Nontransactional Oracle File and FTP Adapters Features

Oracle JCA Adapter for FilesFTP 4-9

4.2.10 Proxy Support

The proxy support feature of the Oracle FTP Adapter can be used to transfer and retrieve data to and from the FTP servers that are located outside a firewall or can only be accessed through a proxy server. A proxy server enables the hosts in an intranet to indirectly connect to hosts on the Internet. Figure 4–3 shows how a proxy server creates connections to simulate a direct connection between the client and the remote FTP server. Figure 4–3 Remote FTP Server Communication Through a Proxy Server To use the HTTP proxy feature, your proxy server must support FTP traffic through HTTP Connection. In addition, only passive data connections are supported with this feature. For information about how to configure the Oracle FTP Adapter, see Section 4.4.5, Configuring Oracle FTP Adapter for HTTP Proxy.

4.2.11 No Payload Support

For Oracle BPEL PM and Mediator, the Oracle File and FTP Adapters provide support for publishing only file metadata such as file name, directory, file size, and last modified time to a BPEL process or Mediator and excludes the payload. The process can use this metadata for subsequent processing. For example, the process can call another reference and pass the file and directory name for further processing. So, the Oracle File and FTP Adapters can be used as a notification service to notify a process whenever a new file appears in the inbound directory. To use this feature, select the Do not read file content check box in the JDeveloper wizard while configuring the Read operation.

4.2.12 Large Payload Support

For Oracle BPEL PM and Mediator, the Oracle File Adapter provides support for transferring large files as attachments. To use this feature, select the Read File As Attachment check box in the JDeveloper wizard while configuring the Read operation. This option opaquely transfers a large amount of data from one place to another as attachments. For example, you can transfer large MS Word documents, images, and PDFs without processing their content within the composite application. For information about how to pass large payloads as attachments, see Section 4.5.6, Oracle File Adapter Read File As Attachments. Note: You must not pass large payloads as opaque schemas. Client Port 80 Port 21 Proxy Server Data Passive Port Remote FTP Server Control 4-10 Oracle Fusion Middleware Users Guide for Technology Adapters

4.2.13 File-Based Triggers

The Oracle File and FTP Adapters provide support for file-based triggers, which can be used to control inbound adapter endpoint activation. For information about how to use file-based triggers, see Section 4.3.1.4, File Polling.

4.2.14 Pre-Processing and Post-Processing of Files

The process modeler may encounter situations where files must be pre-processed before they are picked up for processing or post-processed before the files are written out to the destination folder. For example, the files that the Oracle File and FTP adapters receive may be compressed or encrypted and the adapter must decompress or decrypt the files before processing. In this case you must use a custom code to decompress or decrypt the files before processing. The Oracle File and FTP Adapters supports the use of custom code that can be plugged in for pre-processing or post-processing of files. The implementation of the pre-processing and post-processing of files is restricted to the following communication modes of the Oracle File and FTP Adapters: ■ Read File or Get File ■ Write File or Put File ■ Synchronous Read File ■ Chunked Read This section contains the following topics: ■ Section 4.2.14.1, Mechanism For Pre-Processing and Post-Processing of Files ■ Section 4.2.14.2, Configuring a Pipeline ■ Section 4.2.14.3, Using a Re-Entrant Valve For Processing Zip Files ■ Section 4.2.14.4, Configuring Batch Notification Handler

4.2.14.1 Mechanism For Pre-Processing and Post-Processing of Files

The mechanism for pre-processing and post-processing of files is configured as pipelines and valves. This section describes the concept of pipelines and valves. A pipeline consists of a series of custom-defined valves. A pipeline loads a stream from the file system, subjects the stream to processing by an ordered sequence of valves, and at the end of the processing returns the modified stream to the adapter. A valve is the primary component of execution in a processing pipeline. A valve processes the content it receives and forwards the processed content to the next valve. For example, in a scenario where the Oracle File and FTP Adapters receive files that are encrypted and zipped, you can configure a pipeline with an unzip valve followed by a decryption valve. The unzip valve extracts the file content before forwarding it to the decryption valve, which decrypts the content and the final content is made available to the Oracle File or FTP Adapter as shown in Figure 4–4 .