Spring集成：如何顺序处理文件

我使用“int-file: inbound-channel-adapter”来加载目录中存在的文件。我喜欢按顺序处理文件：这意味着当第一个文件的处理完成时，我加载第二个文件......等等。

I see a sample https://github.com/spring-projects/spring-integration-samples/blob/master/intermediate/file-processing/src/main/java/org/springframework/integration/samples/fileprocessing/FileProcessor.java但我无法预测处理一个文件所需的时间，这取决于文件的大小。

我的源代码：

    <int-file:inbound-channel-adapter
    directory="${directory.files.local}" id="filesIn" channel="channel.filesIn">
    <int:poller fixed-delay="1000" max-messages-per-poll="1" />

</int-file:inbound-channel-adapter>

一个文件的处理过程是 file:inbound-channel-adapter--->transformer--->splitter---->http:outbound-gateway--->outbound-mail-adapter---->的处理一个文件处理完毕，那么此时，我要处理下一个文件。

我的项目配置太复杂了。 下面，我向您展示更多配置： 配置的第一部分是：

<int-sftp:inbound-channel-adapter id="sftpInbondAdapter"
    auto-startup="true" channel="receiveChannel" session-factory="sftpSessionFactory"
    local-directory="file:${directory.files.local}" remote-directory="${directory.files.remote}"
    auto-create-local-directory="true" delete-remote-files="true"
    filename-regex=".*\.txt$">
    <int:poller fixed-delay="${sftp.interval.request}"
        max-messages-per-poll="-1" />
</int-sftp:inbound-channel-adapter>
<!-- <int:poller cron="0 * 17 * * ?"></int:poller> -->

<int-file:inbound-channel-adapter
    filter="compositeFileFilter" directory="${directory.files.local}" id="filesIn"
    channel="channel.filesIn" prevent-duplicates="true">
    <int:poller fixed-delay="1000" max-messages-per-poll="1" />
</int-file:inbound-channel-adapter>

<int:transformer input-channel="channel.filesIn"
    output-channel="channel.file.router" ref="fileTransformer" method="transform" />

<int:recipient-list-router id="fileRouter"
    input-channel="channel.file.router">

    <int:recipient channel="channel.empty.files"
        selector-expression="payload.length()==0" />
    <int:recipient channel="channel.filesRejected"
        selector-expression="payload.toString().contains('rejected')" />
    <int:recipient channel="toSplitter"
        selector-expression="(payload.length()>0) and(!payload.toString().contains('rejected'))" />

</int:recipient-list-router>

然后从通道 tosplitter 中，我的程序逐行读取文件：

    <int-file:splitter input-channel="toSplitter"
    output-channel="router" requires-reply="false" />

<int:recipient-list-router id="recipentRouter"
    input-channel="router">

    <int:recipient channel="channelA"
        selector-expression="headers['file_name'].startsWith('${filenameA.prefix}')" />

    <int:recipient channel="channelB"
        selector-expression="headers['file_name'].startsWith('${filenameB.prefix}')" />

</int:recipient-list-router>

每个通道 A 和 B 应该为每条线路调用两个不同的 WAYS。 每个文件都使用异步调用 ws 代码，文件 A 如下：

<int:header-enricher input-channel="channelA"
    output-channel="channelA.withHeader">
    <int:header name="content-type" value="application/json" />
    <int:header name="key1" expression="payload.split('${line.column.separator}')[0]" />
    <int:header name="key2" expression="payload"></int:header>
</int:header-enricher>

<int:transformer input-channel="channelA.withHeader"
    output-channel="channelA.request" ref="imsiMsgTransformer"
    method="transform">
</int:transformer>


<int:channel id="channelA.request">
    <int:queue capacity="10" />

<int-http:outbound-gateway id="maspUpdatorSimChangedGateway"
    request-channel="channelA.request" 
    url="${url}"
    http-method="PUT" expected-response-type="java.lang.String"       charset="UTF-8"
    reply-timeout="${ws.reply.timeout}" reply-channel="channelA.reply">
    <int-http:uri-variable name="foo" expression="headers['key1']" />
    <int:poller fixed-delay="1000" error-channel="channelA.error"
        task-executor="executorA" />

        <int-http:request-handler-advice-chain>
        <int:retry-advice max-attempts="${ws.max.attempts}"
            recovery-channel="recovery.channelA">
            <int:fixed-back-off interval="${ws.interval.attempts}" />
        </int:retry-advice>
    </int-http:request-handler-advice-chain>

</int-http:outbound-gateway>

<int:service-activator input-channel="recovery.channelA"
    ref="updateImsiHttpResponseErrorHandler" method="handleMessage" output-channel="updateImsi.channel.error.toenricher">
</int:service-activator>

<int:service-activator input-channel="channelA.reply"
    ref="updateImsiHttpResponseMessageHandler" method="handleMessage">
    <int:poller fixed-delay="1000"></int:poller>
</int:service-activator>

在（回复通道和恢复通道）的每个激活器中，我计算文件的进度，直到文件完成，此时我应该加载第二个文件 A2 或文件 B ...等

这是默认行为，只要

1. 轮询器没有task-executor（你的没有）。
2. Only DirectChannel是（默认）用于适配器的下游 - 这意味着不QueueChannels or ExecutorChannel（即没有task-executor or <queue/>在频道上）。

在这种情况下，在当前轮询完成之前，甚至不会考虑下一次轮询 - 流程在轮询器线程上运行，并且一次只能处理一个轮询。

The fixed-delay直到当前文件完全处理完毕后才开始。

EDIT

如果需要对流程使用异步处理，则需要使用条件轮询器 http://docs.spring.io/spring-integration/reference/html/messaging-channels-section.html#conditional-pollers或者一个简单的投票跳过建议 http://docs.spring.io/spring-integration/reference/html/messaging-channels-section.html#_pollable_message_source.

你会提供一个PollSkipStrategy在文件完成之前将返回 false 的实现。

这样，后续的民意调查将被跳过，直到您做出决定。

EDIT2

像这样的东西...

/*
 * Copyright 2015 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.integration.scheduling;

/**
 * @author Gary Russell
 * @since 4.3
 *
 */
public class SimplePollSkipStrategy implements PollSkipStrategy {

    private volatile boolean skip;

    @Override
    public boolean skipPoll() {
        return this.skip;
    }

    public void skipPolls() {
        this.skip = true;
    }

    public void reset() {
        this.skip = false;
    }
}

• 将其添加为<bean/>根据您的情况。
• 将其添加到轮询器的建议链中PollSkipAdvice
• 当您想跳过投票时，请致电skipPolls().
• 当您完成文件处理后，请致电reset().