DataGenCLI - Data Generator CLI

A CLI (Command Line Interface) utility for generating data, based on Java Faker library - https://github.com/DiUS/java-faker

License: MIT

Last release: https://github.com/apreto/datagencli/releases/latest

Binary/Executable: https://github.com/apreto/datagencli/releases/download/v0.2/datagencli-0.2.jar (executable jar file, ready to use, built from last release)

Building

• mvn clean install

Resulting (executable) jar file will be on target/datagencli-0.2-jar-with-dependencies.jar

Usage

• List available fields (from Java Faker API)
  • java -jar datagencli.jar --listfields
• Generate Data
  • java -jar datagencli.jar --rows=100 --fields='name.fullName,date.birthday'
  • java -jar datagencli.jar --mbs=10 --separator=, --fields='randomLong(1:10000),lorem.sentence'

Generated lines (rows) are written to stdout. Error messages, usage options or fields (with --listfields) option are written to stderr.

Available command line options

• --listfields : list all available fields from Java Faker API
• --fields=fields-list : comma separated list of fields to generate (see available fields with --listfields)
• --rows=number-of-rows : number of rows (lines) to generate. Cannot be used in conjunction with --mbs.
• --mbs=number-of-megabytes : (approximate) number of Megabytes of data to generate. Cannot be used in conjunction with --rows
• --separator=separator-string : char/string separating each field in each generated row/line
• --header=fields-name-list : comma separated list of column names, written as header to output before generating rows. Option --headerline takes precedence over this
• --headerline=header-line : header line to add to output, before generating rows. This option takes precedence over --header
• --sleep=num-of-milisecs : sleeps N miliseconds after generating each row, on each thread. To control number of threads run java with java -Djava.util.concurrent.ForkJoinPool.common.parallelism=0 -jar datagencli.jar ...
• --out=myfile.csv : writes output to specified file instead of console

Examples

Example 1:

java -jar datagencli.jar --mbs=10 --separator=; --fields=internet.uuid,name.fullName,date.birthDate,address.fullAddress --header='id,name,birthDate,address' > customers.csv

Generates 10Mb of CSV data with ';' as separator, add a header with column names for each field (id, name, birthDate, address).

Example 2:

java -jar datagencli.jar --rows=1000 --separator=, --fields='internet.uuid,commerce.productName,randomLong(10:1000),randomDouble(2:150:700),randomString(AA###??ZR)' --header='productId,name,itemsInStock,price,promotionCode' --out=products.csv

Generates 1000 rows of CSV data with header and fields id, productName, itemsInStock (random number between 10 and 1000), price (random double between 150 and 700 and 2 decimal places) and promotionCode (string starting with AA, 3 digits, 2 letters and ending with ZR), writes them to file products.csv

Example 3:

java -jar datagencli.jar --rows=5 --fields=superhero.name

Generate 5 random superhero names (you never know when you will need it)

Example 4:

java -Djava.util.concurrent.ForkJoinPool.common.parallelism=0 -jar datagencli.jar --fields=yoda.quote --rows=1000 --sleep=5000

Generates a Master Yoda quote every 5 seconds (up to 1000 quotes) and writes to console. Useful for using unix pipes to send this to other command (e.g., kafka-console-producer.sh).