tFileOutputPositional - 6.3

Talend Open Studio for Big Data Components Reference Guide

EnrichVersion
6.3
EnrichProdName
Talend Open Studio for Big Data
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Function

tFileOutputPositional writes a file row by row according to the length and the format of the fields or columns in a row.

Purpose

It writes a file row by row, according to the data structure (schema) coming from the input flow.

tFileOutputPositional Properties

Component Family

File/Output

 

Basic settings

Property type

Either Built-In or Repository.

 

 

Built-In: No property data stored centrally.

 

 

Repository: Select the repository file where the properties are stored.

 

Use Output Stream

Select this check box process the data flow of interest. Once you have selected it, the Output Stream field displays and you can type in the data flow of interest.

The data flow to be processed must be added to the flow in order for this component to fetch these data via the corresponding representative variable.

This variable could be already pre-defined in your Studio or provided by the context or the components you are using along with this component; otherwise, you could define it manually and use it according to the design of your Job, for example, using tJava or tJavaFlex.

In order to avoid the inconvenience of hand writing, you could select the variable of interest from the auto-completion list (Ctrl+Space) to fill the current field on condition that this variable has been properly defined.

For further information about how to use a stream, see Scenario 2: Reading data from a remote file in streaming mode.

 

File Name

Name or path to the file to be processed and or the variable to be used.

This field becomes unavailable once you have selected the Use Output Stream check box.

For further information about how to define and use a variable in a Job, see Talend Studio User Guide.

 

Schema and Edit Schema

A schema is a row description. It defines the number of fields (columns) to be processed and passed on to the next component. The schema is either Built-In or stored remotely in the Repository.

Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

  • View schema: choose this option to view the schema only.

  • Change to built-in property: choose this option to change the schema to Built-in for local changes.

  • Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the [Repository Content] window.

 

 

Built-In: You create and store the schema locally for this component only. Related topic: see Talend Studio User Guide.

 

 

Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs. Related topic: see Talend Studio User Guide.

 

Row separator

Enter the separator used to identify the end of a row.

 

Append

Select this check box to add the new rows at the end of the file.

 

Include header

Select this check box to include the column header to the file.

 

Compress as zip file

Select this check box to compress the output file in zip format.

 

Formats

Customize the positional file data format and fill in the columns in the Formats table.

Column: Select the column you want to customize.

Size: Enter the column size.

Padding char: Type in between quotes the padding characters used. A space by default.

Alignment: Select the appropriate alignment parameter.

Keep: If the data in the column or in the field are too long, select the part you want to keep.

Advanced settings

Advanced separator (for numbers)

Select this check box to change the separator used for numbers. By default, the thousands separator is a comma (,) and the decimal separator is a period (.).

Thousands separator: define separators for thousands.

Decimal separator: define separators for decimals.

 

Use byte length as the cardinality

Select this check box to add support of double-byte character to this component. JDK 1.6 is required for this feature.

 

Create directory if not exists

This check box is selected by default. It creates a directory to hold the output table if it does not exist.

 

Custom the flush buffer size

Select this check box to define the number of lines to write before emptying the buffer.

Row Number: set the number of lines to write.

 

Output in row mode

Writes in row mode.

 

Encoding

Select the encoding from the list or select Custom and define it manually. This field is compulsory for database data handling.

 

Don't generate empty file

Select this check box if you do not want to generate empty files.

 

tStatCatcher Statistics

Select this check box to gather the Job processing metadata at a Job level as well as at each component level.

Dynamic settings

Click the [+] button to add a row in the table and fill the Code field with a context variable to choose your HDFS connection dynamically from multiple connections planned in your Job. This feature is useful when you need to access files in different HDFS systems or different distributions, especially when you are working in an environment where you cannot change your Job settings, for example, when your Job has to be deployed and executed independent of Talend Studio.

The Dynamic settings table is available only when the Use an existing connection check box is selected in the Basic settings view. Once a dynamic parameter is defined, the Component List box in the Basic settings view becomes unusable.

For examples on using dynamic parameters, see Scenario 3: Reading data from MySQL databases through context-based dynamic connections and Scenario: Reading data from different MySQL databases using dynamically loaded connection parameters. For more information on Dynamic settings and context variables, see Talend Studio User Guide.

Global Variables

NB_LINE: the number of rows read by an input component or transferred to an output component. This is an After variable and it returns an integer.

ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl + Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio User Guide.

Usage

Use this component to read a file and separate the fields using the specified separator.

Log4j

If you are using a subscription-based version of the Studio, the activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Related scenario

For a related scenario, see Scenario: Regex to Positional file.

For scenario about the usage of Use Output Stream check box, see Scenario 2: Utilizing Output Stream to save filtered data to a local file.