| /* |
| * 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.pig; |
| |
| import org.apache.hadoop.mapreduce.Job; |
| import java.io.IOException; |
| |
| /** |
| * Convenience class to extend when decorating a class that extends LoadFunc and |
| * implements LoadMetadata. |
| */ |
| public class LoadFuncMetadataWrapper extends LoadFuncWrapper implements LoadMetadata { |
| |
| private LoadMetadata loadMetadata; |
| |
| protected LoadFuncMetadataWrapper() { |
| super(); |
| } |
| |
| /** |
| * The wrapped LoadMetadata object must be set before method calls are made on this object. |
| * Typically, this is done with via constructor, but often times the wrapped object can |
| * not be properly initialized until later in the lifecycle of the wrapper object. |
| * @param loadFunc |
| */ |
| protected void setLoadFunc(LoadMetadata loadFunc) { |
| super.setLoadFunc((LoadFunc)loadFunc); |
| this.loadMetadata = loadFunc; |
| } |
| |
| @Override |
| public ResourceSchema getSchema(String location, Job job) throws IOException { |
| return loadMetadata().getSchema(location, job); |
| } |
| |
| @Override |
| public ResourceStatistics getStatistics(String location, Job job) throws IOException { |
| return loadMetadata().getStatistics(location, job); |
| } |
| |
| @Override |
| public String[] getPartitionKeys(String location, Job job) throws IOException { |
| return loadMetadata().getPartitionKeys(location, job); |
| } |
| |
| @Override |
| public void setPartitionFilter(Expression partitionFilter) throws IOException { |
| loadMetadata().setPartitionFilter(partitionFilter); |
| } |
| |
| private LoadMetadata loadMetadata() { |
| if (this.loadMetadata == null) { |
| throw new IllegalArgumentException("Method calls can not be made on the " + |
| "LoadFuncMetadataWrapper object before the wrapped LoadMetadata object has been " |
| + "set. Failed on method call " + getMethodName(1)); |
| } |
| return loadMetadata; |
| } |
| |
| } |