package org.codehaus.plexus.interpolation;

/*
 * Copyright 2001-2008 Codehaus Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

Signals an unrecoverable error in the process of interpolating a string, such as the detection of an expression cycle. Errors resolving individual values from expressions, such as those that happen when an object wrapped in an ObjectBasedValueSource doesn't have the property represented by a particular expression part, should NOT result in InterpolationExceptions being thrown. Instead, they should be reported in the feedback from the ValueSource, which is propagated out through Interpolator.getFeedback(). /**
 * Signals an unrecoverable error in the process of interpolating a string, such
 * as the detection of an expression cycle. Errors resolving individual values
 * from expressions, such as those that happen when an object wrapped in an
 * {@link ObjectBasedValueSource} doesn't have the property represented by a
 * particular expression part, should <b>NOT</b> result in InterpolationExceptions
 * being thrown. Instead, they should be reported in the feedback from the {@link ValueSource},
 * which is propagated out through {@link Interpolator#getFeedback()}.
 * 
 */
public class InterpolationException
    extends Exception
{

    private static final long serialVersionUID = 1L;
    
    private final String expression;

    
Params:
message – The general description of the problem
expression – The expression that triggered the problem
cause – The wrapped exception/**
     * @param message The general description of the problem
     * @param expression The expression that triggered the problem
     * @param cause The wrapped exception
     */
    public InterpolationException( String message,
                                      String expression,
                                      Throwable cause )
    {
        super( buildMessage( message, expression ), cause );
        this.expression = expression;
    }

    
Params:
message – The general description of the problem
expression – The expression that triggered the problem/**
     * @param message The general description of the problem
     * @param expression The expression that triggered the problem
     */
    public InterpolationException( String message, String expression )
    {
        super( buildMessage( message, expression ) );
        this.expression = expression;
    }

    private static String buildMessage( String message,
                                        String expression )
    {
        return "Resolving expression: '" + expression + "': " + message;
    }

    
Returns:
The expression that triggered this exception./**
     * @return The expression that triggered this exception.
     */
    public String getExpression()
    {
        return expression;
    }

}