001/* 002 * Copyright 2006-2007 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.repeat.context; 018 019import java.util.concurrent.atomic.AtomicInteger; 020 021import org.springframework.batch.repeat.RepeatContext; 022import org.springframework.util.Assert; 023 024/** 025 * Helper class for policies that need to count the number of occurrences of 026 * some event (e.g. an exception type in the context) in the scope of a batch. 027 * The value of the counter can be stored between batches in a nested context, 028 * so that the termination decision is based on the aggregate of a number of 029 * sibling batches. 030 * 031 * @author Dave Syer 032 * 033 */ 034public class RepeatContextCounter { 035 036 final private String countKey; 037 038 /** 039 * Flag to indicate whether the count is stored at the level of the parent 040 * context, or just local to the current context. Default value is false. 041 */ 042 final private boolean useParent; 043 044 final private RepeatContext context; 045 046 /** 047 * Increment the counter. 048 * 049 * @param delta the amount by which to increment the counter. 050 */ 051 final public void increment(int delta) { 052 AtomicInteger count = getCounter(); 053 count.addAndGet(delta); 054 } 055 056 /** 057 * Increment by 1. 058 */ 059 final public void increment() { 060 increment(1); 061 } 062 063 /** 064 * Convenience constructor with useParent=false. 065 * @param context the current context. 066 * @param countKey the key to use to store the counter in the context. 067 */ 068 public RepeatContextCounter(RepeatContext context, String countKey) { 069 this(context, countKey, false); 070 } 071 072 /** 073 * Construct a new {@link RepeatContextCounter}. 074 * 075 * @param context the current context. 076 * @param countKey the key to use to store the counter in the context. 077 * @param useParent true if the counter is to be shared between siblings. 078 * The state will be stored in the parent of the context (if it exists) 079 * instead of the context itself. 080 */ 081 public RepeatContextCounter(RepeatContext context, String countKey, boolean useParent) { 082 083 super(); 084 085 Assert.notNull(context, "The context must be provided to initialize a counter"); 086 087 this.countKey = countKey; 088 this.useParent = useParent; 089 090 RepeatContext parent = context.getParent(); 091 092 if (this.useParent && parent != null) { 093 this.context = parent; 094 } 095 else { 096 this.context = context; 097 } 098 if (!this.context.hasAttribute(countKey)) { 099 this.context.setAttribute(countKey, new AtomicInteger()); 100 } 101 102 } 103 104 /** 105 * @return the current value of the counter 106 */ 107 public int getCount() { 108 return getCounter().intValue(); 109 } 110 111 private AtomicInteger getCounter() { 112 return ((AtomicInteger) context.getAttribute(countKey)); 113 } 114 115}