scriptella.util.ColumnsMap Maven / Gradle / Ivy
/*
* Copyright 2006-2012 The Scriptella Project Team.
*
* 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 scriptella.util;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
/**
* Represents a map of columns accessible by name and index.
* This class is useful for queries producing results similar to ResultSet.
*
* @author Fyodor Kupolov
* @version 1.0
*/
public class ColumnsMap {
private Map map;
/**
* Registers column to for later lookup.
*
* @param name column name.
* @param index positive column index.
* @throws IllegalArgumentException if index has illegal value
*/
public void registerColumn(String name, int index) throws IllegalArgumentException {
if (index <= 0) {
throw new IllegalArgumentException("Index must be positive integer");
}
if (map == null) {
map = CollectionUtils.newCaseInsensitiveAsciiMap();
}
map.put(name, index);
}
/**
* Finds column index by name.
*
* @param name column name.
* @return column index, or null if column not found.
*/
public Integer find(String name) {
if (name == null) {
throw new IllegalArgumentException("Parameter name cannot be null");
}
Integer index = map == null ? null : map.get(name);
//If name is not a column name and is integer
if (index == null && StringUtils.isDecimalInt(name)) {
index = Integer.valueOf(name); //Try to parse name as index
}
return index;
}
/**
* Converts this mapping to index->name column map.
* @return index->name column map.
*/
public Map asIndexNameMap() {
if (map==null) {
return Collections.emptyMap();
}
Map m = new HashMap();
for (Map.Entry e : map.entrySet()) {
m.put(e.getValue(), e.getKey());
}
return m;
}
}