IBatisSqlActionShardingRule.java

/**
 * Copyright 1999-2011 Alibaba Group
 *
 * 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.alibaba.cobar.client.router.rules.ibatis;

import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.Validate;
import org.mvel2.MVEL;
import org.mvel2.integration.VariableResolverFactory;
import org.mvel2.integration.impl.MapVariableResolverFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alibaba.cobar.client.router.support.IBatisRoutingFact;

public class IBatisSqlActionShardingRule extends AbstractIBatisOrientedRule {

    private transient final Logger logger = LoggerFactory
                                                  .getLogger(IBatisSqlActionShardingRule.class);

    public IBatisSqlActionShardingRule(String pattern, String action, String attributePattern) {
        super(pattern, action, attributePattern);
    }

    public boolean isDefinedAt(IBatisRoutingFact routingFact) {
        Validate.notNull(routingFact);
        boolean matches = StringUtils.equals(getTypePattern(), routingFact.getAction());
        if (matches) {
            try {
                Map<String, Object> vrs = new HashMap<String, Object>();
                vrs.putAll(getFunctionMap());
                vrs.put("$ROOT", routingFact.getArgument()); // add top object reference for expression
                VariableResolverFactory vrfactory = new MapVariableResolverFactory(vrs);
                if (MVEL.evalToBoolean(getAttributePattern(), routingFact.getArgument(), vrfactory)) {
                    return true;
                }
            } catch (Throwable t) {
                logger
                        .info(
                                "failed to evaluate attribute expression:'{}' with context object:'{}'\n{}",
                                new Object[] { getAttributePattern(), routingFact.getArgument(), t });
            }
        }

        return false;
    }

    @Override
    public String toString() {
        return "IBatisSqlActionShardingRule [getAttributePattern()=" + getAttributePattern()
                + ", getAction()=" + getAction() + ", getTypePattern()=" + getTypePattern() + "]";
    }

}