Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.lang3.exception; import java.util.List; import java.util.Set; import org.apache.commons.lang3.tuple.Pair; /** * Allows the storage and retrieval of contextual information based on label-value * pairs for exceptions. * <p> * Implementations are expected to manage the pairs in a list-style collection * that keeps the pairs in the sequence of their addition. * </p> * * @see ContextedException * @see ContextedRuntimeException * @since 3.0 */ public interface ExceptionContext { /** * Adds a contextual label-value pair into this context. * <p> * The pair will be added to the context, independently of an already * existing pair with the same label. * </p> * * @param label the label of the item to add, {@code null} not recommended * @param value the value of item to add, may be {@code null} * @return {@code this}, for method chaining, not {@code null} */ ExceptionContext addContextValue(String label, Object value); /** * Sets a contextual label-value pair into this context. * <p> * The pair will be added normally, but any existing label-value pair with * the same label is removed from the context. * </p> * * @param label the label of the item to add, {@code null} not recommended * @param value the value of item to add, may be {@code null} * @return {@code this}, for method chaining, not {@code null} */ ExceptionContext setContextValue(String label, Object value); /** * Retrieves all the contextual data values associated with the label. * * @param label the label to get the contextual values for, may be {@code null} * @return the contextual values associated with the label, never {@code null} */ List<Object> getContextValues(String label); /** * Retrieves the first available contextual data value associated with the label. * * @param label the label to get the contextual value for, may be {@code null} * @return the first contextual value associated with the label, may be {@code null} */ Object getFirstContextValue(String label); /** * Retrieves the full set of labels defined in the contextual data. * * @return the set of labels, not {@code null} */ Set<String> getContextLabels(); /** * Retrieves the full list of label-value pairs defined in the contextual data. * * @return the list of pairs, not {@code null} */ List<Pair<String, Object>> getContextEntries(); /** * Gets the contextualized error message based on a base message. * This will add the context label-value pairs to the message. * * @param baseMessage the base exception message <b>without</b> context information appended * @return the exception message <b>with</b> context information appended, not {@code null} */ String getFormattedExceptionMessage(String baseMessage); }