WPS common contracts

This project contains a set of contracts for design by contract. The contracts follow the following naming scheme:

• Methods starting with require are preconditions, which are used to check arguments
• Methods starting with check are state checks or invariants, which are used to check intermediate results for consistency
• Methods starting with ensure are postconditions, which are used to check results before returning them

The contracts

The (static) methods implementing different contracts are grouped in the following classes:

• BaseContracts to test for nullability and simple boolean conditions.
• CollectionContracts to test collections for nullability and emptiness.
• StringContracts to test strings for emptiness and blankness (and nullability).

Maven coordinates

Releases can be found in Maven central under the following coordinates:

<dependency>
    <groupId>de.wps.common</groupId>
    <artifactId>common-contracts</artifactId>
    <version>0.4</version>
</dependency>

If you do not want to get the (only) transitive dependency org.checkerframework:check-qual, you can exclude it:

<dependency>
    <groupId>de.wps.common</groupId>
    <artifactId>common-contracts</artifactId>
    <version>0.4</version>
    <exclusions>
        <exclusion>
            <groupId>org.checkerframework</groupId>
            <artifactId>checker-qual</artifactId>
        </exclusion>
    </exclusions>
</dependency>