Matcher for regular expression not detecting correct

Issue

I have set up the following patterns:

Pattern regExAllPattern = Pattern.compile("/customers");
Pattern regExIdPattern = Pattern.compile("/customers/([0-9A-Za-z]{32})");           
Pattern regExCategoryPattern = Pattern.compile("/customers/category/([0-9A-Za-z]+)");

Here I collect the incoming path:

String pathInfo = req.getPathInfo();

Which I try to match with the resular expressions

Matcher matchRecord = regExIdPattern.matcher(pathInfo); Matcher matchCollection = regExAllPattern.matcher(pathInfo);
Matcher matchCollectionCategory = regExCategoryPattern.matcher(pathInfo);

Then I act upon the matchers above:

if (matchRecord.find()) {
    System.out.println("FIND CUSTOMER RECORD");
    System.out.println("====================");
    //do something
    
} else if (matchCollection.find()) {
    System.out.println("FIND ALL CUSTOMERS");
    System.out.println("====================");
    //do domething
    
} else if (matchCollectionCategory.find()) {
    String category = matchCollectionCategory.group(1); // .group(1);
    System.out.println("FIND CUSTOMERS BY CATEGORY: " + category);
    System.out.println("====================");
    //do something
    
} else {
    System.out.println("can not find match");
}

Now when I open an URL view to find customers by category the pathinfo is as followed:

HTTP JVM: PATHINFO received = /xsp/customers/category/edd

However matchCollection.find() returns true so I get as output:

HTTP JVM: FIND ALL CUSTOMERS

What am I doing wrong here? What must I do to make sure that matchCollection.find() returns false for incoming path /xsp/customers/category/edd ?

Solution

Because it matches. The string /customers is found in the url.

You can build a more complex regex, or the easy way is starting the if sequences by the most explicit first ending with the shortest pattern:

if (matchCollectionCategory.find()) {
    String category = matchCollectionCategory.group(1); // .group(1);
    System.out.println("FIND CUSTOMERS BY CATEGORY: " + category);
    System.out.println("====================");
    //do something

} else if (matchRecord.find()) {
    System.out.println("FIND CUSTOMER RECORD");
    System.out.println("====================");
    //do something
    
} else if (matchCollection.find()) {
    System.out.println("FIND ALL CUSTOMERS");
    System.out.println("====================");
    //do domething
        
} else {
    System.out.println("can not find match");
}

There are two (among many others of course) special chars:

• ^ means start of the sequence
• $ means end of sequence

So, if you want a String to match exactly /customers and nothing else, you would use ^/customers$. That pattern will not match against whatever/customers/whatever. But without those, the matcher will try to find the sequence in whatever part of the String. Please refer to java Pattern class for more info about pattern matching; you can find there all the available options.

Answered By - gmanjon