001/* 002 * Copyright 2006-2013 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.batch.core.partition.support; 018 019import java.io.IOException; 020import java.util.HashMap; 021import java.util.Map; 022 023import org.springframework.batch.item.ExecutionContext; 024import org.springframework.core.io.Resource; 025import org.springframework.util.Assert; 026 027/** 028 * Implementation of {@link Partitioner} that locates multiple resources and 029 * associates their file names with execution context keys. Creates an 030 * {@link ExecutionContext} per resource, and labels them as 031 * <code>{partition0, partition1, ..., partitionN}</code>. The grid size is 032 * ignored. 033 * 034 * @author Dave Syer 035 * @since 2.0 036 */ 037public class MultiResourcePartitioner implements Partitioner { 038 039 private static final String DEFAULT_KEY_NAME = "fileName"; 040 041 private static final String PARTITION_KEY = "partition"; 042 043 private Resource[] resources = new Resource[0]; 044 045 private String keyName = DEFAULT_KEY_NAME; 046 047 /** 048 * The resources to assign to each partition. In Spring configuration you 049 * can use a pattern to select multiple resources. 050 * @param resources the resources to use 051 */ 052 public void setResources(Resource[] resources) { 053 this.resources = resources; 054 } 055 056 /** 057 * The name of the key for the file name in each {@link ExecutionContext}. 058 * Defaults to "fileName". 059 * @param keyName the value of the key 060 */ 061 public void setKeyName(String keyName) { 062 this.keyName = keyName; 063 } 064 065 /** 066 * Assign the filename of each of the injected resources to an 067 * {@link ExecutionContext}. 068 * 069 * @see Partitioner#partition(int) 070 */ 071 @Override 072 public Map<String, ExecutionContext> partition(int gridSize) { 073 Map<String, ExecutionContext> map = new HashMap<String, ExecutionContext>(gridSize); 074 int i = 0; 075 for (Resource resource : resources) { 076 ExecutionContext context = new ExecutionContext(); 077 Assert.state(resource.exists(), "Resource does not exist: "+resource); 078 try { 079 context.putString(keyName, resource.getURL().toExternalForm()); 080 } 081 catch (IOException e) { 082 throw new IllegalArgumentException("File could not be located for: "+resource, e); 083 } 084 map.put(PARTITION_KEY + i, context); 085 i++; 086 } 087 return map; 088 } 089 090}