Question

I have an encoded string with the syntax

"encodedProp:encodedValue OPERATOR encodedProp1:encodedValue1"

(the OPERATOR might be AND, OR, NOT, and there are N pairs prop:value).

The "encodedProp", "encodedValue", "encodedProp1", "encodedValue1" … are the encoded strings.

I’d like to use a regular expression to replace the ":" by " = ". Also, the part on the left side of ":" should be replaced by "\"" + left_part + "\"", the right part should be replaced by "'" + right_part + "'".

With the above example, the string after replacing should be:

"\"encodedProp\" = 'encodedValue' OPERATOR \"encodedProp1\" = 'encodedValue1'"

What is the expression I have to use to do this?

Answer 1

OK, I’m going out on a limb here because the problem is not well-defined, but let’s give it a try.

String resultString = subjectString.replaceAll(
    "(?x)(       # Match and capture in backreference number 1:\n" +
    " [^\\s:]+   #  one or more characters except spaces or colons\n" +
    ")           # End of capturing group 1\n" +
    ":           # Match a colon\n" +
    "(           # Match and capture in backreference number 2:\n" +
    " [^\\s:]+   #  one or more characters except spaces or colons\n" +
    ")           # End of capturing group 2", 
    "\"$1\" = '$2'");

This completely ignores the OPERATOR part – it simply looks for sequences of characters that include one colon, and wraps them in single/double quotes, replacing the colon along the way.