ApplicationException

Defines a base class used to define various application exceptions.

Inherits: Exception

Description

The ApplicationException class defines a base class used to define various application exceptions.

Important points

  • Most languages have their own definition of base exception (error) types. However, this class is implemented symmetrically in all languages supported by the PipServices toolkit and allows to create portable implementations and support proper error propagation in microservices calls.
  • Error propagation means that when a microservice implemented in one language calls a microservice(s) implemented in a different language(s), errors are returned throught the entire call chain and restored in their original (or close) type.
  • Since the number of potential exception types is endless, the PipServices toolkit supports only 12 standard categories of exceptions, which are defined in ErrorCategory. The ApplicationException class acts as a basis for these 12 standard exception types.
  • Most exceptions use a free-form message that describes the occured error. However, this may not be sufficient to create meaninful error descriptions. Therefore, the ApplicationException class proposes an extended error definition that has more standard fields:
    • message: a human-readable error description
    • category: one of the 12 standard error categories
    • status: numeric HTTP status code for REST invocations
    • code: a unique error code, usually defined as “MY_ERROR_CODE”
    • correlation_id: unique transaction id used to trace execution through a call chain
    • details: map with error parameters that can help to recreate meaningful error description in other languages
    • stack_trace: stack trace
    • cause: the original error that is wrapped by this exception
  • The ApplicationException class is not serializable. To pass errors through the wire it must be converted into an ErrorDescription object and then restored on the receiving end into an identical exception type.

Constructors

Creates a new instance of application exception and assigns its values.

public ApplicationException(string category = null, string correlationId = null, string code = null, string message = null)

  • category: string - (optional) standard error category. Default: Unknown
  • correlationId: string - (optional) unique transaction id used to trace execution through the call chain.
  • code: string - (optional) unique error code. Default: “UNKNOWN”
  • message: string - (optional) human-readable description of the error.

Creates a new instance of ApplicationException.

public ApplicationException()

Creates a new instance of ApplicationException with string message.

protected ApplicationException(string message)

  • message: string - human-readable description of the error.

Creates a new instance of ApplicationException.

protected ApplicationException(SerializationInfo info, StreamingContext context)

  • info: SerializationInfo - serialization information
  • context: StreamingContext - streaming context

Properties

BaseMessage

A human-readable error description (usually written in English).

public string BaseMessage { get; set; }

Category

Standard error category.

public string Category { get; set; }

Status

HTTP status code associated with this error type.

public int Status = 500 { get; set; }

Code

A unique error code.

public string Code = ‘UNKNOWN’ { get; set; }

Details

Map with additional details that can be used to restore error descriptions in other languages.

public StringValueMap Details

CorrelationId

A unique transaction id used to trace execution throug a call chain.

public string CorrelationId { get; set; }

StackTrace

Stack trace of the exception.

public new string StackTrace { get; set; }

Cause

Original error wrapped by this exception.

public string Cause { get; set; }

Instance methods

GetObjectData

Gets information such as category, correlation_id, etc.

public override void GetObjectData(SerializationInfo info, StreamingContext context)

  • info: SerializationInfo - serialization information
  • context: StreamingContext - streaming context

WithCause

Sets a original error wrapped by this exception This method returns a reference to this exception to the implement Builder pattern to chain additional calls.

public ApplicationException WithCause(Exception cause)

WithCode

Sets a unique error code.
This method returns reference to this exception to implement the Builder pattern to chain additional calls.

public ApplicationException WithCode(string code)

WithCorrelationId

Sets a correlation id which can be used to trace this error through a call chain.
This method returns a reference to this exception to implement the Builder pattern to chain additional calls.

public ApplicationException WithCorrelationId(string correlationId)

  • correlationId: string - unique transaction id used to trace an error through the call chain
  • returns: ApplicationException - exception object

WithDetails

Sets a parameter for additional error details. This details can be used to restore error description in other languages.

This method returns a reference to this exception to implement the Builder pattern to chain additional calls.

public ApplicationException WithDetails(string key, object value)

  • key: string - key of the details parameter name
  • value: object - value of the details parameter name
  • returns: ApplicationException - exception object

WithStackTrace

Sets a stack trace for this error.
This method returns a reference to this exception to implement the Builder pattern to chain additional calls

public ApplicationException WithStackTrace(string stackTrace)

  • stackTrace: string - stack trace where this error occured
  • returns: ApplicationException - exception object

WithStatus

Sets a HTTP status code which shall be returned by REST calls. This method returns a reference to this exception to implement the Builder pattern to chain additional calls.

public ApplicationException WithStatus(int status)

Wrap

Wraps another exception into an application exception object.

If the original exception is of ApplicationException type, it is returned without changes. Otherwise, a new ApplicationException is created and the original error is set as its cause.

public ApplicationException Wrap(Exception cause)

  • cause: Exception - original error object
  • returns: ApplicationException - original or newly created ApplicationException

Static methods

WrapException

Wraps another exception into a specified application exception object.

If the original exception is of ApplicationException type, it is returned without changes. Otherwise, the original error is set as a cause for the specified ApplicationException object.

public static ApplicationException WrapException(ApplicationException error, Exception cause)

See also