Chapter 55. Readers

Common Properties of 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

CloverDataReader reads data from files in CloverDX binary format.
SpreadsheetDataReader reads data from XLS or XLSX files.
DBFDataReader reads data from dBase files.
HadoopReader reads data from Hadoop sequence files.

Reading databases

DBInputTable unloads data from database using a JDBC driver.
QuickBaseRecordWriter reads data from a QuickBase online database.
QuickBaseImportCSV reads data from a QuickBase online database using queries.
LotusReader reads data from a Lotus Notes or Lotus Domino database.
MongoDBReader reads data from a MongoDB NoSQL database.
SalesforceBulkReader reads data from a Salesforce cloud platform using Bulk API.
SalesforceReader reads data from a Salesforce cloud platform using SOAP API.

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:
- EmailReader Reads email messages.