FTP Outbound Gateway

FTP 出站网关提供了一组有限的命令来与一个远程 FTP 或 FTPS 服务器进行交互。支持的命令包括：

The FTP outbound gateway provides a limited set of commands to interact with a remote FTP or FTPS server. The supported commands are:

  • ls (list files)

  • nlst (list file names)

  • get (retrieve file)

  • mget (retrieve file(s))

  • rm (remove file(s))

  • mv (move/rename file)

  • put (send file)

  • mput (send multiple files)

Using the ls Command

ls 列出远程文件并支持以下选项：

ls lists remote files and supports the following options:

  • -1: Retrieve a list of file names. The default is to retrieve a list of FileInfo objects.

  • -a: Include all files (including those starting with '.')

  • -f: Do not sort the list

  • -dirs: Include directories (they are excluded by default)

  • -links: Include symbolic links (they are excluded by default)

  • -R: List the remote directory recursively

此外，还提供了文件名筛选，其方式与 `inbound-channel-adapter`相同。请参见 FTP Inbound Channel Adapter。

In addition, filename filtering is provided, in the same manner as the inbound-channel-adapter. See FTP Inbound Channel Adapter.

ls 操作返回的消息有效负载是一个文件名列表或一个 FileInfo 对象列表。这些对象提供诸如修改时间、权限和其他详细信息之类的信息。

The message payload resulting from an ls operation is a list of file names or a list of FileInfo objects. These objects provide information such as modified time, permissions, and other details.

ls 命令操作的远程目录在 file_remoteDirectory 标头中提供。

The remote directory that the ls command acted on is provided in the file_remoteDirectory header.

当使用递归选项 (-R) 时，fileName 包含任何子目录元素，代表到该文件（相对于远程目录）的相对路径。如果包括 -dirs 选项，每个递归目录都会作为列表中的一个元素同时返回。这种情况下，建议不要使用 -1 选项，因为您将无法区分文件和目录，而使用 FileInfo 对象可以做到这一点。

When using the recursive option (-R), the fileName includes any subdirectory elements, representing a relative path to the file (relative to the remote directory). If the -dirs option is included, each recursive directory is also returned as an element in the list. In this case, it is recommended that you not use the -1 option, because you would not be able to distinguish files from directories, which you can do with the FileInfo objects.

自版本 4.3 起，FtpSession 支持 list() 和 listNames() 类型的 null。因此，您可以省略 expression 属性。为方便起见，Java 配置有两个没有 expression 参数的构造器。或者对于 LS、NLST、PUT 和 MPUT 命令，null 被视为客户端工作目录，根据 FTP 协议。所有其他命令必须提供 expression 以根据请求消息评估远程路径。当您扩展 DefaultFtpSessionFactory 并实现 postProcessClientAfterConnect() 回调时，您可以使用 FTPClient.changeWorkingDirectory() 函数设置工作目录。

Starting with version 4.3, the FtpSession supports null for the list() and listNames() methods. Therefore, you can omit the expression attribute. For convenience, Java configuration has two constructors that do not have an expression argument. or LS, NLST, PUT and MPUT commands, null is treated as the client working directory, according to the FTP protocol. All other commands must be supplied with the expression to evaluate the remote path against the request message. You can set the working directory with the FTPClient.changeWorkingDirectory() function when you extend the DefaultFtpSessionFactory and implement the postProcessClientAfterConnect() callback.

Using the nlst Command

版本 5 引入了对 nlst 命令的支持。

Version 5 introduced support for the nlst command.

nlst 列出远程文件名并仅支持一个选项：

nlst lists remote file names and supports only one option:

  • -f: Do not sort the list

nlst 操作返回的消息有效负载是一个文件名列表。

The message payload resulting from an nlst operation is a list of file names.

nlst 命令操作的远程目录在 file_remoteDirectory 标头中提供。

The remote directory that the nlst command acted on is provided in the file_remoteDirectory header.

