org.mybatis.dynamic.sql.render.TableAliasCalculator Maven / Gradle / Ivy
/**
* Copyright 2016-2017 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 org.mybatis.dynamic.sql.render;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import org.mybatis.dynamic.sql.SqlTable;
public class TableAliasCalculator {
private Map aliases;
protected TableAliasCalculator(Map aliases) {
this.aliases = Objects.requireNonNull(aliases);
}
public Optional aliasForColumn(SqlTable table) {
return Optional.ofNullable(aliases.get(table));
}
public Optional aliasForTable(SqlTable table) {
return Optional.ofNullable(aliases.get(table));
}
public static TableAliasCalculator of(SqlTable table, String alias) {
Map tableAliases = new HashMap<>();
tableAliases.put(table, alias);
return of(tableAliases);
}
public static TableAliasCalculator of(Map aliases) {
return new TableAliasCalculator(aliases);
}
public static TableAliasCalculator empty() {
return of(Collections.emptyMap());
}
}