Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF 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. */ package org.apache.sling.nosql.couchbase.resourceprovider.impl; import static com.couchbase.client.java.query.Select.select; import static com.couchbase.client.java.query.dsl.Expression.s; import static com.couchbase.client.java.query.dsl.Expression.x; import java.util.Iterator; import java.util.regex.Pattern; import org.apache.commons.lang3.StringUtils; import org.apache.sling.api.resource.LoginException; import org.apache.sling.api.resource.ResourceUtil; import org.apache.sling.nosql.couchbase.client.CouchbaseClient; import org.apache.sling.nosql.couchbase.client.CouchbaseKey; import org.apache.sling.nosql.generic.adapter.AbstractNoSqlAdapter; import org.apache.sling.nosql.generic.adapter.MultiValueMode; import org.apache.sling.nosql.generic.adapter.NoSqlData; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.couchbase.client.java.Bucket; import com.couchbase.client.java.document.JsonDocument; import com.couchbase.client.java.document.json.JsonObject; import com.couchbase.client.java.error.DocumentAlreadyExistsException; import com.couchbase.client.java.query.N1qlParams; import com.couchbase.client.java.query.N1qlQuery; import com.couchbase.client.java.query.N1qlQueryResult; import com.couchbase.client.java.query.N1qlQueryRow; import com.couchbase.client.java.query.consistency.ScanConsistency; /** * {@link org.apache.sling.nosql.generic.adapter.NoSqlAdapter} implementation for Couchbase. */ public final class CouchbaseNoSqlAdapter extends AbstractNoSqlAdapter { private static final String PN_PATH = "path"; private static final String PN_PARENT_PATH = "parentPath"; private static final String PN_DATA = "data"; private final CouchbaseClient couchbaseClient; private final String cacheKeyPrefix; private static final N1qlParams N1QL_PARAMS = N1qlParams.build().consistency(ScanConsistency.REQUEST_PLUS); private static final Logger log = LoggerFactory.getLogger(CouchbaseNoSqlAdapter.class); public CouchbaseNoSqlAdapter(CouchbaseClient couchbaseClient, String cacheKeyPrefix) { this.couchbaseClient = couchbaseClient; this.cacheKeyPrefix = cacheKeyPrefix; } @Override public boolean validPath(String path) { return (couchbaseClient != null && couchbaseClient.isEnabled()); } @Override public NoSqlData get(String path) { Bucket bucket = couchbaseClient.getBucket(); String cacheKey = CouchbaseKey.build(path, cacheKeyPrefix); JsonDocument doc = bucket.get(cacheKey); if (doc == null) { return null; } else { JsonObject data = doc.content().getObject(PN_DATA); if (data == null) { return null; } else { return new NoSqlData(path, data.toMap(), MultiValueMode.LISTS); } } } @Override public Iterator<NoSqlData> getChildren(String parentPath) { Bucket bucket = couchbaseClient.getBucket(); // fetch all direct children of this path N1qlQuery query = N1qlQuery.simple( select("*").from(couchbaseClient.getBucketName()).where(x(PN_PARENT_PATH).eq(s(parentPath))), N1QL_PARAMS); N1qlQueryResult queryResult = bucket.query(query); handleQueryError(queryResult); final Iterator<N1qlQueryRow> results = queryResult.iterator(); return new Iterator<NoSqlData>() { @Override public boolean hasNext() { return results.hasNext(); } @Override public NoSqlData next() { JsonObject item = results.next().value(); JsonObject envelope = item.getObject(couchbaseClient.getBucketName()); String path = envelope.getString(PN_PATH); JsonObject data = envelope.getObject(PN_DATA); return new NoSqlData(path, data.toMap(), MultiValueMode.LISTS); } @Override public void remove() { throw new UnsupportedOperationException(); } }; } @Override public boolean store(NoSqlData data) { Bucket bucket = couchbaseClient.getBucket(); String cacheKey = CouchbaseKey.build(data.getPath(), cacheKeyPrefix); JsonObject envelope = JsonObject.create(); envelope.put(PN_PATH, data.getPath()); envelope.put(PN_DATA, JsonObject.from(data.getProperties(MultiValueMode.LISTS))); // for list-children query efficiency store parent path as well String parentPath = ResourceUtil.getParent(data.getPath()); if (parentPath != null) { envelope.put(PN_PARENT_PATH, parentPath); } JsonDocument doc = JsonDocument.create(cacheKey, envelope); try { bucket.insert(doc); return true; // created } catch (DocumentAlreadyExistsException ex) { bucket.upsert(doc); return false; // updated } } @Override public boolean deleteRecursive(String path) { Bucket bucket = couchbaseClient.getBucket(); // fetch all descendants and self for deletion Pattern descendantsAndSelf = Pattern.compile("^" + path + "(/.+)?$"); N1qlQuery query = N1qlQuery.simple(select("*").from(couchbaseClient.getBucketName()) .where("REGEXP_LIKE(`" + PN_PATH + "`, '" + descendantsAndSelf.pattern() + "')"), N1QL_PARAMS); N1qlQueryResult queryResult = bucket.query(query); handleQueryError(queryResult); final Iterator<N1qlQueryRow> results = queryResult.iterator(); boolean deletedAny = false; while (results.hasNext()) { JsonObject item = results.next().value(); JsonObject envelope = item.getObject(couchbaseClient.getBucketName()); String itemPath = envelope.getString(PN_PATH); String itemCacheKey = CouchbaseKey.build(itemPath, cacheKeyPrefix); bucket.remove(itemCacheKey); deletedAny = true; } return deletedAny; } private void handleQueryError(N1qlQueryResult queryResult) { if (!queryResult.parseSuccess()) { throw new RuntimeException( "Couchbase query parsing error: " + StringUtils.join(queryResult.errors(), "\n")); } if (!queryResult.finalSuccess()) { throw new RuntimeException("Couchbase query error: " + StringUtils.join(queryResult.errors(), "\n")); } } @Override public void checkConnection() throws LoginException { // try to access root element to check connection try { Bucket bucket = couchbaseClient.getBucket(); String cacheKey = CouchbaseKey.build("/", cacheKeyPrefix); bucket.exists(cacheKey); } catch (Throwable ex) { throw new LoginException(ex); } } @Override public void createIndexDefinitions() { // make sure primary index and index on parentPath is present - ignore error if it is already present try { Bucket bucket = couchbaseClient.getBucket(); bucket.query(N1qlQuery.simple("CREATE PRIMARY INDEX ON `" + couchbaseClient.getBucketName() + "`")); bucket.query(N1qlQuery.simple("CREATE INDEX " + PN_PARENT_PATH + " ON `" + couchbaseClient.getBucketName() + "`(" + PN_PARENT_PATH + ")")); } catch (Throwable ex) { log.debug("Unable to create/validate couchbase index definitions: " + ex.getMessage(), ex); } } }