Java tutorial
/* Copyright 2013 Red Hat, Inc. and/or its affiliates. This file is part of lightblue. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ package com.redhat.lightblue.crud.mongo; import java.util.List; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.fasterxml.jackson.databind.node.JsonNodeFactory; import com.mongodb.DBCollection; import com.mongodb.DBCursor; import com.mongodb.DBObject; import com.mongodb.WriteResult; import com.redhat.lightblue.crud.CRUDOperationContext; import com.redhat.lightblue.crud.CRUDUpdateResponse; import com.redhat.lightblue.crud.ConstraintValidator; import com.redhat.lightblue.crud.CrudConstants; import com.redhat.lightblue.crud.DocCtx; import com.redhat.lightblue.crud.Operation; import com.redhat.lightblue.eval.FieldAccessRoleEvaluator; import com.redhat.lightblue.eval.Projector; import com.redhat.lightblue.eval.Updater; import com.redhat.lightblue.metadata.EntityMetadata; import com.redhat.lightblue.metadata.PredefinedFields; import com.redhat.lightblue.mongo.hystrix.FindCommand; import com.redhat.lightblue.mongo.hystrix.SaveCommand; import com.redhat.lightblue.util.Error; import com.redhat.lightblue.util.Path; /** * Non-atomic updater that evaluates the query, and updates the documents one by one. */ public class IterateAndUpdate implements DocUpdater { private static final Logger LOGGER = LoggerFactory.getLogger(IterateAndUpdate.class); private final JsonNodeFactory nodeFactory; private final ConstraintValidator validator; private final FieldAccessRoleEvaluator roleEval; private final Translator translator; private final Updater updater; private final Projector projector; private final Projector errorProjector; public IterateAndUpdate(JsonNodeFactory nodeFactory, ConstraintValidator validator, FieldAccessRoleEvaluator roleEval, Translator translator, Updater updater, Projector projector, Projector errorProjector) { this.nodeFactory = nodeFactory; this.validator = validator; this.roleEval = roleEval; this.translator = translator; this.updater = updater; this.projector = projector; this.errorProjector = errorProjector; } @Override public void update(CRUDOperationContext ctx, DBCollection collection, EntityMetadata md, CRUDUpdateResponse response, DBObject query) { LOGGER.debug("iterateUpdate: start"); LOGGER.debug("Computing the result set for {}", query); DBCursor cursor = null; int docIndex = 0; int numFailed = 0; try { cursor = new FindCommand(null, collection, query, null).execute(); LOGGER.debug("Found {} documents", cursor.count()); // read-update-write while (cursor.hasNext()) { DBObject document = cursor.next(); boolean hasErrors = false; LOGGER.debug("Retrieved doc {}", docIndex); DocCtx doc = ctx.addDocument(translator.toJson(document)); doc.setOutputDocument(doc.copy()); // From now on: doc contains the old copy, and doc.getOutputDocument contains the new copy if (updater.update(doc.getOutputDocument(), md.getFieldTreeRoot(), Path.EMPTY)) { LOGGER.debug("Document {} modified, updating", docIndex); PredefinedFields.updateArraySizes(nodeFactory, doc.getOutputDocument()); LOGGER.debug("Running constraint validations"); validator.clearErrors(); validator.validateDoc(doc.getOutputDocument()); List<Error> errors = validator.getErrors(); if (errors != null && !errors.isEmpty()) { ctx.addErrors(errors); hasErrors = true; LOGGER.debug("Doc has errors"); } errors = validator.getDocErrors().get(doc.getOutputDocument()); if (errors != null && !errors.isEmpty()) { doc.addErrors(errors); hasErrors = true; LOGGER.debug("Doc has data errors"); } if (!hasErrors) { List<Path> paths = roleEval.getInaccessibleFields_Update(doc.getOutputDocument(), doc); LOGGER.debug("Inaccesible fields during update={}" + paths); if (paths != null && !paths.isEmpty()) { doc.addError(Error.get("update", CrudConstants.ERR_NO_FIELD_UPDATE_ACCESS, paths.toString())); hasErrors = true; } } if (!hasErrors) { try { DBObject updatedObject = translator.toBson(doc.getOutputDocument()); translator.addInvisibleFields(document, updatedObject, md); WriteResult result = new SaveCommand(null, collection, updatedObject).execute(); doc.setOperationPerformed(Operation.UPDATE); LOGGER.debug("Number of rows affected : ", result.getN()); } catch (Exception e) { LOGGER.warn("Update exception for document {}: {}", docIndex, e); doc.addError(Error.get(MongoCrudConstants.ERR_UPDATE_ERROR, e.toString())); hasErrors = true; } } } else { LOGGER.debug("Document {} was not modified", docIndex); } if (hasErrors) { LOGGER.debug("Document {} has errors", docIndex); numFailed++; doc.setOutputDocument(errorProjector.project(doc.getOutputDocument(), nodeFactory)); } else { if (projector != null) { LOGGER.debug("Projecting document {}", docIndex); doc.setOutputDocument(projector.project(doc.getOutputDocument(), nodeFactory)); } } docIndex++; } } finally { if (cursor != null) { cursor.close(); } } response.setNumUpdated(docIndex); response.setNumFailed(numFailed); } }