XML File Writer Output Adapter


The TIBCO StreamBase® XML File Writer is an embedded adapter suitable for streaming tuples to a text file formatted with XML tags.

The XML file created by this adapter does not contain a root node. Each tuple streamed by the adapter should be treated as an individual document. Input fields of type list or tuple are not supported.

Each field value can be optionally parsed for XML reserved characters such as <, >, and & in field values and XML-escaped if detected. Parsing for XML escaping incurs a performance penalty; disable this feature (the default) if you are sure your input data contains no XML reserved characters.

The adapter rolls over its output file when it reaches the size specified in the (optional) Max File Size parameter. When an output file is rolled over, the current File Name is appended with the current date, formatted as: yyyyMMddhhmmss. If an output file was already created with a particular date suffix, then subsequent log files are further appended with the suffix -0, -1, -2, and so on.

The adapter flushes writes to disk after every tuple unless Flush Interval is specified. If Flush Interval is specified, then a flush() is done asynchronously. Each flush and write to the output file is synchronized to prevent partial tuples from being written to disk.


The XML File Writer adapter is configured with the properties shown in the following sections. In certain cases, properties can also be set in the StreamBase Server configuration file.

General Tab

Name: Use this required field to specify or change the name of this instance of this component, which must be unique in the current EventFlow module. The name must contain only alphabetic characters, numbers, and underscores, and no hyphens or other special characters. The first character must be alphabetic or an underscore.

Adapter: A read-only field that shows the formal name of the adapter.

Class name: Shows the fully qualified class name that implements the functionality of this adapter. If you need to reference this class name elsewhere in your application, you can right-click this field and select Copy from the context menu to place the full class name in the system clipboard.

Start options: This field provides a link to the Cluster Aware tab, where you configure the conditions under which this adapter starts.

Enable Error Output Port: Select this check box to add an Error Port to this component. In the EventFlow canvas, the Error Port shows as a red output port, always the last port for the component. See Using Error Ports to learn about Error Ports.

Description: Optionally enter text to briefly describe the component's purpose and function. In the EventFlow Editor canvas, you can see the description by pressing Ctrl while the component's tooltip is displayed.

Adapter Properties Tab

Property Description Default
File Name (string) The local file path. None
Use Default Charset (optional bool) Specifies whether the default Java platform character set should be used. If this check box is cleared, a valid character set name must be specified for the Character Set property. cleared
Character Set (optional string) The character set for the XML file you are writing.


If you specify a non-ASCII character set such as UTF-8, remember that character mappings are not necessarily one byte to one byte in non-ASCII character sets.

The setting of the system property streambase.tuple-charset. US-ASCII if the property is not set.
Truncate File (bool) If true, truncate log on startup. false, append
Max File Size (optional int) The maximum XML file size in bytes before roll; 0 = no roll. 0, unlimited
Buffer Size (optional int) The buffer size, which must be greater than 0; 0 = no buffer. 0, unlimited
Flush Interval (optional int) The frequency with which to force flush, in milliseconds; 0 = always flush. 0, write immediately
Escape (check box) If selected, characters in input tuples such as <, >, and & are XML encoded with &lt; &gt; &amp; respectively. If cleared, such characters are embedded in the resulting XML verbatim. cleared
Log Level Controls the level of verbosity the adapter uses to send notifications to the console. This setting can be higher than the containing application's log level. If set lower, the system log level will be used. Available values, in increasing order of verbosity, are: OFF, ERROR, WARN, INFO, DEBUG, TRACE. INFO

Cluster Aware Tab

Use the settings in this tab to allow this operator or adapter to start and stop based on conditions that occur at runtime in a cluster with more than one node. During initial development of the fragment that contains this operator or adapter, and for maximum compatibility with TIBCO Streaming releases before 10.5.0, leave the Cluster start policy control in its default setting, Start with module.

Cluster awareness is an advanced topic that requires an understanding of StreamBase Runtime architecture features, including clusters, quorums, availability zones, and partitions. See Cluster Awareness Tab Settings on the Using Cluster Awareness page for instructions on configuring this tab.

Concurrency Tab

Use the Concurrency tab to specify parallel regions for this instance of this component, or multiplicity options, or both. The Concurrency tab settings are described in Concurrency Options, and dispatch styles are described in Dispatch Styles.


Concurrency settings are not suitable for every application, and using these settings requires a thorough analysis of your application. For details, see Execution Order and Concurrency, which includes important guidelines for using the concurrency options.

XML Formatting

The XML file emitted from this adapter takes the following form for each input tuple:


Typechecking and Error Handling

Typechecking fails if the input tuple includes fields of type list or tuple, and if the following optional parameters are specified and do not meet the following conditions:

  • Max File Size must be greater than or equal to 0.

  • Flush Interval must be greater than or equal to 0.

  • Buffer Size must be greater than or equal to 0.

If specified and those conditions are not met, typechecking fails.

Suspend and Resume Behavior

On suspend, all tuples are written to disk and the currently open XML file is closed.

On resumption, caching is restarted. The first log message occurs at resume time + Flush Interval.