How to find string pattern in a string expression Java?

Question

I have a string expressions like this:

(code   name   credits) or ((code   name   credits) and (code   name   credits))

I want to recognize all (code name credits) combinations in the string, and replace them with a value.

Code is a combination of letters and numbers.

Name is a combination of words, separated by a single space, words can have both letters and numbers.

Credit is a number.

Each component is separated by a tab .

An actual example of (code name credits) combination is the following:

IABIG-02    Computer Graphics    5

This is not related to the question, but this is what I want to achieve:

Input :

(IABIG-02    Computer Graphics    5) or ((AIBJH88    Computer Vision    5) and (AIKKH10    Computer Architecture    5))

Output :

T or (F and T) 

Answer 1

Here is a potential way to do it, I could not find any clean way to implement it:

String value = "(IABIG-02\tComputer Graphics\t5) or ((AIBJH88\tComputer Vision\t5) and (AIKKH10\tComputer Architecture\t5))";
Pattern pattern = Pattern.compile("\\((\\w|-)+\\t\\w+( \\w+)*\\t\\d\\)");
Matcher matcher = pattern.matcher(value);
StringBuilder builder = new StringBuilder(value.length());
Map<String, Character> replacements = new HashMap<>();
char c = 'A';
int index = 0;
while (matcher.find(index)) {
    builder.append(value, index, matcher.start());
    String found = matcher.group();
    Character replacement = replacements.get(found);
    if (replacement == null) {
        replacement = c++;
        replacements.put(found, replacement);
    }
    builder.append(replacement);
    index = matcher.end();
}
if (index < value.length()) {
    builder.append(value, index, value.length());
}

System.out.println(builder);

Output:

A or (B and C)

It replaces all patterns found with a replacement character starting from A . I use a Map in order to be able to reuse the character previously given to the same exact pattern.