Runtime Exceptions

Runtime exceptions can be thrown by the graphql engine if certain exceptional situations are encountered. The following are a list of the exceptions that can be thrown all the way out of a graphql.execute(...) call.

These are not graphql errors in execution but rather totally unacceptable conditions in which to execute a graphql query.

• graphql.schema.CoercingSerializeException

  is thrown when a value cannot be serialised by a Scalar type, for example a String value being coerced as an Int.

• graphql.schema.CoercingParseValueException

  is thrown when a value cannot be parsed by a Scalar type, for example a String input value being parsed as an Int.

• graphql.execution.UnresolvedTypeException

  is thrown if a graphql.schema.TypeResolver fails to provide a concrete object type given a interface or union type.

• graphql.execution.NonNullableValueCoercedAsNullException

  is thrown if a non null variable argument is coerced as a null value during execution.

• graphql.execution.InputMapDefinesTooManyFieldsException

  is thrown if a map used for an input type object contains more keys than is defined in that input type.

• graphql.schema.validation.InvalidSchemaException

  is thrown if the schema is not valid when built via graphql.schema.GraphQLSchema.Builder#build()

• graphql.execution.UnknownOperationException

if multiple operations are defined in the query and the operation name is missing or there is no matching operation name contained in the GraphQL query.

• graphql.GraphQLException

  is thrown as a general purpose runtime exception, for example if the code cant access a named field when examining a POJO, it is analogous to a RuntimeException if you will.

• graphql.AssertException

  is thrown as a low level code assertion exception for truly unexpected code conditions, things we assert should never happen in practice.