| /* |
| * $Id$ |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| package org.apache.tiles; |
| |
| import static org.apache.tiles.CompareUtil.*; |
| |
| /** |
| * It is an expression, along with the expression language (e.g. EL, MVEL, OGNL) |
| * it is expressed with. |
| * |
| * @version $Rev$ $Date$ |
| * @since 2.2.0 |
| */ |
| public class Expression { |
| |
| /** |
| * The expression itself. |
| */ |
| private String expression; |
| |
| /** |
| * The language of the expression. |
| */ |
| private String language; |
| |
| /** |
| * Constructor. |
| * |
| * @param expression The expression itself. |
| * @param language The language of the expression. |
| * @since 2.2.0 |
| */ |
| public Expression(String expression, String language) { |
| this.expression = expression; |
| this.language = language; |
| } |
| |
| /** |
| * Constructor, using the default (i.e. <code>null</code>) language. |
| * |
| * @param expression The expression itself. |
| * @since 2.2.0 |
| */ |
| public Expression(String expression) { |
| this(expression, null); |
| } |
| |
| /** |
| * Copy constructor. |
| * |
| * @param toCopy The expression to copy. |
| * @since 2.2.0 |
| */ |
| public Expression(Expression toCopy) { |
| this.expression = toCopy.expression; |
| this.language = toCopy.language; |
| } |
| |
| /** |
| * Creates an Expression object from a string in the form |
| * <code>LANGUAGE:EXPRESSION</code>. |
| * |
| * @param describedExpression The expression in the form |
| * <code>LANGUAGE:EXPRESSION</code>. The LANGUAGE part should be expressed |
| * only with letters and numbers. |
| * @return The created object, or <code>null</code> if the expression is null. |
| * @since 2.2.0 |
| */ |
| public static Expression createExpressionFromDescribedExpression(String describedExpression) { |
| if (describedExpression != null) { |
| String language = null; |
| String expression = describedExpression; |
| if (describedExpression.matches("[a-zA-Z0-9]+:.+")) { |
| language = describedExpression.substring(0, describedExpression.indexOf(':')); |
| expression = describedExpression.substring(describedExpression.indexOf(':') + 1); |
| } |
| return new Expression(expression, language); |
| } |
| |
| return null; |
| } |
| |
| /** |
| * Creates an Expression object from the expression and its language. |
| * |
| * @param expression The expression itself. |
| * @param language The language of the expression. |
| * @return The created object, or <code>null</code> if the expression is null. |
| * @since 2.2.0 |
| */ |
| public static Expression createExpression(String expression, String language) { |
| if (expression != null) { |
| return new Expression(expression, language); |
| } |
| |
| return null; |
| } |
| |
| /** |
| * Returns the expression string. |
| * |
| * @return The expression itself. |
| * @since 2.2.0 |
| */ |
| public String getExpression() { |
| return expression; |
| } |
| |
| /** |
| * Returns the language in which the expression is expressed. |
| * |
| * @return The expression language. |
| * @since 2.2.0 |
| */ |
| public String getLanguage() { |
| return language; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean equals(Object obj) { |
| Expression exp = (Expression) obj; |
| return nullSafeEquals(expression, exp.expression) |
| && nullSafeEquals(language, exp.language); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public int hashCode() { |
| return nullSafeHashCode(expression) + nullSafeHashCode(language); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public String toString() { |
| return (language == null ? "DEFAULT" : language) + ":" + expression; |
| } |
| } |