com.sharksharding.sql.SQLTemplate.java Source code

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Here is the source code for com.sharksharding.sql.SQLTemplate.java

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/*
 * Copyright 2015-2101 gaoxianglong
 *
 * 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.sharksharding.sql;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.sharksharding.exception.XmlResolveException;

/**
 * ?sql?
 * 
 * @author gaoxianglong
 * 
 * @version 1.4.1
 */
public class SQLTemplate {
    private String path;
    private Map<String, String> sqlMap;
    private final String xpathExpression = "//sql";
    private final String name = "name";
    private Logger logger = LoggerFactory.getLogger(SQLTemplate.class);

    private SQLTemplate(String path) {
        this.path = path;
        sqlMap = new ConcurrentHashMap<String, String>();
        load();
    }

    /**
     * ?sql.xml?
     * 
     * @author gaoxianglong
     * 
     * @exception FileNotFoundException
     * 
     * @exception IOException
     * 
     * @return void
     */
    private void load() {
        if (null != path) {
            InputStream in = null;
            try {
                /* ??classpathsql?? */
                if (path.indexOf("classpath:") != -1) {
                    /* classpath?sql? */
                    in = this.getClass().getResourceAsStream("/" + path.split("classpath:")[1]);
                }
                if (null == in) {
                    /* ?sql? */
                    in = new FileInputStream(path);
                    resolveXml(in);
                } else {
                    resolveXml(in);
                }
                logger.info("load sql file success");
            } catch (FileNotFoundException e) {
                throw new com.sharksharding.exception.FileNotFoundException(e.toString());
            } finally {
                if (null != in) {
                    try {
                        in.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    }

    /**
     * dom4j?xml
     * 
     * @author gaoxianglong
     * 
     * @param in
     *            ?
     * 
     * @exception XmlResolveException
     * 
     * @return void
     */
    @SuppressWarnings("unchecked")
    private void resolveXml(InputStream in) {
        if (null == in)
            return;
        Document document = null;
        SAXReader saxReader = new SAXReader();
        try {
            document = saxReader.read(in);
        } catch (DocumentException e) {
            throw new XmlResolveException("xml resolve fail");
        }
        Element root = document.getRootElement();
        List<Element> elements = root.selectNodes(xpathExpression);
        if (!elements.isEmpty()) {
            for (Element element : elements) {
                final String sql = element.attribute(name).getValue();
                sqlMap.put(sql, element.getText());
            }
        } else {
            throw new XmlResolveException("element <sql/> not found");
        }
    }

    /**
     * ?????sql?
     * 
     * @author gaoxianglong
     * 
     * @param key
     *            sql??
     * 
     * @param params
     *            ??
     * 
     * @return String sql?
     */
    public String getSql(String key, Map<String, ?> params) {
        final String sql = RenderSQLTemplate.render(sqlMap.get(key), params);
        /* ?SQL?WHERE????? */
        return SQLIsWhereColumn.isColumn(sql) ? sql : null;
    }
}