Class PredicateParser


  • public class PredicateParser
    extends java.lang.Object
    Parser that can build a predicate from a string representation. The underlying syntax is quite simple, and example is shown below:

    path["/MyPath"] or (method[value="POST"] and not headersPresent[value={Content-Type, "Content-Encoding"}, ignoreTrailer=true]

    The following boolean operators are built in, listed in order or precedence: - not - and - or

    They work pretty much as you would expect them to. All other tokens are taken to be predicate names. If the predicate does not require any parameters then the brackets can be omitted, otherwise they are mandatory.

    If a predicate is only being passed a single parameter then the parameter name can be omitted. Strings can be enclosed in optional double or single quotations marks, and quotation marks can be escaped using \".

    Array types are represented via a comma separated list of values enclosed in curly braces.

    TODO: should we use antlr (or whatever) here? I don't really want an extra dependency just for this...

    Author:
    Stuart Douglas
    • Constructor Summary

      Constructors 
      Constructor Description
      PredicateParser()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static Predicate parse​(java.lang.String string, java.lang.ClassLoader classLoader)  
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • PredicateParser

        public PredicateParser()
    • Method Detail

      • parse

        public static final Predicate parse​(java.lang.String string,
                                            java.lang.ClassLoader classLoader)