JSP Text Processing with Regex - java

I have a large number (>1500) of JSP files that I am trying to convert to JSPX. I am using a tool that will parse well-formed JSPs and convert to JSPX, however, my JSPs are not all well-formed :)
My solution is to pre-process the JSPs and convert untidy code so the tool will parse them correctly. The main problem I am trying to resolve is that of unquoted attribute values. Examples:
<INPUT id="foo" size=1>
<input id=body size="2">
My current regex for finding these is (in Java string format):
"(\\w+)=([^\"' >]+)"
And my replacement string is (in Java string format):
"$1=\"$2\""
This works well, EXCEPT for a few patterns, both of which involve inline scriptlets. For example:
<INPUT id=foo value="<%= someBean.method("a=b") %>">
In this case, my pattern matches the string literal "a=b", which I don't want to do. What I'd like to have happen is that the regex would IGNORE anything between <% and %>. Is there a regular expression that will do what I am trying to do?
EDIT:
Changed to title to clarify that I am NOT trying to parse HTML / JSP with regexes... I am doing a simple syntactic transformation to prepare the input for parsing.

If a sentence contains an arbitrary number of matching tokens such as double quotes, then this sentence belongs to a context-free language, which simply cannot be parsed with Regex designed to handle regular languages.
Either there could be some simplification assumptions (e.g. there are no unmatched double quotes and there is only a certain number of those etc.) that would permit the use of Regex, or your need to think about using (creating) a lexer/parser for a case of context-free language. ANTLR is a good tool for this.

Based on the assumption that there are NO unquoted attribute values inside the scriptlets, the following construct might work for you:
Note: this approach is fragile. Just for your reference.
import java.util.regex.*;
public class test{
public static void main(String args[]){
String s = "<INPUT id=foo abbr='ip ' name = bar color =\"blue\" value=\" <%= someBean.method(\" a = b \") %>\" nickname =box >";
Pattern p = Pattern.compile("(\\w+)\\s*=\\s*(\\w+[^\"'\\s])");
Matcher m = p.matcher(s);
while (m.find())
{
System.out.println("Return Value :"+m.group(1)+"="+m.group(2));
}
}
}
Output:
Return Value:id=foo
Return Value:name=bar
Return Value:nickname=box

Related

How to insert HTML code in a context variable with thyme leaf [duplicate]

I'm using Thymeleaf to process html templates, I understood how to append inline strings from my controller, but now I want to append a fragment of HTML code into the page.
For example, lets stay that I have this in my Java application:
String n="<span><i class=\"icon-leaf\"></i>"+str+"</span> \n";
final WebContext ctx = new WebContext(request, response,
servletContext, request.getLocale());
ctx.setVariable("n", n);
What do I need to write in the HTML page so that it would be replaced by the value of the n variable and be processed as HTML code instead of it being encoded as text?
You can use th:utext attribute that stands for unescaped text (see documentation). Use this with caution and avoid user input in th:utext as it can cause security problems.
<div th:remove="tag" th:utext="${n}"></div>
If you want short-hand syntax you can use following:
[(${variable})]
Escaped short-hand syntax is
[[${variable}]]
but if you change inner square brackets [ with regular ( ones HTML is not escaped.
Example within tags:
<div>
[(${variable})]
</div>

Regex pattern to identify attribute value

I have a source code file which I am trying to read using a automatic Regex processor Class in java.
Although I am unable to form a correct regex pattern to get the values if it appears multiple times in the line.
The input text is:
<input name="id" type="radio" bgcolor="<bean:write name='color'/>" value="<bean:write name='nameProp' property='nameVal'/>" <logic:equal name="checkedStatus" value="0">checked</logic:equal>>
And I want the matcher.find to output following terms:
<bean:write name='color'/>
<bean:write name='nameProp' property='nameVal'/>
Kindly help to form the regex pattern for this scenario.
Use this regex to find those terms:
<bean:write[^\/]*\/>
It will search for the words <bean:write and then everything up until a />
Use it like this:
List<String> matches = new ArrayList<>();
Matcher m = Pattern.compile("<bean:write[^\\/]*\\/>")
.matcher(inputText);
while (m.find()) {
matches.add(m.group());
}
Regex101 Tested
I caution you though with parsing HTML with regex. If you need anything more complicated than this, you should probably consider using an XML parser instead. See this famous answer.

java HTML regexp issue

I am trying to transform the following string:
<img src="image.jpg" ... />
with this one
<img src="cid:image" ... />
the "image" string needs to be maintained but the string itself could be different. In the html document there are different img tags each one with a different image file.
so for instance if I have:
<img src="mylogo.jpg" ... />
it should transform to:
<img src="cid:mylogo" ... />
The images could be jpg or gif.
Thanks for any help,
Note:
Apart from the fact that Regex is not the right tool to parse HTML, as mentioned in comments, because in Java there are many tools for parsing HTML maybe you can take a look at jsoup for example, I will give you a solution that fits your needs of using Regex.
Solution:
You can use the following Regex:
src=\"([\\:\\w\\s\\/]+)\\.\\w{3}\"
This is the code you need:
String html = "<img src=\"folder1/mylogo.jpg\" ... />";
Pattern pattern = Pattern.compile("src=\"([\\:\\w\\s\\/]+)\\.\\w{3}\"");
Matcher matcher = pattern.matcher(html);
while (matcher.find()) {
System.out.println("group 1: " + matcher.group(1));
//This line will give you the wanted output.
System.out.println("src=\"cid:"+matcher.group(1)+"\"");
System.out.println("Final Result: "+html.replaceAll("src=\"([\\:\\w\\s\\/]+)\\.\\w{3}\"", "src=\"cid:$1\""));
}
And this is a Working DEMO.
Explanation:
src= matches the characters src= literally.
\" matches the character " literally.
([\\w\\/]+) is a capturing group to match all the wanted text.
\. matches the character . literally.
\w{3,4} match any word character [a-zA-Z0-9_] between 3 and 4 times for extensions, you can use jpg|gif instead if you are not willing to use any other image extensins.
\" matches the character " literally
EDIT:
Desired output:
And to replace this expression with the wanted result just use this regex on the replaceAll() method with your HTML, as follow:
html.replaceAll("src=\"([\\:\\w\\s\\/]+)\\.\\w{3}\"", "src=\"cid:$1\"");
We use $1 to point to the first capturing group.

