Java tutorial
/* * 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 com.facebook.presto.sql.tree; import com.google.common.base.Joiner; import com.google.common.collect.ImmutableList; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import java.util.List; import java.util.Optional; import static com.google.common.base.Preconditions.checkArgument; import static com.google.common.collect.Iterables.isEmpty; import static com.google.common.collect.Iterables.transform; import static java.util.Locale.ENGLISH; import static java.util.Objects.requireNonNull; public class QualifiedName { private final List<String> parts; private final List<String> originalParts; public static QualifiedName of(String first, String... rest) { requireNonNull(first, "first is null"); return new QualifiedName(ImmutableList.copyOf(Lists.asList(first, rest))); } public QualifiedName(String name) { this(ImmutableList.of(name)); } public QualifiedName(String name, boolean caseSensitive) { this(ImmutableList.of(name), caseSensitive); } public QualifiedName(Iterable<String> parts) { this(parts, false); } public QualifiedName(Iterable<String> parts, boolean caseSensitive) { requireNonNull(parts, "parts is null"); checkArgument(!isEmpty(parts), "parts is empty"); if (caseSensitive) { this.parts = ImmutableList.copyOf(parts); this.originalParts = this.parts; } else { this.parts = ImmutableList.copyOf(transform(parts, part -> part.toLowerCase(ENGLISH))); this.originalParts = ImmutableList.copyOf(parts); } } public List<String> getParts() { return parts; } public List<String> getOriginalParts() { return originalParts; } @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.empty(); } return Optional.of(new QualifiedName(parts.subList(0, parts.size() - 1))); } public boolean hasSuffix(QualifiedName suffix) { if (parts.size() < suffix.getParts().size()) { return false; } int start = parts.size() - suffix.getParts().size(); return parts.subList(start, parts.size()).equals(suffix.getParts()); } 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; } return parts.equals(((QualifiedName) o).parts); } @Override public int hashCode() { return parts.hashCode(); } }