Java tutorial
/* * Copyright 2011 the original author or authors. * * 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 org.gradle.api.internal.tasks.execution; import com.google.common.collect.Lists; import org.gradle.api.InvalidUserDataException; import org.gradle.api.Task; import org.gradle.api.internal.TaskInternal; import org.gradle.api.internal.file.FileResolver; import org.gradle.api.internal.project.ProjectInternal; import org.gradle.api.internal.tasks.DefaultTaskValidationContext; import org.gradle.api.internal.tasks.TaskExecuter; import org.gradle.api.internal.tasks.TaskExecutionContext; import org.gradle.api.internal.tasks.TaskStateInternal; import org.gradle.api.internal.tasks.TaskValidationContext; import org.gradle.api.tasks.TaskExecutionException; import org.gradle.api.tasks.TaskValidationException; import java.util.List; /** * A {@link TaskExecuter} which performs validation before executing the task. */ public class ValidatingTaskExecuter implements TaskExecuter { private final TaskExecuter executer; public ValidatingTaskExecuter(TaskExecuter executer) { this.executer = executer; } public void execute(TaskInternal task, TaskStateInternal state, TaskExecutionContext context) { List<String> messages = Lists.newArrayList(); FileResolver resolver = ((ProjectInternal) task.getProject()).getFileResolver(); final TaskValidationContext validationContext = new DefaultTaskValidationContext(resolver, messages); try { context.getTaskProperties().validate(validationContext); } catch (Exception ex) { throw new TaskExecutionException(task, ex); } if (!messages.isEmpty()) { List<String> firstMessages = messages.subList(0, Math.min(5, messages.size())); report(task, firstMessages, state); return; } executer.execute(task, state, context); } private static void report(Task task, List<String> messages, TaskStateInternal state) { List<InvalidUserDataException> causes = Lists.newArrayListWithCapacity(messages.size()); for (String message : messages) { causes.add(new InvalidUserDataException(message)); } String errorMessage = getMainMessage(task, messages); state.setOutcome(new TaskValidationException(errorMessage, causes)); } private static String getMainMessage(Task task, List<String> messages) { if (messages.size() == 1) { return String.format("A problem was found with the configuration of %s.", task); } else { return String.format("Some problems were found with the configuration of %s.", task); } } }