如何让Camel FTP在CronScheduledRoutePolicy触发路由后仅轮询一次文件

Hey there! Let's get your Camel FTP → SharePoint monthly report workflow sorted out—you've already got a great foundation with the filename filter and cron schedule, so let's tie it all together properly.

1. Validate Your Existing FTP & Scheduling Config #

First, let's formalize the setup you've started, filling in logical gaps for clarity:

<!-- Filename filter for ACE reports in CSREPORT folder -->
<bean id="aceReportFileNameFilter" class="org.apache.camel.component.file.GenericFileFilter">
    <method name="accept">
        <argument type="org.apache.camel.component.file.GenericFile">
            <simple>${file:name} regex 'ACE_Report_.*\.pdf'</simple>
        </argument>
    </method>
</bean>

<!-- Matching filter for your second report (e.g., BCD Report) -->
<bean id="bcdReportFileNameFilter" class="org.apache.camel.component.file.GenericFileFilter">
    <method name="accept">
        <argument type="org.apache.camel.component.file.GenericFile">
            <simple>${file:name} regex 'BCD_Report_.*\.xlsx'</simple>
        </argument>
    </method>
</bean>

<!-- Cron Schedule: Trigger twice monthly (example: 1st and 15th at 2 AM) -->
<bean id="monthlyTriggerPolicy" class="org.apache.camel.routepolicy.quartz.CronScheduledRoutePolicy">
    <property name="routeStartCron" value="0 0 2 1,15 * ?"/> <!-- Adjust to your desired time/dates -->
    <property name="routeStartRepeatCount" value="-1"/> <!-- Repeat indefinitely -->
</bean>

<!-- Base Camel Context with FTP Routes -->
<camelContext xmlns="http://camel.apache.org/schema/spring">
    <!-- Route for ACE Report -->
    <route id="ftp-download-ace-report" routePolicyRef="monthlyTriggerPolicy">
        <from uri="ftp://your-ftp-username@ftp.your-domain.com/CSREPORT?password=your-ftp-password&amp;filter=#aceReportFileNameFilter&amp;delete=false"/>
        <!-- SharePoint upload step will go here -->
    </route>

    <!-- Route for Second Report -->
    <route id="ftp-download-second-report" routePolicyRef="monthlyTriggerPolicy">
        <from uri="ftp://your-ftp-username@ftp.your-domain.com/CSREPORT?password=your-ftp-password&amp;filter=#bcdReportFileNameFilter&amp;delete=false"/>
        <!-- SharePoint upload step will go here -->
    </route>
</camelContext>

Quick notes: Tweak the cron expression to match your exact trigger times (use a cron tester if needed), and set delete=true only if you want to remove files from FTP post-download.

2. Add SharePoint Upload Logic #

Next, integrate Camel's SharePoint component to push downloaded files to your site. We'll use SharePoint Online for this example:

Step 1: Add Dependency (Maven) #

Add this to your pom.xml to pull in the SharePoint component (match your Camel version):

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-sharepoint-online</artifactId>
    <version>4.3.0</version> <!-- Use your Camel version -->
</dependency>

Step 2: Configure SharePoint Authentication #

Add a bean for secure SharePoint access (store credentials in environment variables/properties for production!):

<bean id="sharepointAuth" class="org.apache.camel.component.sharepoint.online.auth.SharePointOnlineAuthentication">
    <property name="clientId" value="your-sharepoint-client-id"/>
    <property name="clientSecret" value="your-sharepoint-client-secret"/>
    <property name="tenantId" value="your-azure-tenant-id"/>
    <property name="siteUrl" value="https://your-tenant.sharepoint.com/sites/YourReportSite"/>
</bean>

Step 3: Update Routes to Include Upload #

Modify your FTP routes to add the SharePoint upload step:

<route id="ftp-download-ace-report" routePolicyRef="monthlyTriggerPolicy">
    <from uri="ftp://your-ftp-username@ftp.your-domain.com/CSREPORT?password=your-ftp-password&amp;filter=#aceReportFileNameFilter&amp;delete=false"/>
    <!-- Upload to target SharePoint document library -->
    <to uri="sharepoint-online://sites/YourReportSite/Shared%20Documents/MonthlyReports?authentication=#sharepointAuth&amp;operation=create"/>
    <log message="Successfully uploaded ACE Report to SharePoint: ${file:name}"/>
</route>

Replace Shared%20Documents/MonthlyReports with your actual document library path (URL-encode spaces!).

3. Critical Reliability Tips #

• Error Handling: Add a retry/alert block to handle FTP/SharePoint failures:

  <onException>
      <exception>java.io.IOException</exception>
      <redeliveryPolicy maximumRedeliveries="3" redeliveryDelay="30000"/> <!-- Retry 3x every 30s -->
      <log message="Failed to process file ${file:name}: ${exception.message}"/>
      <to uri="file://./local-error-folder"/> <!-- Store failed files locally -->
  </onException>
  

• Idempotency: Avoid re-downloading the same file by adding an idempotent repository:

  <from uri="ftp://...&amp;idempotent=true&amp;idempotentRepository=#fileIdempotentRepo"/>
  <bean id="fileIdempotentRepo" class="org.apache.camel.processor.idempotent.FileIdempotentRepository">
      <property name="fileStore" value="./idempotent-store"/>
  </bean>
  

• Test First: Use a temporary cron (e.g., 0 */5 * * * ? to run every 5 minutes) to test the full workflow before relying on the monthly trigger.

4. Troubleshooting Common Hiccups #

• FTP Timeouts: Add passiveMode=true to your FTP URI if your server requires passive mode.
• SharePoint Permissions: Ensure your client ID/secret has Site.ReadWrite.All or specific library permissions in Azure AD.
• Filter Mismatches: Double-check your regex in the filename filter—case sensitivity matters!

内容的提问来源于stack exchange，提问作者RKA