com.nway.spring.jdbc.bean.BeanHandler.java Source code

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Here is the source code for com.nway.spring.jdbc.bean.BeanHandler.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.nway.spring.jdbc.bean;

import java.sql.ResultSet;
import java.sql.SQLException;

import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.ResultSetExtractor;

import com.nway.spring.classwork.DynamicObjectException;

/**
 * <code>ResultSetHandler</code> implementation that converts the first <code>ResultSet</code> row
 * into a JavaBean. This class is thread safe.
 *
 * @param <T> the target bean type
 * @see org.apache.commons.dbutils2.ResultSetHandler
 */
public class BeanHandler<T> implements ResultSetExtractor<T> {

    /**
     * The Class of beans produced by this handler.
     */
    private final Class<T> type;

    private String cacheKey;

    private final BeanProcessor beanProcessor = BeanProcessorFactory.getBeanProcessor();

    public BeanHandler(Class<T> type, String cacheKey) {

        this.type = type;
        this.cacheKey = cacheKey;
    }

    /**
     * Convert the first row of the <code>ResultSet</code> into a bean with the <code>Class</code>
     * given in the constructor.
     *
     * @param rs <code>ResultSet</code> to process.
     * @return An initialized JavaBean or <code>null</code> if there were no rows in the
     * <code>ResultSet</code>.
     *
     * @throws SQLException if a database access error occurs
     * @see org.apache.commons.dbutils2.ResultSetHandler#handle(java.sql.ResultSet)
     */
    @Override
    public T extractData(ResultSet rs) throws DataAccessException {

        try {
            return rs.next() ? beanProcessor.toBean(rs, type, cacheKey) : null;
        } catch (SQLException e) {
            throw new DynamicObjectException(" [ " + this.type + " ]", e);
        }
    }

}