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.lang.Nullable; import org.bson.BsonDocument; import static com.mongodb.DBObjects.toDBObject; import static com.mongodb.assertions.Assertions.notNull; /** * A simple wrapper to hold the result of a command. All the fields from the response document have been added to this result. * * @mongodb.driver.manual reference/command/ Database Commands */ public class CommandResult extends BasicDBObject { private static final long serialVersionUID = 5907909423864204060L; private final BsonDocument response; private final ServerAddress address; CommandResult(final BsonDocument response) { this(response, null); } CommandResult(final BsonDocument response, @Nullable final ServerAddress address) { this.address = address; this.response = notNull("response", response); putAll(toDBObject(response)); } /** * Gets the "ok" field, which is whether this command executed correctly or not. * * @return true if the command executed without error. */ public boolean ok() { Object okValue = get("ok"); if (okValue instanceof Boolean) { return (Boolean) okValue; } else if (okValue instanceof Number) { return ((Number) okValue).intValue() == 1; } else { return false; } } /** * Gets the error message associated with a failed command. * * @return The error message or null */ @Nullable public String getErrorMessage() { Object foo = get("errmsg"); if (foo == null) { return null; } return foo.toString(); } /** * Utility method to create an exception from a failed command. * * @return The mongo exception, or null if the command was successful. */ @Nullable public MongoException getException() { if (!ok()) { return createException(); } return null; } /** * Throws a {@code CommandFailureException} if the command failed. Otherwise, returns normally. * * @throws MongoException with the exception from the failed command * @see #ok() */ public void throwOnError() { if (!ok()) { throw createException(); } } private MongoException createException() { return new MongoCommandException(response, address); } }