Java tutorial
/* * Copyright 2008-present MongoDB, Inc. * * 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.mongodb; import com.mongodb.annotations.Immutable; import org.bson.codecs.pojo.annotations.BsonCreator; import org.bson.codecs.pojo.annotations.BsonIgnore; import org.bson.codecs.pojo.annotations.BsonProperty; import java.util.HashSet; import java.util.Set; import static com.mongodb.assertions.Assertions.isTrueArgument; import static com.mongodb.assertions.Assertions.notNull; import static java.util.Arrays.asList; /** * A MongoDB namespace, which includes a database name and collection name. * * @since 3.0 */ @Immutable public final class MongoNamespace { public static final String COMMAND_COLLECTION_NAME = "$cmd"; private static final Set<Character> PROHIBITED_CHARACTERS_IN_DATABASE_NAME = new HashSet<Character>( asList('\0', '/', '\\', ' ', '"', '.')); private final String databaseName; private final String collectionName; @BsonIgnore private final String fullName; // cache to avoid repeated string building /** * Check the validity of the given database name. A valid database name is non-null, non-empty, and does not contain any of the * following characters: {@code '\0', '/', '\\', ' ', '"', '.'}. The server may impose additional restrictions on database names. * * @param databaseName the database name * @throws IllegalArgumentException if the database name is invalid * @since 3.4 * @mongodb.driver.manual reference/limits/#naming-restrictions Naming Restrictions */ public static void checkDatabaseNameValidity(final String databaseName) { notNull("databaseName", databaseName); isTrueArgument("databaseName is not empty", !databaseName.isEmpty()); for (int i = 0; i < databaseName.length(); i++) { isTrueArgument("databaseName does not contain '" + databaseName.charAt(i) + "'", !PROHIBITED_CHARACTERS_IN_DATABASE_NAME.contains(databaseName.charAt(i))); } } /** * Check the validity of the given collection name. A valid collection name is non-null and non-empty. The server may impose * additional restrictions on collection names. * * @param collectionName the collection name * @throws IllegalArgumentException if the collection name is invalid * @since 3.4 * @mongodb.driver.manual reference/limits/#naming-restrictions Naming Restrictions */ public static void checkCollectionNameValidity(final String collectionName) { notNull("collectionName", collectionName); isTrueArgument("collectionName is not empty", !collectionName.isEmpty()); } /** * Construct an instance for the given full name. The database name is the string preceding the first {@code "."} character. * * @param fullName the non-null full namespace * @see #checkDatabaseNameValidity(String) * @see #checkCollectionNameValidity(String) */ public MongoNamespace(final String fullName) { notNull("fullName", fullName); this.fullName = fullName; this.databaseName = getDatatabaseNameFromFullName(fullName); this.collectionName = getCollectionNameFullName(fullName); checkDatabaseNameValidity(databaseName); checkCollectionNameValidity(collectionName); } /** * Construct an instance from the given database name and collection name. * * @param databaseName the valid database name * @param collectionName the valid collection name * @see #checkDatabaseNameValidity(String) * @see #checkCollectionNameValidity(String) */ @BsonCreator public MongoNamespace(@BsonProperty("db") final String databaseName, @BsonProperty("coll") final String collectionName) { checkDatabaseNameValidity(databaseName); checkCollectionNameValidity(collectionName); this.databaseName = databaseName; this.collectionName = collectionName; this.fullName = databaseName + '.' + collectionName; } /** * Gets the database name. * * @return the database name */ @BsonProperty("db") public String getDatabaseName() { return databaseName; } /** * Gets the collection name. * * @return the collection name */ @BsonProperty("coll") public String getCollectionName() { return collectionName; } /** * Gets the full name, which is the database name and the collection name, separated by a period. * * @return the full name */ public String getFullName() { return fullName; } @Override public boolean equals(final Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } MongoNamespace that = (MongoNamespace) o; if (!collectionName.equals(that.collectionName)) { return false; } if (!databaseName.equals(that.databaseName)) { return false; } return true; } /** * Returns the standard MongoDB representation of a namespace, which is {@code <database>.<collection>}. * * @return string representation of the namespace. */ @Override public String toString() { return fullName; } @Override public int hashCode() { int result = databaseName.hashCode(); result = 31 * result + (collectionName.hashCode()); return result; } private static String getCollectionNameFullName(final String namespace) { int firstDot = namespace.indexOf('.'); if (firstDot == -1) { return namespace; } return namespace.substring(firstDot + 1); } private static String getDatatabaseNameFromFullName(final String namespace) { int firstDot = namespace.indexOf('.'); if (firstDot == -1) { return ""; } return namespace.substring(0, firstDot); } }