com.revolsys.util

Class JexlUtil

java.lang.Object

com.revolsys.util.JexlUtil

public final class JexlUtil
extends Object

The JexlUtil is a utility class for processing strings that contain patterns from the Jakarta Commons Jexl library.

Author:

Paul Austin

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_EXPRESSION_PATTERN The default expression pattern matching expressions in the form ${el}.

Method Summary

Methods

Modifier and Type	Method and Description
static org.apache.commons.jexl.Expression	createExpression(String expression) Convert expressions into valid JexlExpressions, if the string does not contain any expressions in the form ${el} then null will be returned and the caller can use the raw string.
static org.apache.commons.jexl.Expression	createExpression(String expression, String expressionPattern) Convert expressions into valid JexlExpressions, if the string does not contain any expressions that match the expressionPattern then null will be returned and the caller can use the raw string.
static Object	evaluateExpression(org.apache.commons.jexl.JexlContext context, org.apache.commons.jexl.Expression expression)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_EXPRESSION_PATTERN

public static final String DEFAULT_EXPRESSION_PATTERN

The default expression pattern matching expressions in the form ${el}.

See Also:

Constant Field Values

Method Detail

createExpression

public static org.apache.commons.jexl.Expression createExpression(String expression)
                                                           throws Exception

Convert expressions into valid JexlExpressions, if the string does not contain any expressions in the form ${el} then null will be returned and the caller can use the raw string.

Parameters:

expression - The string containing expressions.

Returns:

The expression object for the string expression.

Throws:

Exception - If there was an error creating the expression.

createExpression

public static org.apache.commons.jexl.Expression createExpression(String expression,
                                                  String expressionPattern)
                                                           throws Exception

Convert expressions into valid JexlExpressions, if the string does not contain any expressions that match the expressionPattern then null will be returned and the caller can use the raw string.

The expressionPattern can be used to define an alternate pattern than the DEFAULT_EXPRESSION_PATTERN that defines expressions in the form ${el}. The pattern is defined as a Java Regular expression. The contents of the expression part of the pattern must be enclosed in () to define the group. The characters outside the first group will be removed from the string and the expression portion will be added to the expression.

Parameters:

expression - The string containing expressions.

expressionPattern - The regular expression pattern used to identify expressions in the string. The first group in the expression will be used as the expression.

Returns:

The expression object for the string expression.

Throws:

Exception - If there was an error creating the expression.

evaluateExpression

public static Object evaluateExpression(org.apache.commons.jexl.JexlContext context,
                        org.apache.commons.jexl.Expression expression)