001/* 002 * Copyright 2012-2018 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.boot.origin; 018 019import java.io.File; 020 021/** 022 * Interface that uniquely represents the origin of an item. For example, an item loaded 023 * from a {@link File} may have an origin made up of the file name along with line/column 024 * numbers. 025 * <p> 026 * Implementations must provide sensible {@code hashCode()}, {@code equals(...)} and 027 * {@code #toString()} implementations. 028 * 029 * @author Madhura Bhave 030 * @author Phillip Webb 031 * @since 2.0.0 032 * @see OriginProvider 033 */ 034public interface Origin { 035 036 /** 037 * Find the {@link Origin} that an object originated from. Checks if the source object 038 * is an {@link OriginProvider} and also searches exception stacks. 039 * @param source the source object or {@code null} 040 * @return an optional {@link Origin} 041 */ 042 static Origin from(Object source) { 043 if (source instanceof Origin) { 044 return (Origin) source; 045 } 046 Origin origin = null; 047 if (source != null && source instanceof OriginProvider) { 048 origin = ((OriginProvider) source).getOrigin(); 049 } 050 if (origin == null && source != null && source instanceof Throwable) { 051 return from(((Throwable) source).getCause()); 052 } 053 return origin; 054 } 055 056}