Package com.lonniepryor.blues.util

Common utility classes used throughout the Blues Framework.

See:
Description

Interface Summary

Expression.Builder

Strategy interface used to construct in-memory representations of an expression.

Class Summary

BeanHelper	Helper class that introspects and provides access to information about a JavaBean.
Characters	Specification interface for identifying Characters.
Constructors	Specification interface for identifying Constructors.
EnumerationChain	Simple implementation of the Composite pattern for java.util.Enumeration.
Expression	Helper class for parsing logical expressions and combining them using the AND, OR, and NOT operations.
Fields	Specification interface for identifying Fields.
Methods	Specification interface for identifying Methods.
Parameters	Specification interface for identifying ordered sequences of Types.
Parameters.Builder	Helper class for sequentially constructing the elements of a common TokenizedStrings specification.
Strings	Specification interface for identifying Strings or parts of Strings.
Strings.Builder	Helper class for sequentially constructing the elements of a common Strings specification.
Throwables	Specification interface for identifying sets of Types.
TokenizedStrings	Specification interface for identifying Strings or parts of Strings that are delimeted by a paticular character.
TokenizedStrings.Builder	Helper class for sequentially constructing the elements of a common TokenizedStrings specification.
Types	Specification interface for identifying types and classes.

Exception Summary

BluesException	Base exception thrown by the Blues Framework.
ParseException	Exception thrown when a string is unable to be parsed.
ReflectionException	Exception thrown when a reflective invocation fails.

Package com.lonniepryor.blues.util Description

Common utility classes used throughout the Blues Framework.

Overview

This package serves as the functional base to the entire Blues Framework, and maintains no dependancies on any resources besides those available in a basic Java 2 runtime environment. The primary features of this package are the Specification classes, as they can greatly simplify complicated reflection analysis routines.

Specifications

Specifications are objects that encapsulate a single boolean condition and can evaluate that condition for any number of canidate values. For example, a simple Specification for matching upper-case characters might look like:

        class IsUpperCase {
          boolean isSatisfiedby(char canidate) {
            return Character.isUpperCase(canidate);
           }
         }
      

While this class by itself is of little practical value, Specifications may also provide means to form composite Specifications using the logical AND, OR, and NOT operations. Properly applied, the Specification pattern can make testing complicated binary conditions much easier and simpler to understand by encapsulating complex if-else statements in a single object.

Blues provides a set of Specifications targeted at easing the interaction with the Java language reflection API. Using the classes in this package, programmers can easily formulate complex nested conditions to be tested against language primitives like Methods and Fields. The Specifications can also parse a very AspectJ-like pattern syntax into predicates, making defining these conditions outside of source code expressive and succinct.

The following classes in this package implement the Specification pattern:

• Characters
• Strings
• TokenizedStrings
• Types
• Fields
• Parameters
• Throwables
• Constructors
• Methods

Other Utilities

Blues provides various other utilities including a bean introspector, a composite Enumeration class, and a textual predicate expression parser.