net.paoding.rose.jade.rowmapper.DefaultRowMapperFactory.java Source code

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Here is the source code for net.paoding.rose.jade.rowmapper.DefaultRowMapperFactory.java

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/*
 * Copyright 2009-2010 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 i 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 net.paoding.rose.jade.rowmapper;

import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import net.paoding.rose.jade.annotation.RowHandler;
import net.paoding.rose.jade.statement.StatementMetaData;

import org.apache.commons.lang.ClassUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanInstantiationException;
import org.springframework.jdbc.core.ColumnMapRowMapper;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.SingleColumnRowMapper;

/**
 * ?DAO
 * <p>
 * <ul>
 * <li>int?longprimitive??1</li>
 * <li>Integer?Long??01</li>
 * <li>String?BigDecimal?01</li>
 * <li>java.util.Date???01</li>
 * <li>byte[]????byte[](blob)</li>
 * <li>Blob?Clob?01</li>
 * <li><code>(int[]?String[])?</li>
 * <li>(User[])</li>
 * <li>?(List&lt;Integer&gt;?Set&lt;String&gt): ?</li>
 * <li>?(List&lt;User&gt;?Set&lt;User&gt): ?</li>
 * <li>(Map&lt;String, Date&gt): 2</li>
 * <li>(Map&lt;String, User&gt): </li>
 * <li>(Map&lt;String, String[]&gt): </li>
 * <ul>
 * 
 * @author  [qieqie.wang@gmail.com]
 * @author  [in355hz@gmail.com]
 */
public class DefaultRowMapperFactory implements RowMapperFactory {

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

    private Map<String, RowMapper> rowMappers = new HashMap<String, RowMapper>();

    @Override
    public RowMapper getRowMapper(StatementMetaData modifier) {
        RowHandler rowHandler = modifier.getAnnotation(RowHandler.class);
        if (rowHandler != null) {
            if (rowHandler.rowMapper() != RowHandler.ByDefault.class) {
                try {
                    RowMapper rowMapper = rowHandler.rowMapper().newInstance();
                    if (logger.isInfoEnabled()) {
                        logger.info("using rowMapper " + rowMapper + " for " + modifier);
                    }

                    return rowMapper;
                } catch (Exception ex) {
                    throw new BeanInstantiationException(rowHandler.rowMapper(), ex.getMessage(), ex);
                }
            }
        }
        //

        Class<?> returnClassType = modifier.getMethod().getReturnType();
        Class<?> rowType = getRowType(modifier);

        // BUGFIX: SingleColumnRowMapper ?  Primitive Type 
        if (rowType.isPrimitive()) {
            rowType = ClassUtils.primitiveToWrapper(rowType);
        }

        // ?  RowMapper
        RowMapper rowMapper;

        // ?(?2Map)
        if (TypeUtils.isColumnType(rowType)) {
            if (returnClassType == Map.class) {
                rowMapper = new MapEntryColumnRowMapper(modifier, rowType);
            } else {
                rowMapper = new SingleColumnRowMapper(rowType);
            }
        }
        // Bean??????
        else {
            if (rowType == Map.class) {
                rowMapper = new ColumnMapRowMapper();
            } else if (rowType.isArray()) {
                rowMapper = new ArrayRowMapper(rowType);
            } else if ((rowType == List.class) || (rowType == Collection.class)) {
                rowMapper = new ListRowMapper(modifier);
            } else if (rowType == Set.class) {
                rowMapper = new SetRowMapper(modifier);
            } else {
                boolean checkColumns = (rowHandler == null) ? true : rowHandler.checkColumns();
                boolean checkProperties = (rowHandler == null) ? false : rowHandler.checkProperties();
                String key = rowType.getName() + "[checkColumns=" + checkColumns + "&checkProperties="
                        + checkProperties + "]";
                rowMapper = rowMappers.get(key);
                if (rowMapper == null) {
                    rowMapper = new BeanPropertyRowMapper(rowType, checkColumns, checkProperties); // jade's BeanPropertyRowMapper here
                    rowMappers.put(key, rowMapper);
                }
            }
            // DAOMaprowMapper?Map.Entry
            if (returnClassType == Map.class) {
                rowMapper = new MapEntryRowMapper(modifier, rowMapper);
            }
        }

        if (logger.isInfoEnabled()) {
            logger.info("using rowMapper " + rowMapper + " for " + modifier);
        }

        return rowMapper;
    }

    // ?
    private static Class<?> getRowType(StatementMetaData statementMetaData) {
        Class<?> returnClassType = statementMetaData.getMethod().getReturnType();
        if (Collection.class.isAssignableFrom(returnClassType)) {
            return getRowTypeFromCollectionType(statementMetaData, returnClassType);
        } else if (Map.class == returnClassType) {
            return getRowTypeFromMapType(statementMetaData, returnClassType);
        } else if (returnClassType.isArray() && returnClassType != byte[].class) {
            // , ??
            return returnClassType.getComponentType();
        }

        // DAO?
        return returnClassType;
    }

    private static Class<?> getRowTypeFromMapType(StatementMetaData modifier, Class<?> returnClassType) {
        Class<?> rowType;
        // ?  Map<K, V> 
        Class<?>[] genericTypes = modifier.getGenericReturnTypes();
        if (genericTypes.length != 2) {
            throw new IllegalArgumentException("the returned generic type '" + returnClassType.getName()
                    + "' should has two actual type parameters.");
        }
        rowType = genericTypes[1]; // ?  V 
        return rowType;
    }

    private static Class<?> getRowTypeFromCollectionType(StatementMetaData modifier, Class<?> returnClassType) {
        Class<?> rowType;
        // ?  List / Collection / Set
        if ((returnClassType != List.class) && (returnClassType != Collection.class)
                && (returnClassType != Set.class)) {
            throw new IllegalArgumentException(
                    "error collection type " + returnClassType.getName() + "; only support List, Set, Collection");
        }
        // ??
        Class<?>[] genericTypes = modifier.getGenericReturnTypes();
        if (genericTypes.length != 1) {
            throw new IllegalArgumentException("the returned generic type '" + returnClassType.getName()
                    + "' should has a actual type parameter.");
        }
        rowType = genericTypes[0];
        return rowType;
    }

}