org.springframework.data.gemfire.examples.CalculateTotalSalesForProduct.java Source code

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Here is the source code for org.springframework.data.gemfire.examples.CalculateTotalSalesForProduct.java

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/*
 * Copyright 2012 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.data.gemfire.examples;

import java.math.BigDecimal;

import javax.annotation.Resource;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.data.gemfire.GemfireTemplate;
import org.springframework.data.gemfire.examples.domain.LineItem;
import org.springframework.data.gemfire.examples.domain.Product;
import org.springframework.data.gemfire.examples.domain.Order;
import org.springframework.stereotype.Component;

import com.gemstone.gemfire.cache.Region;
import com.gemstone.gemfire.cache.execute.FunctionAdapter;
import com.gemstone.gemfire.cache.execute.FunctionContext;
import com.gemstone.gemfire.cache.execute.ResultSender;
import com.gemstone.gemfire.cache.query.SelectResults;

/**
 * A GemFire Function for aggregating and calculating results on the cache server. 
 * 
 * This function computes the total sales for a given product.
 * 
 * @author David Turanski
 *
 */
@SuppressWarnings("serial")
@Component
public class CalculateTotalSalesForProduct extends FunctionAdapter {
    private static Log log = LogFactory.getLog(CalculateTotalSalesForProduct.class);

    @Resource(name = "productTemplate")
    private GemfireTemplate productTemplate;
    @Resource(name = "Order")
    private Region<Long, Order> orderRegion;

    /* (non-Javadoc)
     * @see com.gemstone.gemfire.cache.execute.FunctionAdapter#execute(com.gemstone.gemfire.cache.execute.FunctionContext)
     */
    @Override
    public void execute(FunctionContext functionContext) {
        ResultSender<BigDecimal> resultSender = functionContext.getResultSender();

        String productName = (String) functionContext.getArguments();

        log.debug("searching for product name '" + productName + "'");

        SelectResults<Product> results = productTemplate.query("name = '" + productName + "'");

        if (results.isEmpty()) {
            log.warn("cannot find product '" + productName + "'");
            resultSender.lastResult(new BigDecimal(0.0));
            return;
        }

        Product product = results.asList().get(0);

        long productId = product.getId();

        BigDecimal total = new BigDecimal(0.0);

        for (Order order : orderRegion.values()) {
            for (LineItem lineItem : order.getLineItems()) {
                if (lineItem.getProductId() == productId) {
                    total = total.add(lineItem.getTotal());
                }
            }
        }

        resultSender.lastResult(total.setScale(2, BigDecimal.ROUND_CEILING));
    }

    /* (non-Javadoc)
     * @see com.gemstone.gemfire.cache.execute.FunctionAdapter#getId()
     */
    @Override
    public String getId() {
        return getClass().getSimpleName();
    }
}