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.bookkeeper.mledger.impl; import com.google.common.collect.ImmutableMap; import java.nio.charset.StandardCharsets; import java.util.Map; /** * Utilities for managing BookKeeper Ledgers custom metadata. */ public final class LedgerMetadataUtils { private static final String METADATA_PROPERTY_APPLICATION = "application"; private static final byte[] METADATA_PROPERTY_APPLICATION_PULSAR = "pulsar".getBytes(StandardCharsets.UTF_8); private static final String METADATA_PROPERTY_COMPONENT = "component"; private static final byte[] METADATA_PROPERTY_COMPONENT_MANAGED_LEDGER = "managed-ledger" .getBytes(StandardCharsets.UTF_8); private static final byte[] METADATA_PROPERTY_COMPONENT_COMPACTED_LEDGER = "compacted-ledger" .getBytes(StandardCharsets.UTF_8); private static final byte[] METADATA_PROPERTY_COMPONENT_SCHEMA = "schema".getBytes(StandardCharsets.UTF_8); private static final String METADATA_PROPERTY_MANAGED_LEDGER_NAME = "pulsar/managed-ledger"; private static final String METADATA_PROPERTY_CURSOR_NAME = "pulsar/cursor"; private static final String METADATA_PROPERTY_COMPACTEDTOPIC = "pulsar/compactedTopic"; private static final String METADATA_PROPERTY_COMPACTEDTO = "pulsar/compactedTo"; private static final String METADATA_PROPERTY_SCHEMAID = "pulsar/schemaId"; /** * Build base metadata for every ManagedLedger. * * @param name the name of the ledger * @return an immutable map which describes a ManagedLedger */ static Map<String, byte[]> buildBaseManagedLedgerMetadata(String name) { return ImmutableMap.of(METADATA_PROPERTY_APPLICATION, METADATA_PROPERTY_APPLICATION_PULSAR, METADATA_PROPERTY_COMPONENT, METADATA_PROPERTY_COMPONENT_MANAGED_LEDGER, METADATA_PROPERTY_MANAGED_LEDGER_NAME, name.getBytes(StandardCharsets.UTF_8)); } /** * Build additional metadata for a Cursor. * * @param name the name of the cursor * @return an immutable map which describes the cursor * @see #buildBaseManagedLedgerMetadata(java.lang.String) */ static Map<String, byte[]> buildAdditionalMetadataForCursor(String name) { return ImmutableMap.of(METADATA_PROPERTY_CURSOR_NAME, name.getBytes(StandardCharsets.UTF_8)); } /** * Build additional metadata for a CompactedLedger. * * @param compactedTopic reference to the compacted topic. * @param compactedToMessageId last mesasgeId. * @return an immutable map which describes the compacted ledger */ public static Map<String, byte[]> buildMetadataForCompactedLedger(String compactedTopic, byte[] compactedToMessageId) { return ImmutableMap.of(METADATA_PROPERTY_APPLICATION, METADATA_PROPERTY_APPLICATION_PULSAR, METADATA_PROPERTY_COMPONENT, METADATA_PROPERTY_COMPONENT_COMPACTED_LEDGER, METADATA_PROPERTY_COMPACTEDTOPIC, compactedTopic.getBytes(StandardCharsets.UTF_8), METADATA_PROPERTY_COMPACTEDTO, compactedToMessageId); } /** * Build additional metadata for a Schema * * @param schemaId id of the schema * @return an immutable map which describes the schema */ public static Map<String, byte[]> buildMetadataForSchema(String schemaId) { return ImmutableMap.of(METADATA_PROPERTY_APPLICATION, METADATA_PROPERTY_APPLICATION_PULSAR, METADATA_PROPERTY_COMPONENT, METADATA_PROPERTY_COMPONENT_SCHEMA, METADATA_PROPERTY_SCHEMAID, schemaId.getBytes(StandardCharsets.UTF_8)); } private LedgerMetadataUtils() { } }