Java tutorial
/* * Licensed to CRATE Technology GmbH ("Crate") under one or more contributor * license agreements. See the NOTICE file distributed with this work for * additional information regarding copyright ownership. Crate licenses * this file to you 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. * * However, if you have executed another commercial license agreement * with Crate these terms will supersede the license and you may use the * software solely pursuant to the terms of the relevant commercial agreement. */ package io.crate.sql.tree; import com.google.common.base.Joiner; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.collect.ImmutableList; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import java.util.List; public class QualifiedName { private final List<String> parts; public static QualifiedName of(String first, String... rest) { Preconditions.checkNotNull(first, "first is null"); return new QualifiedName(ImmutableList.copyOf(Lists.asList(first, rest))); } public static QualifiedName of(Iterable<String> parts) { Preconditions.checkNotNull(parts, "parts is null"); Preconditions.checkArgument(!Iterables.isEmpty(parts), "parts is empty"); return new QualifiedName(parts); } public QualifiedName(String name) { this(ImmutableList.of(name)); } public QualifiedName(Iterable<String> parts) { Preconditions.checkNotNull(parts, "parts"); Preconditions.checkArgument(!Iterables.isEmpty(parts), "parts is empty"); this.parts = ImmutableList.copyOf(parts); } public List<String> getParts() { return parts; } @Override public String toString() { return Joiner.on('.').join(parts); } /** * For an identifier of the form "a.b.c.d", returns "a.b.c" * For an identifier of the form "a", returns absent */ public Optional<QualifiedName> getPrefix() { if (parts.size() == 1) { return Optional.absent(); } return Optional.of(QualifiedName.of(parts.subList(0, parts.size() - 1))); } public String getSuffix() { return Iterables.getLast(parts); } @Override public boolean equals(Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } QualifiedName that = (QualifiedName) o; if (!parts.equals(that.parts)) { return false; } return true; } @Override public int hashCode() { return parts.hashCode(); } }