/*
* Copyright 2010-2011 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 com.starflow.wf.engine.core.expression;
import java.util.HashMap;
import java.util.Map;
import com.starflow.wf.engine.core.expression.aviator.AbstractAviatorExpressionHandler;
import com.starflow.wf.engine.core.expression.xpath.XPathBuilder;
import com.starflow.wf.engine.model.elements.TransitionElement;
/**
*
* @author libinsong1204@gmail.com
* @version 1.0
*/
public class SimpleExpressionHandler extends AbstractAviatorExpressionHandler {
private static final String XPATH_PREFIX = "xp:";
private static Map<String, String> compTypes = new HashMap<String, String>();
static {
compTypes.put("EQ", "==");
compTypes.put("GT", ">");
compTypes.put("LT", "<");
compTypes.put("GE", ">=");
compTypes.put("LE", "<=");
compTypes.put("NE", "!=");
}
@Override
public String buildExpression(TransitionElement transition, Map<String, Object> conditions) {
String compType = compTypes.get(transition.getCompType());
//xpath表达式解析
String leftValue = transition.getLeftValue();
if(leftValue.startsWith(XPATH_PREFIX)) {
leftValue = parserXPath(leftValue, conditions);
}
String expression = "\"" + leftValue + "\" " + compType + " \"" + transition.getRightValue() +"\"";
return expression;
}
/**
* 解析XPath
*
* @param value xp:变量:/Users/User/name
* @param map
* @return
*/
private String parserXPath(String value, Map<String, Object> conditions) {
int index = value.indexOf(":", XPATH_PREFIX.length());
String name =value.substring(XPATH_PREFIX.length(), index);
String xml = (String)conditions.get(name);
if(logger.isDebugEnabled()) {
logger.debug("Xpath 路径：{}, xml内容{}", value, xml);
}
XPathBuilder builder = XPathBuilder.xpath(value.substring(index+1));
String result = builder.evaluate(xml);
if(logger.isDebugEnabled()) {
logger.debug("Xpath 解析结果：{}", result.trim());
}
return result.trim();
}
}