cn.edu.ahpu.common.dao.key.impl.DefaultUniqueTableApp.java Source code

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/*
 * 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 cn.edu.ahpu.common.dao.key.impl;

import javax.sql.DataSource;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.util.Assert;

import cn.edu.ahpu.common.dao.key.CacheValue;
import cn.edu.ahpu.common.dao.key.UniqueException;
import cn.edu.ahpu.common.dao.key.UniqueTableApp;

/**
 * 
 * @author libinsong1204@gmail.com
 * @version 1.0
 */
public class DefaultUniqueTableApp implements UniqueTableApp {
    private static final Logger logger = LoggerFactory.getLogger(DefaultUniqueTableApp.class);
    protected String selectSQL = null;
    protected String updateSQL = null;
    protected String insertSQL = null;

    private final int initCode = 0;

    protected JdbcTemplate jdbcTemplate = null;

    public DefaultUniqueTableApp(DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);

        this.selectSQL = "SELECT code FROM TPC_PRIMARYKEY WHERE name = ? FOR UPDATE";
        this.updateSQL = "UPDATE TPC_PRIMARYKEY SET code = code + ? WHERE name = ? ";
        this.insertSQL = "INSERT INTO TPC_PRIMARYKEY (code, name) VALUES (?, ?)";
    }

    public CacheValue getCacheValue(int cacheNum, String name) {
        Assert.isTrue(TransactionSynchronizationManager.isSynchronizationActive(), "Transaction must be running");

        CacheValue cache = null;
        try {
            cache = getCurrCode(name);

            if (cache == null) {
                insert(name);
                cache = getCurrCode(name);
            }

            update(cacheNum, name);
            cache.setMaxVal(cache.getMinVal() + cacheNum);
        } catch (Exception e) {
            logger.error("?", e);
        }
        return cache;
    }

    private CacheValue getCurrCode(String name) {
        CacheValue value = null;
        try {
            Long code = jdbcTemplate.queryForLong(this.selectSQL, new Object[] { name });
            value = new CacheValue();
            value.setMinVal(code + 1);
        } catch (EmptyResultDataAccessException e) {
            logger.debug(name + " ");
        } catch (Exception e) {
            throw new UniqueException(name + " ?");
        }
        return value;
    }

    private void insert(String name) {
        jdbcTemplate.update(this.insertSQL, new Object[] { initCode, name });
    }

    private void update(int cacheNum, String name) {
        jdbcTemplate.update(this.updateSQL, new Object[] { cacheNum, name });
    }

    /**
     * @param selectSQL the selectSQL to set
     */
    public void setSelectSQL(String selectSQL) {
        this.selectSQL = selectSQL;
    }

    /**
     * @param updateSQL the updateSQL to set
     */
    public void setUpdateSQL(String updateSQL) {
        this.updateSQL = updateSQL;
    }

    /**
     * @param insertSQL the insertSQL to set
     */
    public void setInsertSQL(String insertSQL) {
        this.insertSQL = insertSQL;
    }

    /**
     * @param jdbcTemplate the simpleJdbcTemplate to set
     */
    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

}