feat: Add generic ApplicationException

feat: Mark AuthHelper as deprecated

fix: Fix NullPointerMapper to catch NPEs

Resolves #65 (closed)

core/src/main/java/org/eclipsefoundation/core/exception/ApplicationException.java

+/*********************************************************************
+* Copyright (c) 2023 Eclipse Foundation.
+*
+* This program and the accompanying materials are made
+* available under the terms of the Eclipse Public License 2.0
+* which is available at https://www.eclipse.org/legal/epl-2.0/
+*
+* Author: Zachary Sabourin <zachary.sabourin@eclipse-foundation.org>
+*
+* SPDX-License-Identifier: EPL-2.0
+**********************************************************************/
+package org.eclipsefoundation.core.exception;
+
+/**
+ * A custom exception used as a wrapper to handle basic runtime exceptions.
+ */
+public class ApplicationException extends RuntimeException {
+
+    private final Integer statusCode;
+
+    /**
+     * Instantiate an ApplicationException with a message. 500 Status is assumed.
+     * 
+     * @param message the message to display
+     */
+    public ApplicationException(String message) {
+        this(message, 500);
+    }
+
+    /**
+     * Instantiate an ApplicationException with a message and http response status
+     * code.
+     * 
+     * @param message    the message to display
+     * @param statusCode The status code to return to the client
+     */
+    public ApplicationException(String message, Integer statusCode) {
+        super(message);
+        this.statusCode = statusCode;
+    }
+
+    /**
+     * Instantiate an ApplicationException with a message and a cause. Status 500 is
+     * assumed.
+     * 
+     * @param message the message to display
+     * @param cause   The cause of the error
+     */
+    public ApplicationException(String message, Throwable cause) {
+        this(message, cause, 500);
+    }
+
+    /**
+     * Instantiate an ApplicationException with a message, http response code, and a
+     * cause;
+     * 
+     * @param message    the message to display
+     * @param cause      The cause of the error
+     * @param statusCode The status code to return to the client
+     */
+    public ApplicationException(String message, Throwable cause, Integer statusCode) {
+        super(message, cause);
+        this.statusCode = statusCode;
+    }
+
+    /**
+     * Retrieve the current status code.
+     * 
+     * @return The exception status code.
+     */
+    public Integer getStatusCode() {
+        return this.statusCode;
+    }
+}

[Martin Lowe]

We're going to want to enable the ability to pass status codes here, so that we can have a little bit of control over code. Just in case

[Zachary Sabourin]

I've updated the constructors to support custom status codes :)