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.
For extensive documentation please visit the wiki.
Quick links:
- Using the library in your applications
- Creating MockNeat Objects
- The MockNeat Class;
- The MockUnit Interface
If you want to contribute please take a look at the open issues in the Project Page.
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();