与使用 LIST 命令的 xref:ftp/outbound-gateway.adoc#ftp-using-ls[ls 命令的 -1 选项不同，nlst 命令会向目标 FTP 服务器发送 NLST 命令。当服务器不支持 LIST（例如由于安全限制）时，此命令非常有用。nlst 操作的结果是名称，不包含其他详细信息。因此，该框架无法判断一个实体是否是一个目录，例如是为了执行筛选或递归列出。

Unlike the -1 option for the ls command, which uses the LIST command, the nlst command sends an NLST command to the target FTP server. This command is useful when the server does not support LIST (due to security restrictions, for example). The result of the nlst operation is the names without other detail. Therefore, the framework cannot determine if an entity is a directory, to perform filtering or recursive listing, for example.

Using the get Command

get 检索远程文件。它支持以下选项：

get retrieves a remote file. It supports the following option:

  • -P: Preserve the timestamp of the remote file.

  • -stream: Retrieve the remote file as a stream.

  • -D: Delete the remote file after successful transfer. The remote file is not deleted if the transfer is ignored, because the FileExistsMode is IGNORE and the local file already exists.

file_remoteDirectory 标头提供远程目录名称，file_remoteFile 标头提供文件名。

The file_remoteDirectory header provides the remote directory name, and the file_remoteFile header provides the file name.

get`操作产生的消息负载是表示检索到的文件或在您使用 `-stream`选项时的 `File`对象。-stream`选项允许将文件作为流检索。对于文本文件，一个常见的用例是将此操作与 file splitter或 stream transformer结合使用。当以流的形式消耗远程文件时，您负责在消耗流后关闭 Session。为了方便起见，`Session`在 `closeableResource`头中提供，您可以通过 `IntegrationMessageHeaderAccessor`上的便捷方法访问它。以下示例显示了如何使用便捷方法：

The message payload resulting from a get operation is a File object that represents the retrieved file or an InputStream when you use the -stream option. The -stream option allows retrieving the file as a stream. For text files, a common use case is to combine this operation with a file splitter or a stream transformer. When consuming remote files as streams, you are responsible for closing the Session after the stream is consumed. For convenience, the Session is provided in the closeableResource header, which you can access with a convenience method on IntegrationMessageHeaderAccessor The following example shows how to use the convenience method:

Closeable closeable = new IntegrationMessageHeaderAccessor(message).getCloseableResource();
if (closeable != null) {
    closeable.close();
}

file splitter和 stream transformer等框架组件在数据传输后自动关闭会话。

Framework components such as the file splitter and the stream transformer automatically close the session after the data is transferred.

以下示例显示了如何将文件作为流使用：

The following example shows how to consume a file as a stream:

<int-ftp:outbound-gateway session-factory="ftpSessionFactory"
                            request-channel="inboundGetStream"
                            command="get"
                            command-options="-stream"
                            expression="payload"
                            remote-directory="ftpTarget"
                            reply-channel="stream" />

<int-file:splitter input-channel="stream" output-channel="lines" />

如果您在自定义组件中使用输入流，您必须关闭 Session。您可以在自定义代码中执行此操作，也可以通过将消息的副本路由到 service-activator 并使用 SpEL 来执行，如下面的示例所示：

If you consume the input stream in a custom component, you must close the Session. You can do so either in your custom code or by routing a copy of the message to a service-activator and using SpEL, as the following example shows:

 
<int:service-activator input-channel="closeSession"
    expression="headers['closeableResource'].close()" />

Using the mget Command

mget 根据模式检索多个远程文件，并支持以下选项：

mget retrieves multiple remote files based on a pattern and supports the following options:

  • -P: Preserve the timestamps of the remote files.

  • -R: Retrieve the entire directory tree recursively.

  • -x: Throw an exception if no files match the pattern (otherwise an empty list is returned).

  • -D: Delete each remote file after successful transfer. The remote file is not deleted if the transfer is ignored, because the FileExistsMode is IGNORE and the local file already exists.

mget 操作产生的消息有效负载是一个 List<File> 对象（即，一个 File 对象的 List，每个文件都表示一个已检索的文件）。

The message payload resulting from an mget operation is a List<File> object (that is, a List of File objects, each representing a retrieved file).

