tpitner / microval

Ultra lightweight Java/Android validation framework

microval

Ultra lightweight Java/Android validation framework

Description

• Library for conversion and validation
• Extremely simple & easy to use
• Strongly typed: boolean, int, double, String, regex validated String, Path supported
• Allows provision of default values when input is missing (null) or invalid
• Allows to specify min...max ranges for numeric types (int, double)
• Allows to specify minimal and maximal length of String
• Offers detailed diagnostics, distinguishes between missing on invalid inputs
• Is fully thread-safe

Usage

• Create Patterns (either BooleanPattern, IntPattern, DoublePattern, StringPattern, RegexPattern, PathPattern) using constructors with Pattern name and description which is used to indicate errors in missing or invalid.
• Modify them by adding default values -- ifMissing(valueIfMissing), ifInvalid(valueIfInvalid).
• Overloaded methods may set also error messages -- ifMissing(valueIfMissing, ifMissingMessage), ifInvalid(valueIfInvalid, ifInvalidMessage).
• You may use patterns to match String inputs, i.e. convert and validate them to resulting typed values.
• The match returns Result which can be queried, e.g.
• isValid() true iff the match(input) matched,
• The value converted and validated: eg. in case of IntPattern int getInt() returns the integer read from input String,
• Feedback: getMessage() returns error message in case the input was missing or not valid.
• Validation is thread-safe (ie. one can validate against the same Pattern in multiple threads concurrently).

Example

Arrays.asList(
      new BooleanPattern("myBool", "myBool parameter")
        .ifMissing(true, "You could provide boolean"),

      new IntPattern("myInt", "myInt parameter")
        .range(-10, 1000)
        .ifMissing(0, "You could provide int")
        .ifInvalid(-1, "You should provide int but provided something else"),

      new DoublePattern("myDouble", "myDouble parameter")
        .range(-123.4, 123.4)
        .ifMissing(0.0, "You could provide double")
        .ifInvalid(-1.0, "You should provide provide double but..."),

      new StringPattern("myString", "myString parameter")
        .length(1, 10).ifMissing("none").ifInvalid("invalid"),
        
      new RegexPattern("myRegex", "myRegex parameter")
        .pattern("\\d*").ifMissing("none").ifInvalid("invalid"),
        
      new PathPattern("myPath", "myPath parameter")
        .ifMissing(Path.of("nonepath"))
        .ifInvalid(Path.of("invalidpath"))
).forEach(v -> {
  Result result = v.match("x100");
  System.out.println(result.isValid() + " " + v);
});