Chapter 55. Readers

Readers can read data from input files (both local and remote), receive it from the connected optional input port, read it from a dictionary, from a database, or from a JMS.

One component only generates data. Since it is also an initial node, we will describe it here.

We can distinguish Readers according to what they can read:

Generating data

A DataGenerator component generates data.

Reading flat files
  • FlatFileReader reads data from flat files (delimited or fixed length).

  • ParallelReader reads data from delimited flat files using more threads.

  • ComplexDataReader reads data from flat files whose structure is heterogeneous or mutually dependent and it uses a GUI to achieve that.

  • MultiLevelReader reads data from flat files with a heterogeneous structure.

Reading XML files
  • XMLExtract reads data from XML files using SAX technology.

  • XMLReader reads data from XML files using DOM technology.

  • XMLXPathReader reads data from XML files using XPath queries.

Generally, use XMLExtract. If you require a more complex XPath queries, use XMLReader.

Reading JSON files
  • JSONExtract reads data from JSON files using XPath queries. Based on SAX.

  • JSONReader reads data from JSON files using XPath queries. Based on DOM.

Reading other files
Reading databases
Reading JMS messages, directory structure or emails.
  • JMS messages:

    • JMSReader converts JMS messages into data records.

  • Directory structure:

    • LDAPReader converts directory structure into data records.

  • Email messages:

See also
Common Properties of Components
Specific Attribute Types
Common Properties of Readers