com.springdeveloper.data.jdbc.batch.JdbcTasklet.java Source code

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Here is the source code for com.springdeveloper.data.jdbc.batch.JdbcTasklet.java

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/*
 * Copyright 2006-2014 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.springdeveloper.data.jdbc.batch;

import java.util.List;
import java.util.Map;

import javax.sql.DataSource;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.batch.core.ExitStatus;
import org.springframework.batch.core.StepContribution;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.scope.context.ChunkContext;
import org.springframework.batch.core.step.tasklet.Tasklet;
import org.springframework.batch.repeat.RepeatStatus;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.jdbc.core.namedparam.BeanPropertySqlParameterSource;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.util.Assert;

/**
 * @author Dave Syer,
 * @author Christian Tzolov
 * @author Thomas Risberg
 * 
 */
public class JdbcTasklet implements Tasklet, InitializingBean {

    private static final Log logger = LogFactory.getLog(JdbcTasklet.class);

    private NamedParameterJdbcTemplate jdbcTemplate;

    private String sql;

    /**
     * An SQL query to execute in the tasklet. The query can be a select,
     * update, delete or insert, and it can contain embedded query parameters
     * using a {@link BeanPropertySqlParameterSource} whose root context is the
     * step context. So for example
     * 
     * <pre>
     * DELETE from LEAD_INPUTS where ID=:jobParameters[idToDelete]
     * </pre>
     * 
     * Note that the syntax for the named parameters is different from and not
     * as flexible as Spring EL. So it might be better anyway if possible to
     * use late binding to push step context properties into the query, e.g.
     * this will work in a bean definition which is step scoped:
     * 
     * <pre>
     * &lt;bean id="tasklet" class="org...JdbcTasklet" scope="step"&gt;
     *   &lt;property name="sql"&gt;
     *     &lt;value&gt;
     * DELETE from LEAD_INPUTS where ID=#{jobParameters['i.to.delete']?:-1}
     *     &lt;/value&gt;
     *   &lt;/property&gt;
     * &lt;/bean&gt;
     * </pre>
     * 
     * @see BeanPropertySqlParameterSource
     * 
     * @param sql the sql to set
     */
    public void setSql(String sql) {
        this.sql = sql;
    }

    /**
     * @param dataSource the dataSource to set
     */
    public void setDataSource(DataSource dataSource) {
        this.jdbcTemplate = new NamedParameterJdbcTemplate(dataSource);
    }

    public void afterPropertiesSet() throws Exception {
        Assert.state(jdbcTemplate != null, "A DataSource must be provided");
        Assert.state(sql != null, "A SQL query must be provided");
    }

    /**
     * Execute the {@link #setSql(String) SQL query} provided. If the query
     * starts with "select" (case insensitive) the result is a list of maps,
     * which is logged and added to the step execution exit status. Otherwise
     * the query is executed and the result is an indication, also in the exit
     * status, of the number of rows updated.
     */
    public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {

        StepExecution stepExecution = chunkContext.getStepContext().getStepExecution();
        ExitStatus exitStatus = stepExecution.getExitStatus();

        if (sql.trim().toUpperCase().startsWith("SELECT")) {
            logger.debug("Executing: " + sql);
            List<Map<String, Object>> result = jdbcTemplate.queryForList(sql,
                    new BeanPropertySqlParameterSource(chunkContext.getStepContext()));
            String msg = "Result: " + result;
            logger.debug(msg);
            stepExecution.setExitStatus(exitStatus.addExitDescription(msg));
        } else {
            logger.debug("Updating : " + sql);
            int updated = jdbcTemplate.update(sql,
                    new BeanPropertySqlParameterSource(chunkContext.getStepContext()));
            String msg = "Updated: " + updated + " rows";
            logger.debug(msg);
            stepExecution.setExitStatus(exitStatus.addExitDescription(msg));
        }
        return RepeatStatus.FINISHED;

    }

}