry No you cant use 1.4.1 RE in 1.3.1
3 ways of getting round this
1)
have 2 diff jar Files, one for 1.3.1 and one for 1.4.1
2)
use a seperate RE package
such as the Java RE package (before it was added in 1.4.1)
or apache's regexp (This is what I do) from
http://jakarta.apache.org/regexp/index.html
3)
tell your users to update to 1.4.1 !!

Regular Expressions (java.util.regex)

I am developing using a product that must
use java 1.2.2_05a but I want to use regular
expressions, does anybody know where I can
get of the package java.util.regex without
having to download the whole java 1.4 release.
Or does someone know of an alternative that
I can use ?

There is another regex pack for java available from Apache Foundation Project. You can try it.
Take a look at http://jakarta.apache.org/

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”
“20111229”
“20B11229”
“A “
“A0111229”
Please note I have also tried \D{1,}+ and \D{1,}? And they also do not return my desired results
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 and Pattern

I have a file that i first want to get all the lines that match a given pattern. Then from these lines that match i want to extract two values.
Example line for the pattern to match
INFO | jvm 1 | 2006/11/07 15:14:09 | INFO | Tue Nov 07 15:14:09 CET 2006 | XLDB PPS Data Dumper: MESSAGE:- 406 Processing .. '[ /opt/nexus/horizon/raw_data/network/pp_CE01S4H_sta_20050703T015717_SYDP3001_546.bdf ]'
So all the lines that are like these i want to extract two variables
2006/11/07 15:14:09
and
/opt/nexus/horizon/raw_data/network/pp_CE01S4H_sta_20050703T015717_SYDP3001_546.bdf
so i can store these variables in a database.
Can someone help me with writing the pattern to match and the regular express to extract? Also if anyone else has a better way of doing this i am all ears and i have a lot of log files to go through.

import java.util.regex.*;
class Main
public static void main(String[] args)
    String txt="INFO | jvm 1 | 2006/11/07 15:14:09 | INFO | Tue Nov 07 15:14:09 CET 2006 | XLDB PPS Data Dumper: MESSAGE:- 406 Processing .. '[ /opt/nexus/horizon/raw_data/network/pp_CE01S4H_sta_20050703T015717_SYDP3001_546.bdf ]'";
    String re1=".*?";     // Non-greedy match on filler
    String re2="((?:2|1)\\d{3}(?:-|\\/)(?:(?:0[1-9])|(?:1[0-2]))(?:-|\\/)(?:(?:0[1-9])|(?:[1-2][0-9])|(?:3[0-1]))(?:T|\\s)(?:(?:[0-1][0-9])|(?:2[0-3])):(?:[0-5][0-9]):(?:[0-5][0-9]))";     // Time Stamp 1
    String re3=".*?";     // Non-greedy match on filler
    String re4="((?:\\/[\\w\\.]+)+)";     // Unix Path 1
    Pattern p = Pattern.compile(re1+re2+re3+re4,Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
    Matcher m = p.matcher(txt);
    if (m.find())
        String timestamp1=m.group(1);
        String unixpath1=m.group(2);
        System.out.print("("+timestamp1.toString()+")"+"("+unixpath1.toString()+")"+"\n");
}

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

Regular expressions with boolean connectives (AND, OR, NOT) in Java?

I'd like to use regular expression patterns that are made up of simple regex patterns connected via AND, OR, or NOT operators, in order to do some keyword-style pattern matching.
A pattern could look like this:
(.*Is there.*) && (.*library.*) && !((.*badword.*) || (^$))
Is there any Java regex library that allows these operators?
I know that in principle these operators should be available, since Regular languages are closed under union, intersection, and complement.

AND is implicit,
xy -- means x AND yThat's not what I need, though, since this is just
concatenation of a regex.
Thus, /xy/ would not match the string "a y a x",
because y precedes x.So it has to contain both x and y, but they could be
in any order?
You can't do that easily or generally.
"x.*y|y.*x" wouldll work here, but obviously
it will get ugly factorially fast as you add more
terms.You got that right: AND means the regex operands can appear in any order.
That's why I'm looking for some regex library that does all this ugly work for me. Again, from a theoretical point of view, it IS possible to express the described semantics of AND with regular expressions, although they will get rather obfuscated.
Unless somebody has done something similar in java (e.g., for C++, there's Ragel: http://www.cs.queensu.ca/~thurston/ragel/) , I will probably use some finite-state-machine libraries and compile the complex regex's into automata (which can be minimized using well-defined operations on FSMs).
>
You'd probably just be better off doing multiple
calls to matches() or whatever. Yes, that's another possibility, do the boolean operators in Java itself.
Of course, if you
really are just looking for literals, then you can
just use str.contains(a) && !str.contains(b) &&
(str.contains(c) || str.contains(d)). You don't
seem to need regex--at least not from your example.OK, bad example, I do have "real" regexp's in there :)

Help with java regular expressions

Hi all ,
i am going to match a patternstring against an input string and print the result here is my code:
     import java.util.regex.*;
     import java.util.*;
     public class Main {
          private static final String CASE_INSENSITIVE = null;
          public static void main(String[] args)
          CharSequence inputStr = "i have 5 years FMCG saLEs exp on java/j2ee and i worked on java and j2ee and 2 projects on telecom java j2ee domain with your with saLEs maNAger experience of java j2ee and c# having very good on c++ exposure in JAVA"
         String patternStr = "\"java j2ee\" and \"c#\"";
          StringTokenizer st = new StringTokenizer(patternStr,"\",OR");
         Matcher matcher=null;
          while(st.hasMoreTokens()){
               String s=st.nextToken();
               Pattern pattern = Pattern.compile(s,Pattern.CASE_INSENSITIVE);
           matcher = pattern.matcher(inputStr);
           while (matcher.find()) {
              String result = matcher.group();
             if(!result.equalsIgnoreCase(" "))
                         System.out.println("result:"+result);
     when i compile this code i am getting the expected result...ie
result:java j2ee
result:java j2ee
result: and
result: and
result: and
result: and
result: and
result: and
result:c#
but when i replace String patternStr = "\"java j2ee\" and \"c#\""; with
String patternStr = "\"java j2ee\" and \"c++\""; i am just getting c in the result instead of c++ ie i am getting result :
result:java j2ee
result:java j2ee
result: and
result: and
result: and
result: and
result: and
result: and
result:C
result:c
result:c
result:c
result:c
result:c
result:c
In the last lines i should get result:c++ instead of result: c
Any ideas please
Thanks

In the last lines i should get result:c++ instead of result: cThe regular expression parser considers the plus sign '+' a special
character; it means: one or more times the previous regular expression.
So 'c++' means one or more 'c's on or more times. Obviously you don't
want that, you want a literal '+' plus sign. You can do that by prepending
the '+' with a backslash '\'. Unfortunately, the javac compiler considers
a backslash a special character and therefore you have to 'escape'
the backslash also, by adding another backslash. The result looks
like this:"c\\+\\+"kind regards,
Jos

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.

Java Built-in regular expressions versus Jakarta

Similar Messages

Maybe you are looking for