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Dummy4j

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Find method (since 0.10.0)

If you need a particular method but aren’t sure where to find it, you can use the find(...) method to quickly locate it:

String message = dummy4j.find("name");

The above code will return a message like this, listing all methods containing the given search string:

[...]
Dummy4j.color().name()
Dummy4j.color().primaryName()
Dummy4j.finance().creditCard().getOwnerName()
[...]
Dummy4j.finance().currencyName()
Dummy4j.internet().username()
Dummy4j.name()
Dummy4j.name().firstName()
[...]

Chance method (since 0.5.0)

You might want to randomize which fields should be filled and which should be left empty in an object. You can do this using the chance(...) method:

String thisValueMightBeNull = dummy4j.chance(1, 3, () -> "hello");

In the above code, there is a one-in-three chance that the value will contain "hello" and a two-in-three chance that it will be null.

Random element from an array, collection or array of suppliers (since 0.5.0)

The of(...) methods return a random element from a given array, collection or an array of suppliers.

String elementFromArray = dummy.oneOf(new String[]{ "one", "two", "three" });

String elementFromCollection = dummy.oneOf(Arrays.asList("one", "two", "three"));

String nameOrCity = dummy.oneOf(() -> dummy.name().fullName(), () -> dummy.address().city());

Globally unique values (experimental) (since 0.1.2)

It is possible to generate globally unique values by wrapping a call with the dummy.unique().value(...) method:

for (int i = 0; i < 10; i++) {
    System.out.println(
      dummy.unique().value("fullNameGroup", () -> dummy.name().fullName())
    );
}

The above will print 10 names, all of which will be unique within the fullNameGroup uniqueness group. The uniqueness is guaranteed for the entire lifetime of a Dummy4j instance.

Note that this is an experimental feature and its API may be subject to change.

Collections of locally unique values (experimental) (since 0.7.0)

It is possible to generate collections of locally unique values by wrapping a call with the dummy.unique().of(...) method:

List<String> tenUniqueNames = dummy.unique().of(() -> dummy.name().fullName(), name -> dummy.listOf(10, name));
System.out.println(tenUniqueNames);

The above will print 10 names, all of which will be unique within the list.

Note that this is an experimental feature and its API may be subject to change.

Locally unique values within a code block (experimental) (since 0.7.0)

It is possible to generate locally unique values by wrapping a code block with the dummy.unique().within(...) method:

dummy.unique().within(() -> dummy.name().fullName(), name -> {
    for (int i = 0; i < 10; i++) {
        System.out.println(name.get());
    }
});

The above will print 10 names, all of which will be unique within the wrapped consumer code block.

Note that this is an experimental feature and its API may be subject to change.

Generating collections (since 0.4.0)

Dummy4j provides convenience methods to quickly create collections of items.

List<String> fiveNames = dummy.listOf(5, () -> dummy.name().fullName());
Set<String> fourCities = dummy.setOf(4, () -> dummy.address().city());

Random Enum values (since 0.5.0)

You can generate a random enum value by providing an enum class.

MyEnum randomEnum = dummy.nextEnum(MyEnum.class);