WFJL Error Handling

Go back to the WFJL Documentation Home or visit the detailed WFJL Javadoc API Reference

Overview

In addition to the standard Java exception classes, the WFJL extends the Java Exception class for Whiteflag specific errors:

• WfException: used by the org.whiteflagprotocol.java to indicate errors to other software components while processing WHiteflag data
• WfCoreException: used internally by the org.whiteflagprotocol.java.core package for incompatibilities with the Whiteflag specification
• WfCryptoException: used internally by the org.whiteflagprotocol.java.crypto package to wrap cryptographic errors
• WfUtilException: used internally by the org.whiteflagprotocol.java.util package to wrap utility errors

Software using the library should typcially only expect the WfException class to be thrown. The other error classes are primarily used internally.

Error Class Diagram

The class diagram gives a rough overview of the error classes. It is not intended as a complete or accurate reference Instead, please see the WFJL Javadoc API Reference for all details.

Detailed Implementation

Error Classes

The core package defines the WfCoreException class, that is thrown by its classes if any request is made that is not in accordance with the Whiteflag specification, e.g. when a field value is not allowed or is not correctly formatted for a specfic field.

The main package org.whiteflagprotocol.java that provides the external interface, uses the WfExcepetion class. The WfException class has a property indicating the type of error. The error types are defined by the nested enumeration WfException.ErrorType.

Error Types

The WfException.ErrorType enum defines the following error codes:

• WF_GENERIC_ERROR: generic Whiteflag error
• WF_METADATA_ERROR: incorrect or missing Whiteflag message metadata
• WF_FORMAT_ERROR: Whiteflag message format error
• WF_REFERENCE_ERROR: Whiteflag message reference error
• WF_AUTH_ERROR: Whiteflag message authentication error
• WF_SIGN_ERROR: Whiteflag signature error
• WF_CRYPTO_ERROR: Whiteflag cryptographic error

Usage

Example

An example where a Whiteflag exception is thrown during authentication of an originator:

throw new WfException("Invalid authentication data", null, WfException.ErrorType.WF_AUTH_ERROR);

Note the second argument, which is a Throwable indicating the underlying cause. It may be null if unknown or not existent.