从 5.0 版本开始，如果 FileExistsMode 是 IGNORE，输出消息的有效负载不再包含由于文件已经存在而未获取的文件。以前，该列表包含所有文件，包括已经存在的文件。

Starting with version 5.0, if the FileExistsMode is IGNORE, the payload of the output message no longer contains files that were not fetched due to the file already existing. Previously, the list contained all files, including those that already existed.

用于确定远程路径的表达式应该产生以 结尾的结果 - 例如，somedir/ 将获取 somedir 下的完整树。

The expression used to determine the remote path should produce a result that ends with - e.g. somedir/ will fetch the complete tree under somedir.

从版本 5.0 开始，递归 mget 与新的 FileExistsMode.REPLACE_IF_MODIFIED 模式结合使用，可以用于定期在本地同步整个远程目录树。无论 -P（保留时间戳）选项如何，此模式都会将本地文件的上次修改时间戳替换为远程时间戳。

Starting with version 5.0, a recursive mget, combined with the new FileExistsMode.REPLACE_IF_MODIFIED mode, can be used to periodically synchronize an entire remote directory tree locally. This mode replaces the local file’s last modified timestamp with the remote timestamp, regardless of the -P (preserve timestamp) option.

Example 1. Using recursion (-R)

将忽略模式，并假设为 *。默认检索整个远程树。但是，可以通过提供 FileListFilter 来过滤树中的文件。也可以通过这种方式过滤树中的目录。FileListFilter 可以通过引用、filename-pattern 或 filename-regex 属性提供。例如，filename-regex="(subDir|.*1.txt) 检索远程目录中所有以 1.txt 结尾的文件和 subDir 子目录。然而，下一个示例显示了一个替代方法，版本 5.0 提供了该替代方法。

The pattern is ignored, and * is assumed. By default, the entire remote tree is retrieved. However, files in the tree can be filtered, by providing a FileListFilter. Directories in the tree can also be filtered this way. A FileListFilter can be provided by reference, by filename-pattern, or by filename-regex attributes. For example, filename-regex="(subDir|.*1.txt)" retrieves all files ending with 1.txt in the remote directory and the subDir child directory. However, the next example shows an alternative, which version 5.0 made available.

如果过滤了一个子目录，则不会对该子目录执行额外的遍历。

If a subdirectory is filtered, no additional traversal of that subdirectory is performed.

不允许使用 -dirs 选项（递归 mget 使用递归 ls 来获取目录树，因此无法将目录本身包含在列表中）。

The -dirs option is not allowed (the recursive mget uses the recursive ls to obtain the directory tree, so the directories themselves cannot be included in the list).

通常，您会在 local-directory-expression 中使用 #remoteDirectory 变量，以便在本地保留远程目录结构。

Typically, you would use the #remoteDirectory variable in the local-directory-expression so that the remote directory structure is retained locally.

持久的过滤文件列表现在有一个布尔属性 forRecursion。将此属性设置为 true，还将设置 alwaysAcceptDirectories，这意味着出站网关（ls 和 mget）上的递归操作现在将始终在每次遍历完整目录树。这是为了解决目录树中深处更改未被检测到的问题。此外，forRecursion=true 会导致使用文件的完整路径作为元数据存储键；这解决了在不同目录中多次出现具有相同名称的文件时过滤器无法正常工作的问题。重要提示：这意味着无法在顶级目录下的文件找到持久元数据存储中的现有键。因此，该属性默认为 false；这可能会在未来版本中更改。

The persistent file list filters now have a boolean property forRecursion. Setting this property to true, also sets alwaysAcceptDirectories, which means that the recursive operation on the outbound gateways (ls and mget) will now always traverse the full directory tree each time. This is to solve a problem where changes deep in the directory tree were not detected. In addition, forRecursion=true causes the full path to files to be used as the metadata store keys; this solves a problem where the filter did not work properly if a file with the same name appears multiple times in different directories. IMPORTANT: This means that existing keys in a persistent metadata store will not be found for files beneath the top level directory. For this reason, the property is false by default; this may change in a future release.

