CODEWITHSUNDEEP
javaphpregex
TonyCruze
TonyCruze

Reputation: 430

Using Regex in Java based on working php code

I've been using this in php...

preg_match_all('|<a href="http://www.example.com/photoid/(.*?)"><img src="(.*?)" alt="(.*?)" /></a>|is',$xx, $matches, PREG_SET_ORDER);

where $xx is the entire webpage content as a string, to find all occurrences of matches.

This sets $matches to a two dimensional array which I can then loop through with a for statement based on the length of $matches and use for example ..

$matches[$i][1] which is would be the first (.*?)

$matches[$i][2] which is would be the second (.*?)

and so on....

My question is how can this be replicated in java? I've been reading tutorials and blogs on java regex and have been using Pattern and Matcher but can't seem to figure it out. Also, matcher never finds anything. so my while(matcher.find()) have been futile and usually throws an error saying no matches have been found yet

This is my java code for the pattern to be matched is ...

String pattern = new String(
    "<a href=\"http://www.example.com/photoid/(w+)\"><img src=\"(w+)\" alt=\"(w+)\" /></a>");

I've also tried ..

String pattern = new String(
    "<a href=\"http://www.example.com/photoid/(.*?)\"><img src=\"(.*?)\" alt=\"(.*?)\" /></a>");

and 

String pattern = new String(
    "<a href=\"http://www.example.com/photoid/(\\w+)\"><img src=\"(\\w+)\" alt=\"(\\w+)\" /></a>");

no matches are ever found.

Upvotes: 0

Views: 128

Answers (2)

SamYonnou
SamYonnou

Reputation: 2068

The regex you posted worked for me so perhaps your fault is in how you use it :

String test = "<html>\n<a href=\"http://www.mysite.com/photoid/potato.html\"><img src=\"quack-quack\" alt=\"hi\" /></a>\n</html>";
// This is exactly the pattern code you posted :
String pattern = new String(
    "<a href=\"http://www.mysite.com/photoid/(.*?)\"><img src=\"(.*?)\" alt=\"(.*?)\" /></a>");

Pattern p = Pattern.compile(pattern);
Matcher m = p.matcher(test);
m.find(); // returns true

See Java Tutorial on how this should be used.

Upvotes: 1

user557597
user557597

Reputation:

Not an expert on Java, but shouldn't the strings escape double quotes and escapes?

 "<a href=\"http://www.mysite.com/photoid/(.*?)\"><img src=\"(.*?)\" alt=\"(.*?)\" /></a>"
 or
 "<a\\ href=\"http://www.mysite.com/photoid/(.*?)\"><img\\ src=\"(.*?)\"\\ alt=\"(.*?)\"\\ /></a>"

Upvotes: 1

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