/*
* Copyright 2002-2016 the original author or authors.
*
* 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.
*/
package org.springframework.expression.spel.ast;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import org.springframework.expression.EvaluationException;
import org.springframework.expression.spel.ExpressionState;
import org.springframework.expression.spel.SpelEvaluationException;
import org.springframework.expression.spel.SpelMessage;
import org.springframework.expression.spel.support.BooleanTypedValue;
/**
* Implements the matches operator. Matches takes two operands:
* The first is a String and the second is a Java regex.
* It will return {@code true} when {@link #getValue} is called
* if the first operand matches the regex.
*
* @author Andy Clement
* @author Juergen Hoeller
* @since 3.0
*/
public class OperatorMatches extends Operator {
private final ConcurrentMap<String, Pattern> patternCache = new ConcurrentHashMap<>();
public OperatorMatches(int pos, SpelNodeImpl... operands) {
super("matches", pos, operands);
}
/**
* Check the first operand matches the regex specified as the second operand.
* @param state the expression state
* @return {@code true} if the first operand matches the regex specified as the
* second operand, otherwise {@code false}
* @throws EvaluationException if there is a problem evaluating the expression
* (e.g. the regex is invalid)
*/
@Override
public BooleanTypedValue getValueInternal(ExpressionState state) throws EvaluationException {
SpelNodeImpl leftOp = getLeftOperand();
SpelNodeImpl rightOp = getRightOperand();
Object left = leftOp.getValue(state, String.class);
Object right = getRightOperand().getValueInternal(state).getValue();
if (!(left instanceof String)) {
throw new SpelEvaluationException(leftOp.getStartPosition(),
SpelMessage.INVALID_FIRST_OPERAND_FOR_MATCHES_OPERATOR, left);
}
if (!(right instanceof String)) {
throw new SpelEvaluationException(rightOp.getStartPosition(),
SpelMessage.INVALID_SECOND_OPERAND_FOR_MATCHES_OPERATOR, right);
}
try {
String leftString = (String) left;
String rightString = (String) right;
Pattern pattern = this.patternCache.get(rightString);
if (pattern == null) {
pattern = Pattern.compile(rightString);
this.patternCache.putIfAbsent(rightString, pattern);
}
Matcher matcher = pattern.matcher(leftString);
return BooleanTypedValue.forValue(matcher.matches());
}
catch (PatternSyntaxException ex) {
throw new SpelEvaluationException(rightOp.getStartPosition(), ex, SpelMessage.INVALID_PATTERN, right);
}
}
}