如何在Java中查找表达式，求值和替换？

Question

I have the following expressions inside a String (that comes from a text file):

{gender=male#his#her}
{new=true#newer#older}

And I would like to:

1. Find the occurences of that pattern {variable=value#if_true#if_false}
2. Temporarily store those variables in fields such as variableName , variableValue , ifTrue , ifFalse as String s.
3. Evaluate an expression based on variableName and variableValue according to local variables (like String gender = "male" and String new = "true").
4. And finally replace the pattern with ifTrue or ifFalse according to (3).

Should I use String.replaceAll() in some way, or how do I look for this expression and save the strings that are inside? Thanks for your help

UPDATE

It would be something like PHP's preg_match_all .

UPDATE 2

I solved this by using Pattern and Matcher as I post as an answer below.

Answer 1

If the strings always take this format, then string.split('#') is probably the way to go. This will return an array of strings in the '#' separator (eg "{gender=male#his#her}".split('#') = {"{gender=male", "his", "her}"}; use substring to remove the first and last character to get rid of the braces)

Answer 2

After strugling for a while I managed to get this working using Pattern and Matcher as follows:

// \{variable=value#if_true#if_false\}
Pattern pattern = Pattern.compile(Pattern.quote("\\{") + "([\\w\\s]+)=([\\w\\s]+)#([\\w\\s]+)#([\\w\\s]+)" + Pattern.quote("\\}"));
Matcher matcher = pattern.matcher(doc);

// if we'll make multiple replacements we should keep an offset
int offset = 0;

// perform the search
while (matcher.find()) {
    // by default, replacement is the same expression
    String replacement = matcher.group(0);
    String field = matcher.group(1);
    String value = matcher.group(2);
    String ifTrue = matcher.group(3);
    String ifFalse = matcher.group(4);

    // verify if field is gender
    if (field.equalsIgnoreCase("Gender")) {
        replacement = value.equalsIgnoreCase("Female")?ifTrue:ifFalse;
    }

    // replace the string
    doc = doc.substring(0, matcher.start() + offset) + replacement + doc.substring(matcher.end() + offset);

    // adjust the offset
    offset += replacement.length() - matcher.group(0).length();
}