Java tutorial
/* * Copyright (C) 2014 Google, Inc. * * Licensed 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 auto.http.internal.codegen; import com.google.common.base.Optional; import com.squareup.javapoet.ClassName; import javax.annotation.processing.Messager; import javax.lang.model.element.Element; import static com.google.common.base.Preconditions.checkNotNull; import static javax.tools.Diagnostic.Kind.ERROR; /** * An exception thrown to indicate that a source file could not be generated. * * <p>This exception <b>should not</b> be used to report detectable, logical errors as it may mask * other errors that might have been caught upon further processing. Use a {@link ValidationReport} * for that. * * @author Gregory Kick * @since 2.0 */ final class SourceFileGenerationException extends Exception { // TODO(ronshapiro): remove these unused values private final Optional<? extends Element> associatedElement; SourceFileGenerationException(Optional<ClassName> generatedClassName, Throwable cause, Optional<? extends Element> associatedElement) { super(createMessage(generatedClassName, cause.getMessage()), cause); this.associatedElement = checkNotNull(associatedElement); } private static String createMessage(Optional<ClassName> generatedClassName, String message) { return String.format("Could not generate %s: %s.", generatedClassName.isPresent() ? generatedClassName.get() : "unknown file", message); } void printMessageTo(Messager messager) { if (associatedElement.isPresent()) { messager.printMessage(ERROR, getMessage(), associatedElement.get()); } else { messager.printMessage(ERROR, getMessage()); } } }