Data Format Transformer

A console application designed to transform data files between JSON, XML, and CSV formats.

Capabilities

• Seamless conversion between JSON, XML, and CSV formats
• Straightforward command-line interface
• Clear and informative error reporting
• Handles tabular data structures

Prerequisites

• Java version 21+
• Maven 3.6 or above

Compilation

Execute the following command:

./mvnw clean package

This process generates an executable JAR file located at target/file-converter.jar.

Operation

Run the application using:

java -jar target/file-converter.jar --input <source-file> --output <destination-file>

Command Parameters

Parameter	Purpose	Mandatory
--input	Source file path	Yes
--output	Destination file path	Yes
--help	Display usage information	No

Sample Data Files

The examples/ directory contains demonstration files:

• examples/username.csv - Data in CSV format
• examples/username.json - Data in JSON format
• examples/username.xml - Data in XML format

Usage Demonstration

Transform CSV to JSON:

java -jar target/file-converter.jar --input examples/username.csv --output result.json

Format Specifications

JSON Format

Accepts and produces arrays of simple objects:

[
  {"id": "789", "name": "Robert", "email": "robert@company.org"},
  {"id": "456", "name": "Jennifer", "email": "jennifer@company.org"}
]

Individual objects are also valid:

{"id": "789", "name": "Robert", "email": "robert@company.org"}

XML Format

<?xml version="1.0" encoding="UTF-8"?>
<records>
  <record>
    <id>789</id>
    <name>Robert</name>
    <email>robert@company.org</email>
  </record>
  <record>
    <id>456</id>
    <name>Jennifer</name>
    <email>jennifer@company.org</email>
  </record>
</records>

CSV Format

id,name,email
789,Robert,robert@company.org
456,Jennifer,jennifer@company.org

Technical Constraints

• Text-based values: All data elements are handled as text strings during format conversion.
• Tabular data only: Complex nested objects and arrays are not processed. The tool will indicate an error when such structures are encountered.

Error Handling

Condition	Response Message
File unavailable	Error: Input file 'path' could not be located
Malformed XML	Error: XML parsing failed: message
Unsupported extension	Error: File format '.xyz' is not supported
Malformed JSON	Error: JSON syntax error detected at line X
Complex data structure	Error: Complex nested structures cannot be processed. Use flat data
Missing input parameter	Error: Required --input argument not provided
Missing output parameter	Error: Required --output argument not provided

Test Execution

Run the test suite with:

./mvnw test