net.hasor.db.jdbc.mapper.ColumnMapRowMapper Maven / Gradle / Ivy
/*
* Copyright 2002-2009 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 net.hasor.db.jdbc.mapper;
import net.hasor.db.jdbc.JdbcOperations;
import net.hasor.db.jdbc.RowMapper;
import net.hasor.db.types.TypeHandlerRegistry;
import net.hasor.utils.ref.LinkedCaseInsensitiveMap;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* {@link RowMapper} implementation that creates a java.util.Map
* for each row, representing all columns as key-value pairs: one
* entry for each column, with the column name as key.
*
* The Map implementation to use and the key to use for each column
* in the column Map can be customized through overriding
* {@link #createColumnMap} and {@link #getColumnKey}, respectively.
*
*
Note: By default, ColumnMapRowMapper will try to build a linked Map
* with case-insensitive keys, to preserve column order as well as allow any
* casing to be used for column names. This requires Commons Collections on the
* classpath (which will be autodetected). Else, the fallback is a standard linked
* HashMap, which will still preserve column order but requires the application
* to specify the column names in the same casing as exposed by the driver.
*
* @author Juergen Hoeller
* @since 1.2
* @see JdbcOperations#queryForList(String)
* @see JdbcOperations#queryForMap(String)
*/
public class ColumnMapRowMapper extends AbstractRowMapper> {
private final boolean caseInsensitive;
public ColumnMapRowMapper() {
this(true, TypeHandlerRegistry.DEFAULT);
}
public ColumnMapRowMapper(TypeHandlerRegistry typeHandler) {
this(true, typeHandler);
}
public ColumnMapRowMapper(boolean caseInsensitive) {
this(caseInsensitive, TypeHandlerRegistry.DEFAULT);
}
public ColumnMapRowMapper(boolean caseInsensitive, TypeHandlerRegistry typeHandler) {
super(typeHandler);
this.caseInsensitive = caseInsensitive;
}
public boolean isCaseInsensitive() {
return this.caseInsensitive;
}
@Override
public final Map mapRow(final ResultSet rs, final int rowNum) throws SQLException {
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
Map mapOfColValues = this.createColumnMap(columnCount);
for (int i = 1; i <= columnCount; i++) {
String key = this.getColumnKey(ColumnMapRowMapper.lookupColumnName(rsmd, i));
Object obj = this.getColumnValue(rs, i);
if (!mapOfColValues.containsKey(key)) {
mapOfColValues.put(key, obj);
}
}
return mapOfColValues;
}
private static String lookupColumnName(final ResultSetMetaData resultSetMetaData, final int columnIndex) throws SQLException {
String name = resultSetMetaData.getColumnLabel(columnIndex);
if (name == null || name.length() < 1) {
name = resultSetMetaData.getColumnName(columnIndex);
}
return name;
}
/**取得指定列的值*/
protected Object getColumnValue(final ResultSet rs, final int index) throws SQLException {
return getResultSetValue(rs, index);
}
/**讲列名转换为合理的格式。*/
protected String getColumnKey(final String columnName) {
return columnName;
}
/**创建一个 Map 用于存放数据*/
protected Map createColumnMap(final int columnCount) {
if (this.caseInsensitive) {
return new LinkedCaseInsensitiveMap<>(columnCount);
} else {
return new LinkedHashMap<>();
}
}
}