从版本 5.0 开始，FtpSimplePatternFileListFilter 和 FtpRegexPatternFileListFilter 可以通过将 alwaysAcceptDirectories 属性设置为 true 来配置为始终通过目录。这样做允许对简单模式进行递归，如下面的示例所示：

Starting with version 5.0, the FtpSimplePatternFileListFilter and FtpRegexPatternFileListFilter can be configured to always pass directories by setting the alwaysAcceptDirectories property to true. Doing so allows recursion for a simple pattern, as the following examples show:

<bean id="starDotTxtFilter"
        class="org.springframework.integration.ftp.filters.FtpSimplePatternFileListFilter">
    <constructor-arg value="*.txt" />
    <property name="alwaysAcceptDirectories" value="true" />
</bean>

<bean id="dotStarDotTxtFilter"
            class="org.springframework.integration.ftp.filters.FtpRegexPatternFileListFilter">
    <constructor-arg value="^.*\.txt$" />
    <property name="alwaysAcceptDirectories" value="true" />
</bean>

定义了前一个示例中的过滤器后，您可以通过设置网关上的 filter 属性来使用一个过滤器。

Once you have defined filters such as those in the preceding example, you can use one by setting the filter property on the gateway.

另请参阅 xref:ftp/outbound-gateway.adoc#ftp-partial[Outbound Gateway Partial Success (mget 和 mput)。

See also Outbound Gateway Partial Success (mget and mput).

Using the put Command

put`命令将文件发送到远程服务器。消息的负载可以是 `java.io.File、byte[]`或 `String。remote-filename-generator（或表达式）用于给远程文件命名。其他可用的属性包括 remote-directory、temporary-remote-directory`及其 `*-expression`等效项：`use-temporary-file-name`和 `auto-create-directory。有关更多信息，请参阅 schema文档。

The put command sends a file to the remote server. The payload of the message can be a java.io.File, a byte[], or a String. A remote-filename-generator (or expression) is used to name the remote file. Other available attributes include remote-directory, temporary-remote-directory, and their *-expression equivalents: use-temporary-file-name and auto-create-directory. See the schema documentation for more information.

put 操作产生的消息有效负载是一个 String，它表示传输后服务器上文件的完整路径。

The message payload resulting from a put operation is a String that represents the full path of the file on the server after transfer.

5.2 版本引入了 chmod 属性，它可以在上传后更改远程文件权限。你可以使用传统的 Unix 八进制格式（例如，600 只允许文件所有者读写）。在使用 Java 配置适配器时，你可以使用 setChmod(0600)。仅在你 FTP 服务器支持 SITE CHMOD 子命令时适用。

Version 5.2 introduced the chmod attribute, which changes the remote file permissions after upload. You can use the conventional Unix octal format (for example, 600 allows read-write for the file owner only). When configuring the adapter using java, you can use setChmod(0600). Only applies if your FTP server supports the SITE CHMOD subcommand.

Using the mput Command

mput 将多个文件发送到服务器，只支持一个选项：

The mput sends multiple files to the server and supports only one option:

  • -R: Recursive. Send all files (possibly filtered) in the directory and its subdirectories.

消息负载必须是一个表示本地目录的 java.io.File（或 String）。自 5.1 版本起，也支持一个 File 或 String 集合。

The message payload must be a java.io.File (or String) that represents a local directory. Since version 5.1, a collection of File or String is also supported.

此命令支持与 put command相同的属性。此外，可以使用 mput-pattern、mput-regex、`mput-filter`或 `mput-filter-expression`之一过滤本地目录中的文件。只要子目录本身通过筛选器，筛选器就可以与递归一起使用。未通过筛选器的子目录不会递归。

This command supports the same attributes as the put command. In addition, files in the local directory can be filtered with one of mput-pattern, mput-regex, mput-filter, or mput-filter-expression. The filter works with recursion, as long as the subdirectories themselves pass the filter. Subdirectories that do not pass the filter are not recursed.

mput 操作产生的消息负载是一个 List<String> 对象（即，从传输结果得到的远程文件路径的 List）。

The message payload resulting from an mput operation is a List<String> object (that is, a List of remote file paths that result from the transfer).

