MockNeat is a Java 8+ library that facilitates the generation of arbitrary data for your applications.
The library is available in jcenter as a maven or gradle dependency.
For detailed information on how you can include MockNeat in your projects please check the wiki page
Any type of contributions, suggestions or new ideas are stongly appreciated. Please check this wiki page for more information.
For extensive documentation please visit the wiki.
Quick links:
- Using the library in your applications
- Creating MockNeat Objects
- The MockNeat Class;
- The MockUnit Interface
Real world examples:
Example for Generating a List of 1000 arbitrary employees that work for a fictional company called "Company.com":
// Creates a MockNeat object that internally uses
// a ThreadLocalRandom.
MockNeat m = MockNeat.threadLocal();
List<Employee> companyEmployees =
m.reflect(Employee.class) // The class we are mocking
.field("uniqueId",
m.uuids()) // Generates a random unique identifier
.field("id",
m.longSeq()) // Generates long numbers in a sequence
.field("fullName",
m.names().full()) // Generates a full name for the employer
.field("companyEmail",
m.emails().domain("company.com")) // Generates a company email with a given domain
.field("personalEmail",
m.emails()) // Generates an arbitrary email without domain constraints
.field("salaryCreditCard",
m.creditCards().types(AMERICAN_EXPRESS, MASTERCARD)) // Generate credit card numbers of 'types'
.field("external",
m.bools().probability(20.0)) // Generates Boolean values with 20% probability of obtaining True
.field("hireDate",
m.localDates().past(of(1999, 1, 1))) // Generatest a date in the past, but greater than 01.01.1987
.field("birthDate",
m.localDates().between(of(1950, 1, 1), of(1994, 1, 1))) // Generates a data in the given range
.field("pcs",
m.reflect(EmployeePC.class) // Mock an EmployeePC object
.field("uuid",
m.uuids()) // Generates an unique identifier
.field("username",
m.users()) // Generates an arbitrary username
.field("operatingSystem",
m.from(new String[]{"Linux", "Windows 10", "Windows 8"})) // Randomly selects an OS from the given List
.field("ipAddress",
m.ipv4s().type(CLASS_B)) // Generates a CLASS B IPv4 Address
.field("macAddress",
m.macs()) // Generates a MAC Address
.list(2)) // Creates a List<EmployeePC> with 2 values
.list(1000) // Creates a List<Employee> with 1000 values
.val(); // Returns the listExample for creating a CSV file with arbitrary data that has the following structure:
id, firstName, lastName, email, salary (euro)
The file should contain 1000 lines.
MockNeat m = MockNeat.threadLocal();
final Path path = Paths.get("./test.csv");
m.fmt("#{id},#{first},#{last},#{email},#{salary}")
.param("id", m.longSeq()) // Replaces #{id} with a long number in a sequence
.param("first", m.names().first()) // Replaces #{first} with a first name
.param("last", m.names().last()) // Replaces #{last} with a last name
.param("email", m.emails()) // Replaces #{email} with an arbitrary email
.param("salary", m.money().locale(GERMANY).range(2000, 5000)) // Replace #{salary} with a sum of money (EUR) in the given range
.list(1000) // Generates a list of 1000 Strings
.consume(list -> {
try { Files.write(path, list, CREATE, WRITE); }
catch (IOException e) { e.printStackTrace(); }
}); // Writes the list to a fileExample for generating numbers in intervals based on probabilities:
- Generating a number in interval [0, 100) - 20% chance;
- Generating a number in interval [100, 200) - 50% chance;
- Generating a number in interval [200, 300) - 30% chance;
Integer x = m.probabilites(Integer.class)
.add(0.2, m.ints().range(0, 100))
.add(0.5, m.ints().range(100, 200))
.add(0.3, m.ints().range(200, 300))
.val();