echoxul.util.bean
Class ExpressionParser

java.lang.Object
  echoxul.util.bean.ExpressionParser

public class ExpressionParser

extends java.lang.Object

The ExpressionParser class is responsible for parsing simple expressions into an Object value suitable for assignment. The expression syntax is quite simple and is constituted by the following types:

• String: Represented by text within double quotes
• Integer: Represented by a sequence of digits
• Boolean: Represented by the word "true" or "false"
• Object: Represented by a word followed by open parenthesis, a comma delimitted parameter list and a closing parenthesis.
• Object Field: Represented by a word followed by a dot and the field name

Examples:

• String: "This is a string"
• Integer: 1234
• Boolean: true
• Object: color(1, 2, 3)
• Object: color(12345)
• Object Field: color.RED

This class also has support for reading an entire set of properties in standard java properties file format.

Author:

Terry Laurenzo

Constructor Summary

ExpressionParser()

Method Summary

java.lang.Object	parseExpression(java.lang.String expr) Parse an expression into a value.
java.util.Map	parseProperties(java.io.Reader in) Parse from a Reader that represents a properties file.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExpressionParser

public ExpressionParser()

Method Detail

parseProperties

public java.util.Map parseProperties(java.io.Reader in)
                              throws java.lang.IllegalArgumentException,
                                     java.io.IOException

Parse from a Reader that represents a properties file. This will return a Map of all associations in the file. The syntax is identical to standard java property files

Throws:

java.lang.IllegalArgumentException

java.io.IOException

parseExpression

public java.lang.Object parseExpression(java.lang.String expr)
                                 throws java.lang.IllegalArgumentException

Parse an expression into a value. Throw an IllegalArgumentException on syntax error.

Throws:

java.lang.IllegalArgumentException