Java tutorial
/* * 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 com.sinosoft.one.data.jade.rowmapper; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import com.sinosoft.one.data.jade.annotation.KeyColumnOfMap; import com.sinosoft.one.data.jade.statement.StatementMetaData; import org.apache.commons.lang.StringUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.dao.TypeMismatchDataAccessException; import org.springframework.jdbc.core.RowMapper; import org.springframework.jdbc.support.JdbcUtils; /** * SQL???????key?key-value * * @author [qieqie.wang@gmail.com] * @author [in355hz@gmail.com] * */ public class MapEntryRowMapper implements RowMapper { private static Log logger = LogFactory.getLog(MapEntryRowMapper.class); private final RowMapper mapper; private String keyColumn; private int keyColumnIndex = 1; private Class<?> keyType; private StatementMetaData modifier; public MapEntryRowMapper(StatementMetaData modifier, RowMapper mapper) { this.modifier = modifier; Class<?>[] genericTypes = modifier.getGenericReturnTypes(); if (genericTypes.length < 2) { throw new IllegalArgumentException( "please set map generic parameters in method: " + modifier.getMethod()); } KeyColumnOfMap mapKey = modifier.getAnnotation(KeyColumnOfMap.class); this.keyColumn = (mapKey != null) ? mapKey.value() : null; this.keyType = genericTypes[0]; this.mapper = mapper; } public Object mapRow(ResultSet rs, int rowNum) throws SQLException { if (rowNum == 0) { if (StringUtils.isNotEmpty(keyColumn)) { keyColumnIndex = rs.findColumn(keyColumn); if (keyColumnIndex <= 0) { throw new IllegalArgumentException( String.format("wrong key name %s for method: %s ", keyColumn, modifier.getMethod())); } keyColumn = null; } if (logger.isDebugEnabled()) { logger.debug(String.format("keyIndex=%s; for method: %s ", keyColumnIndex, modifier.getMethod())); } } // JDBC ResultSet ? Key Object key = JdbcUtils.getResultSetValue(rs, keyColumnIndex, keyType); if (key != null && !keyType.isInstance(key)) { ResultSetMetaData rsmd = rs.getMetaData(); throw new TypeMismatchDataAccessException( // NL "Type mismatch affecting row number " + rowNum + " and column type '" + rsmd.getColumnTypeName(keyColumnIndex) + "' expected type is '" + keyType + "'"); } return new MapEntryImpl<Object, Object>(key, mapper.mapRow(rs, rowNum)); } }