另请参阅 xref:ftp/outbound-gateway.adoc#ftp-partial[Outbound Gateway Partial Success (mget 和 mput)。

See also Outbound Gateway Partial Success (mget and mput).

5.2 版本引入了 chmod 属性，它允许你在上传后更改远程文件权限。你可以使用传统的 Unix 八进制格式（例如，600 只允许文件所有者读写）。在使用 Java 配置适配器时，你可以使用 setChmodOctal("600") 或 setChmod(0600)。仅在你 FTP 服务器支持 SITE CHMOD 子命令时适用。

Version 5.2 introduced the chmod attribute, which lets you change the remote file permissions after upload. You can use the conventional Unix octal format (for example, 600 allows read-write for the file owner only). When configuring the adapter with Java, you can use setChmodOctal("600") or setChmod(0600). Only applies if your FTP server supports the SITE CHMOD subcommand.

Using the rm Command

rm 命令删除文件。

The rm command removes files.

rm 命令没有选项。

The rm command has no options.

如果删除成功，rm 操作产生的消息负载是 Boolean.TRUE，否则是 Boolean.FALSE。file_remoteDirectory 头提供远程目录，file_remoteFile 头提供文件名。

The message payload resulting from an rm operation is Boolean.TRUE if the remove was successful or Boolean.FALSE otherwise. The file_remoteDirectory header provides the remote directory, and the file_remoteFile header provides the file name.

Using the mv Command

mv 命令移动文件。

The mv command moves files.

mv 命令没有选项。

The mv command has no options.

expression 属性定义 “from” 路径，rename-expression 属性定义 “to” 路径。默认情况下，rename-expression 为 headers['file_renameTo']。此表达式不得计算为 null 或空 String。如有必要，将创建任何必要的远程目录。结果消息的负载是 Boolean.TRUE。file_remoteDirectory 标头提供原始远程目录，file_remoteFile 标头提供文件名。新路径在 file_renameTo 标头中。

The expression attribute defines the “from” path and the rename-expression attribute defines the “to” path. By default, the rename-expression is headers['file_renameTo']. This expression must not evaluate to null or an empty String. If necessary, any necessary remote directories are created. The payload of the result message is Boolean.TRUE. The file_remoteDirectory header provides the original remote directory, and file_remoteFile header provides the file name. The new path is in the file_renameTo header.

从 5.5.6 版本开始，remoteDirectoryExpression 可以方便地用于 mv 命令。如果“自”文件不是完整的文件路径，remoteDirectoryExpression 的结果将用作远程目录。对于“至”文件也是如此，例如，如果任务只是重命名某个目录中的远程文件。

Starting with version 5.5.6, the remoteDirectoryExpression can be used in the mv command for convenience. If the “from” file is not a full file path, the result of remoteDirectoryExpression is used as the remote directory. The same applies for the “to” file, for example, if the task is just to rename a remote file in some directory.

Additional Information about FTP Outbound Gateway Commands

get 和 mget 命令支持 local-filename-generator-expression 属性。它定义了一个 SpEL 表达式，用于在传输期间生成本地文件的名称。评估上下文的根对象是请求消息。remoteFileName 变量对于 mget 尤其有用，也可以使用——例如，local-filename-generator-expression="#remoteFileName.toUpperCase() + headers.something"。

The get and mget commands support the local-filename-generator-expression attribute. It defines a SpEL expression to generate the name of local files during the transfer. The root object of the evaluation context is the request message. The remoteFileName variable, which is particularly useful for mget, is also available — for example, local-filename-generator-expression="#remoteFileName.toUpperCase() + headers.something".

get 和 mget 命令支持 local-directory-expression 属性。它定义了一个 SpEL 表达式，用于在传输期间生成本地目录的名称。评估上下文的根对象是请求消息，但是。remoteDirectory 变量对于 mget 尤其有用，也可以使用——例如：local-directory-expression="'/tmp/local/' + #remoteDirectory.toUpperCase() + headers.something"。此属性与 local-directory 属性互斥。

The get and mget commands support the local-directory-expression attribute. It defines a SpEL expression to generate the name of local directories during the transfer. The root object of the evaluation context is the request message but. The remoteDirectory variable, which is particularly useful for mget, is also available — for example: local-directory-expression="'/tmp/local/' + #remoteDirectory.toUpperCase() + headers.something". This attribute is mutually exclusive with the local-directory attribute.

