| /** |
| * 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.storm.cassandra.query; |
| |
| import java.io.Serializable; |
| import java.util.Map; |
| import org.apache.storm.tuple.ITuple; |
| |
| /** |
| * This interface may be used to retrieve a cassandra bound query either from storm config |
| * or the tuple being proceed. |
| */ |
| public interface ContextQuery extends Serializable { |
| |
| /** |
| * Resolves a cassandra bound query. |
| * |
| * @param config the storm configuration |
| * @param tuple the tuple being proceed. |
| * |
| * @return a string bound query. |
| */ |
| String resolves(Map<String, Object> config, ITuple tuple); |
| |
| /** |
| * Static implementation of {@link ContextQuery} interface. |
| */ |
| final class StaticContextQuery implements ContextQuery { |
| private final String value; |
| |
| /** |
| * Creates a new {@link StaticContextQuery} instance. |
| */ |
| public StaticContextQuery(String value) { |
| this.value = value; |
| } |
| |
| @Override |
| public String resolves(Map<String, Object> config, ITuple tuple) { |
| return value; |
| } |
| } |
| |
| /** |
| * Default {@link BoundQueryContext} implementation to retrieve a bound query |
| * identified by the provided key. |
| */ |
| final class BoundQueryContext implements ContextQuery { |
| private String key; |
| |
| public BoundQueryContext(String key) { |
| this.key = key; |
| } |
| |
| @Override |
| public String resolves(Map<String, Object> config, ITuple tuple) { |
| if (config.containsKey(key)) { |
| return (String) config.get(key); |
| } |
| |
| throw new IllegalArgumentException("Bound query '" + key + "' does not exist in configuration"); |
| } |
| } |
| |
| /** |
| * Default {@link BoundQueryNamedByFieldContext} implementation to retrieve a bound query named by |
| * the value of a specified tuple field. |
| */ |
| final class BoundQueryNamedByFieldContext implements ContextQuery { |
| |
| private String fieldName; |
| |
| public BoundQueryNamedByFieldContext(String fieldName) { |
| this.fieldName = fieldName; |
| } |
| |
| @Override |
| public String resolves(Map<String, Object> config, ITuple tuple) { |
| String name = tuple.getStringByField(fieldName); |
| if (config.containsKey(name)) { |
| return (String) config.get(name); |
| } |
| throw new IllegalArgumentException("Bound query '" + name + "' does not exist in configuration"); |
| } |
| } |
| } |