Outra grande funcionalidade necessária pelas APIs é a validação de dados, garantindo que os dados são válidos, dados certos parâmetros. Por exemplo, que algum campo seja `int`, e não alguma string aleatória. Isso é especialmente útil para dados de entrada.

Sem um sistema de validação de dados, você teria que realizar todas as verificações manualmente, no código.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the

              <exclude>org.apache.maven.toolchain.DefaultToolchain#DefaultToolchain(org.apache.maven.toolchain.model.ToolchainModel,java.lang.String,org.codehaus.plexus.logging.Logger):CONSTRUCTOR_REMOVED</exclude>
              <exclude>org.apache.maven.toolchain.DefaultToolchainManager#logger</exclude>
              <!-- Remove plexus utils -->

 * HashCode} when finished using {@link Hasher#hash}. (See an {@linkplain #newHasher example} of
 * this.)
 *
 * <p>If all you want to hash is a single byte array, string or {@code long} value, there are
 * convenient shortcut methods defined directly on {@link HashFunction} to make this easier.
 *
 * <p>Hasher accepts primitive data types, but can also accept any Object of type {@code T} provided

 * HashCode} when finished using {@link Hasher#hash}. (See an {@linkplain #newHasher example} of
 * this.)
 *
 * <p>If all you want to hash is a single byte array, string or {@code long} value, there are
 * convenient shortcut methods defined directly on {@link HashFunction} to make this easier.
 *
 * <p>Hasher accepts primitive data types, but can also accept any Object of type {@code T} provided