对于所有命令，网关的“expression”属性提供了命令作用的路径。对于 mget 命令，表达式可能会求值为“”，表示检索所有文件，或“somedirectory/”，等等。

For all commands, the 'expression' property of the gateway provides the path on which the command acts. For the mget command, the expression might evaluate to '', meaning to retrieve all files, or 'somedirectory/', and so on.

以下示例显示了为 ls 命令配置的网关：

The following example shows a gateway configured for an ls command:

<int-ftp:outbound-gateway id="gateway1"
    session-factory="ftpSessionFactory"
    request-channel="inbound1"
    command="ls"
    command-options="-1"
    expression="payload"
    reply-channel="toSplitter"/>

发送到 toSplitter 通道的消息的负载是 String 对象的列表，每个对象都包含一个文件名。如果省略了 command-options 属性，则它会包含 FileInfo 对象。它使用以空格分隔的选项——例如，command-options="-1 -dirs -links"。

The payload of the message sent to the toSplitter channel is a list of String objects that each contain the name of a file. If the command-options attribute was omitted, it holds FileInfo objects. It uses space-delimited options — for example, command-options="-1 -dirs -links".

从 4.2 版本开始，GET、MGET、PUT 和 MPUT 命令支持 FileExistsMode 属性（在使用命名空间支持时为 mode）。这会影响本地文件存在（GET 和 MGET）或远程文件存在（PUT 和 MPUT）时的行为。支持的模式有 REPLACE、APPEND、FAIL 和 IGNORE。为了向后兼容，PUT 和 MPUT 操作的默认模式是 REPLACE。对于 GET 和 MGET 操作，默认模式是 FAIL。

Starting with version 4.2, the GET, MGET, PUT and MPUT commands support a FileExistsMode property (mode when using the namespace support). This affects the behavior when the local file exists (GET and MGET) or the remote file exists (PUT and MPUT). Supported modes are REPLACE, APPEND, FAIL, and IGNORE. For backwards compatibility, the default mode for PUT and MPUT operations is REPLACE. For GET and MGET operations, the default is FAIL.

从版本 5.0 开始，setWorkingDirExpression()（XML 中的 working-dir-expression）选项提供在 FtpOutboundGateway（XML 中的 int-ftp:outbound-gateway）上。它允许您在运行时更改客户端工作目录。表达式针对请求消息进行评估。每次网关操作后都将还原以前的工作目录。

Starting with version 5.0, the setWorkingDirExpression() (working-dir-expression in XML) option is provided on the FtpOutboundGateway (<int-ftp:outbound-gateway> in XML). It lets you change the client working directory at runtime. The expression is evaluated against the request message. The previous working directory is restored after each gateway operation.

Configuring with Java Configuration

以下 Spring Boot 应用程序显示了如何使用 Java 配置配置出站网关的一个示例：

The following Spring Boot application shows an example of how to configure the outbound gateway with Java configuration:

@SpringBootApplication
public class FtpJavaApplication {

    public static void main(String[] args) {
        new SpringApplicationBuilder(FtpJavaApplication.class)
            .web(false)
            .run(args);
    }

    @Bean
    public SessionFactory<FTPFile> ftpSessionFactory() {
        DefaultFtpSessionFactory sf = new DefaultFtpSessionFactory();
        sf.setHost("localhost");
        sf.setPort(port);
        sf.setUsername("foo");
        sf.setPassword("foo");
        sf.setTestSession(true);
        return new CachingSessionFactory<FTPFile>(sf);
    }

