SkipListener在chunk处理阶段抛出跳过定义的异常时触发,在chunk的读、处理、写阶段发生的异常都会触发该拦截器
SkipListener接口声明:
/*
* Copyright 2006-2007 the original author or authors.
*
* Licensed 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.springframework.batch.core;
/**
* Interface for listener to skipped items. Callbacks will be called by
* {@link Step} implementations at the appropriate time in the step lifecycle.
* Implementers of this interface should not assume that any method will be
* called immediately after an error has been encountered. Because there
* may be errors later on in processing the chunk, this listener will not be
* called until just before committing.
*
* @author Dave Syer
* @author Robert Kasanicky
*
*/
public interface SkipListener<T,S> extends StepListener {
/**
* Callback for a failure on read that is legal, so is not going to be
* re-thrown. In case transaction is rolled back and items are re-read, this
* callback will occur repeatedly for the same cause. This will only happen
* if read items are not buffered.
*
* @param t cause of the failure
*/
void onSkipInRead(Throwable t);
/**
* This item failed on write with the given exception, and a skip was called
* for.
*
* @param item the failed item
* @param t the cause of the failure
*/
void onSkipInWrite(S item, Throwable t);
/**
* This item failed on processing with the given exception, and a skip was called
* for.
*
* @param item the failed item
* @param t the cause of the failure
*/
void onSkipInProcess(T item, Throwable t);
}
SkipListener方法说明及注解定义
方法 | 方法说明 | 注解定义 |
onSkipInRead(Throwable t) | 在读阶段发生异常并且配置了异常可以跳过时触发该操作 | @OnSkipInRead |
onSkipInWrite(String item, Throwable t) | 在写阶段发生异常并且配置了异常可以跳过时触发该操作 | @OnSkipInWrite |
onSkipInProcess(String item, Throwable t) | 在处理阶段发生异常并且配置了异常可以跳过时触发该操作 | @OnSkipInProcess |
SkipListener的默认实现接口
CompositeSkipListener ---组合跳过拦截器
MulticasterBatchListener--组合策略跳过拦截器
SkipListenerSupport----跳过拦截器默认实现
自定义SkipListener实现示例:
/**
*
*/
package com.juxtapose.example.ch05.step.listener;
import org.springframework.batch.core.SkipListener;
import org.springframework.batch.core.annotation.OnSkipInProcess;
import org.springframework.batch.item.file.FlatFileParseException;
import org.springframework.jdbc.core.JdbcTemplate;
/**
* 自定义SkipListener
* @author wbw
*
*/
public class DBSkipListener implements SkipListener<String, String> {
private JdbcTemplate jdbcTemplate;
@OnSkipInProcess
public void onSkipInRead(Throwable t) {
if (t instanceof FlatFileParseException) {
jdbcTemplate.update("insert into skipbills "
+ "(line,content) values (?,?)",
((FlatFileParseException) t).getLineNumber(),
((FlatFileParseException) t).getInput());
}
}
public void onSkipInWrite(String item, Throwable t) {
}
public void onSkipInProcess(String item, Throwable t) {
}
public JdbcTemplate getJdbcTemplate() {
return jdbcTemplate;
}
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
}