how to match string using regular expression

I have a string which contains multiple occurrences of the "<p class=a> ... </p>" where ... is different text.
I am using "<p class=a>(.*)</p>" regex pattern to split the text into chunks. but this is not working. what would be the correct regex for this?
P.S. the same regex pattern is working in iOS using NSRegularExpression but not working in android using Pattern.
To explain my problem more : i am doing the following
Pattern regex3 = Pattern.compile("(?s)<P Class=ENCC>(.*?)</P>", CASE_INSENSITIVE);
String[] result = p.split(str);
result array contains only 1 item and it is the whole string
and the following is a portion of the file that i am reading :
<BODY>
<SYNC Start=200>
<P Class=ENCC><i>Cerita, Watak, Adegan dalam</i><br/><i>Drama Ini Rekaan Semata-Mata.</i></P>
</SYNC>
<SYNC Start=2440>
<P Class=ENCC> </P>
</SYNC>
<SYNC Start=2560>
<P Class=ENCC><i>Kami Tidak Berniat</i><br/><i>Melukakan Hati Sesiapa.</i></P>
</SYNC>
<SYNC Start=4560>
<P Class=ENCC> </P>
</SYNC>
<SYNC Start=66160>
<P Class=ENCC>Hai kawan-kawan.<br/>Inilah bandaraya Banting.</P>
</SYNC>
UPDATE ::::
hi everybody, I have got the problem. the problem was actually with the encoding of the file that i was reading. the file was UTF-16 (Little Endian) encoded. that was causing the all problem of regex not working. i changed it to UTF-8 and everything started working .. thanx everybody for your support.
Parsing HTML with regular expressions is not really a good idea (reason here). What you should use in an HTML parser such as this.
That being said, your issue is most likely the fact that the * operator is greedy. In your question you just say that it is not working, so I think that your problem is because it is matching the first <p class=a> and the very last </p>. Making the regular expression non greedy, like so: <p class=a>(.*?)</p> (notice the extra ? to make the * operator non greedy) should solve the problem (assuming that your problem is the one I have stated earlier).
That being said, I would really recommend you ditch the regular expression approach and use appropriate HTML Parsers.
EDIT:
Now that you've posted the code and the text you're matching against, one thing immediately leaps to mind:
You're matching <p class..., but your string contains <P Class.... Regexes are case-sensitive.
Then, . does not match newlines. And it's quite likely that your paragraphs do contain newlines.
Therefore, try "(?si)<p class=a>(.*?)</p>". The (?s) modifier allows the dot to match newlines, too, and the (?i) modifier makes the regex case-insensitive.
The .* may match <. You can try :
<p class=a>([^<]*)</p>
I guess the problem is that your pattern is greedy. You should use this instead.
"<p class=a>(.*?)</p>"
If you have this string:
"<p class=a>fist</p><p class=a>second</p>"
Your pattern ("<p class=a>(.*)</p>") will match this
"<p class=a>fist</p><p class=a>second</p>"
While "<p class=a>(.*?)</p>" only matches
"<p class=a>fist</p>"

Using regex, how to change the attribute values from one pattern to another

I have a html file in which the html elements have name as follows :
<input type="text" name="HCFA_DETAIL_SUPPLEMENTAL" value="" size="64" />
My requirement is to rename the name attribute value in java naming convention as follows :
<input type="text" name="hcfaDetailSupplemental" value="" size="64" />
Since there are large number of such elements, I want to accomplish that using regex. Can anyone suggest my how to achieve that using regex ?
Do not use regular expressions to go over HTML (why here). Using an appropriate framework such as HTML Parser should do the trick.
A series of samples to get you started are available here.
Using jQuery to get the name, and then regexes to replace all the _[a-z] occurances:
$('input').each(function () {
var s = $(this).attr('name').toLowerCase();
while (s.match("_[a-z]"))
s = s.replace(new RegExp("_[a-z]"), s.match("_[a-z]").toString().toUpperCase());
$(this).attr('name', s);
});
In most cases using regex with html is bad practice, but if you must use it, then here is one of solutions.
So first you can find text in name="XXX" attribute. It can be done by using this regex (?<=name=")[a-zA-Z_]+(?="). When you find it, replace "_" by "" and don't forget to lowercase rest of letters. Now you can replace old value by new one using same regex we used before.
This should do the trick
String html="<input type=\"text\" name=\"HCFA_DETAIL_SUPPLEMENTAL\" value=\"\" size=\"64\"/>";
String reg="(?<=name=\")[a-zA-Z_]+(?=\")";
Pattern pattern=Pattern.compile(reg);
Matcher matcher=pattern.matcher(html);
if (matcher.find()){
String newName=matcher.group(0);
//System.out.println(newName);
newName=newName.toLowerCase().replaceAll("_", "");
//System.out.println(newName);
html=html.replaceFirst(reg, newName);
}
System.out.println(html);
//out -> <input type="text" name="hcfadetailsupplemental" value="" size="64"/>

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