    @Bean
    @ServiceActivator(inputChannel = "ftpChannel")
    public MessageHandler handler() {
        FtpOutboundGateway ftpOutboundGateway =
                          new FtpOutboundGateway(ftpSessionFactory(), "ls", "'my_remote_dir/'");
        ftpOutboundGateway.setOutputChannelName("lsReplyChannel");
        return ftpOutboundGateway;
    }

}

Configuring with the Java DSL

以下 Spring Boot 应用程序显示了一个示例，演示如何使用 Java DSL 配置出站网关：

The following Spring Boot application shows an example of how to configure the outbound gateway with the Java DSL:

@SpringBootApplication
public class FtpJavaApplication {

    public static void main(String[] args) {
        new SpringApplicationBuilder(FtpJavaApplication.class)
            .web(false)
            .run(args);
    }

    @Bean
    public SessionFactory<FTPFile> ftpSessionFactory() {
        DefaultFtpSessionFactory sf = new DefaultFtpSessionFactory();
        sf.setHost("localhost");
        sf.setPort(port);
        sf.setUsername("foo");
        sf.setPassword("foo");
        sf.setTestSession(true);
        return new CachingSessionFactory<FTPFile>(sf);
    }

    @Bean
    public FtpOutboundGatewaySpec ftpOutboundGateway() {
        return Ftp.outboundGateway(ftpSessionFactory(),
            AbstractRemoteFileOutboundGateway.Command.MGET, "payload")
            .options(AbstractRemoteFileOutboundGateway.Option.RECURSIVE)
            .regexFileNameFilter("(subFtpSource|.*1.txt)")
            .localDirectoryExpression("'localDirectory/' + #remoteDirectory")
            .localFilenameExpression("#remoteFileName.replaceFirst('ftpSource', 'localTarget')");
    }

    @Bean
    public IntegrationFlow ftpMGetFlow(AbstractRemoteFileOutboundGateway<FTPFile> ftpOutboundGateway) {
        return f -> f
            .handle(ftpOutboundGateway)
            .channel(c -> c.queue("remoteFileOutputChannel"));
    }

}

Outbound Gateway Partial Success (mget and mput)

当您对多个文件执行操作（通过使用 mget 和 mput）时，在传输了一个或多个文件后，一段时间后可能会出现异常。在这种情况下（从版本 4.2 开始），将引发 PartialSuccessException。除了通常的 MessagingException 属性（failedMessage 和 cause）外，此异常还有两个其他属性：

When you perform operations on multiple files (by using mget and mput), an exception can occur some time after one or more files have been transferred. In this case (starting with version 4.2), a PartialSuccessException is thrown. As well as the usual MessagingException properties (failedMessage and cause), this exception has two additional properties:

  • partialResults: The successful transfer results.

  • derivedInput: The list of files generated from the request message (for example, local files to transfer for an mput).

这些属性使您可以确定哪些文件已成功传输，哪些文件尚未传输。

These attributes let you determine which files were successfully transferred and which were not.

在递归 mput 的情况下，PartialSuccessException 可能具有嵌套的 PartialSuccessException 发生。

In the case of a recursive mput, the PartialSuccessException may have nested PartialSuccessException occurrences.

考虑以下目录结构：

Consider the following directory structure:

root/
|- file1.txt
|- subdir/
   | - file2.txt
   | - file3.txt
|- zoo.txt

如果异常发生在 file3.txt 上，则网关引发的 PartialSuccessException 具有 file1.txt、subdir 和 zoo.txt 的 derivedInput，以及 file1.txt 的 partialResults。其 cause 是另一个具有 file2.txt 和 file3.txt 的 derivedInput 和 file2.txt 的 partialResults 的 PartialSuccessException。

If the exception occurs on file3.txt, the PartialSuccessException thrown by the gateway has derivedInput of file1.txt, subdir, and zoo.txt and partialResults of file1.txt. Its cause is another PartialSuccessException with derivedInput of file2.txt and file3.txt and partialResults of file2.txt.