Add support for custom violation exceptions

scm-webapp/src/main/java/sonia/scm/api/v2/ScmConstraintValidationExceptionMapper.java

@@ -0,0 +1,30 @@
+package sonia.scm.api.v2;
+
+import sonia.scm.ScmConstraintViolationException;
+import sonia.scm.api.v2.resources.ScmViolationExceptionToErrorDtoMapper;
+
+import javax.inject.Inject;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.ext.ExceptionMapper;
+import javax.ws.rs.ext.Provider;
+
+@Provider
+public class ScmConstraintValidationExceptionMapper implements ExceptionMapper<ScmConstraintViolationException> {
+
+  private final ScmViolationExceptionToErrorDtoMapper mapper;
+
+  @Inject
+  public ScmConstraintValidationExceptionMapper(ScmViolationExceptionToErrorDtoMapper mapper) {
+    this.mapper = mapper;
+  }
+
+  @Override
+  public Response toResponse(ScmConstraintViolationException exception) {
+    return Response
+      .status(Response.Status.BAD_REQUEST)
+      .type(MediaType.APPLICATION_JSON_TYPE)
+      .entity(mapper.map(exception))
+      .build();
+  }
+}