pageiteratorjdbctemp.java

来自「一个非常好的FRAMWRK!是一个外国组织做的!不!」· Java 代码 · 共 154 行

/*
 * Copyright 2003-2005 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.jdon.model.query;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import javax.sql.DataSource;

import org.apache.log4j.Logger;

import com.jdon.controller.model.PageIterator;
import com.jdon.util.DbUtil;

/**
 * Batch query JDBC Template
 * 
 * this class can be directly by application system.
 * 
 * @author <a href="mailto:[e-mail]">banq </a>
 *  
 */
public  class PageIteratorJDBCTemp implements PageIteratorJDBC {
    private final static Logger logger = Logger.getLogger(PageIteratorJDBCTemp.class);

    private DataSource dataSource;
    private JdbcUtil jdbcUtil;

    public PageIteratorJDBCTemp(DataSource dataSource) {
        this.dataSource = dataSource;
        this.jdbcUtil = new JdbcUtil();
    }

    /*
     * (non-Javadoc)
     * 
     * @see com.jdon.model.query.PageIteratorJDBC#fetchDataAllCount(java.lang.Object,
     *      java.lang.String)
     */
    public int fetchDataAllCount(Collection queryParams, String sqlquery)
            throws Exception {
        logger.debug("--> enter fetchDataAllCount ");
        Connection c = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        int ret = 0;
        try {
            c = dataSource.getConnection();
            ps = c.prepareStatement(sqlquery,
                    ResultSet.TYPE_SCROLL_INSENSITIVE,
                    ResultSet.CONCUR_READ_ONLY);

            jdbcUtil.setQueryParams(queryParams, ps);

            rs = ps.executeQuery();
            if (rs.first()) {
                ret = rs.getInt(1);
            }
        } catch (SQLException se) {
            throw new Exception("SQLException: " + se.getMessage());
        } catch (Exception ex) {
            logger.error(ex);
            throw new Exception(ex);                        
        } finally {
            if (rs != null)
                rs.close();
            if (ps != null)
                ps.close();
            if (c != null)
                c.close();
        }
        logger.debug("--> fetchDataAllCount is" + ret);
        return ret;
    }

    /*
     * (non-Javadoc)
     * 
     * @see com.jdon.model.query.PageIteratorJDBC#fetchDatas(java.util.Collection,
     *      java.lang.String, int, int)
     */
    public PageIterator fetchDatas(Collection queryParams, String sqlquery,
            int start, int count) throws Exception {
        logger.debug("--> fetchDatas from start=" + start + " size=" + count);
        Connection c = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        PageIterator pageIterator = null;
        boolean hasNext = false;
        if (count > 200)
            count = 200;
        try {
            c = dataSource.getConnection();

            DbUtil.testConnection(c);
            ps = c.prepareStatement(sqlquery,
                    ResultSet.TYPE_SCROLL_INSENSITIVE,
                    ResultSet.CONCUR_READ_ONLY);

            jdbcUtil.setQueryParams(queryParams, ps);

            rs = ps.executeQuery();
            if (DbUtil.supportsFetchSize)
                rs.setFetchSize(count);
            if (start >= 0 && rs.absolute(start + 1)) {
                List items = new ArrayList(count);
                do {
                    Object result = rs.getObject(1);
                    items.add(result);
                } while ((hasNext = rs.next()) && (--count > 0));
                Object[] itemsA = items.toArray();
                pageIterator = new PageIterator(itemsA, start, hasNext);
            } else
                pageIterator = new PageIterator(PageIterator.EMPTY, start,
                        hasNext);
            logger.debug("--> get PageIterator succefully ..");
        } catch (SQLException se) {
            logger.error(se);
            throw new Exception("SQLException: " + se.getMessage());
        } catch (Exception ex) {
            logger.error(ex);
            throw new Exception(ex);            
        } finally {
            if (rs != null)
                rs.close();
            if (ps != null)
                ps.close();
            if (c != null)
                c.close();
        }
        return pageIterator;
    }


}