Java tutorial
package org.apache.maven.model.building; /* * 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. */ import java.io.PrintWriter; import java.io.StringWriter; import java.util.Collections; import java.util.List; import org.apache.maven.model.Model; /** * Signals one ore more errors during model building. The model builder tries to collect as many problems as possible * before eventually failing to provide callers with rich error information. Use {@link #getProblems()} to query the * details of the failure. * * @author Benjamin Bentmann */ public class ModelBuildingException extends Exception { private final ModelBuildingResult result; /** * Creates a new exception with the specified problems. * * @param model The model that could not be built, may be {@code null}. * @param modelId The identifier of the model that could not be built, may be {@code null}. * @param problems The problems that causes this exception, may be {@code null}. * @deprecated Use {@link #ModelBuildingException(ModelBuildingResult)} instead. */ @Deprecated public ModelBuildingException(Model model, String modelId, List<ModelProblem> problems) { super(toMessage(modelId, problems)); if (model != null) { DefaultModelBuildingResult tmp = new DefaultModelBuildingResult(); if (modelId == null) { modelId = ""; } tmp.addModelId(modelId); tmp.setRawModel(modelId, model); tmp.setProblems(problems); result = tmp; } else { result = null; } } /** * Creates a new exception from the specified interim result and its associated problems. * * @param result The interim result, may be {@code null}. */ public ModelBuildingException(ModelBuildingResult result) { super(toMessage(result)); this.result = result; } /** * Gets the interim result of the model building up to the point where it failed. * * @return The interim model building result or {@code null} if not available. */ public ModelBuildingResult getResult() { return result; } /** * Gets the model that could not be built properly. * * @return The erroneous model or {@code null} if not available. */ public Model getModel() { if (result == null) { return null; } if (result.getEffectiveModel() != null) { return result.getEffectiveModel(); } return result.getRawModel(); } /** * Gets the identifier of the POM whose effective model could not be built. The general format of the identifier is * {@code <groupId>:<artifactId>:<version>} but some of these coordinates may still be unknown at the point the * exception is thrown so this information is merely meant to assist the user. * * @return The identifier of the POM or an empty string if not known, never {@code null}. */ public String getModelId() { if (result == null || result.getModelIds().isEmpty()) { return ""; } return result.getModelIds().get(0); } /** * Gets the problems that caused this exception. * * @return The problems that caused this exception, never {@code null}. */ public List<ModelProblem> getProblems() { if (result == null) { return Collections.emptyList(); } return Collections.unmodifiableList(result.getProblems()); } private static String toMessage(ModelBuildingResult result) { if (result != null && !result.getModelIds().isEmpty()) { return toMessage(result.getModelIds().get(0), result.getProblems()); } return null; } private static String toMessage(String modelId, List<ModelProblem> problems) { StringWriter buffer = new StringWriter(1024); PrintWriter writer = new PrintWriter(buffer); writer.print(problems.size()); writer.print((problems.size() == 1) ? " problem was " : " problems were "); writer.print("encountered while building the effective model"); if (modelId != null && modelId.length() > 0) { writer.print(" for "); writer.print(modelId); } writer.println(); for (ModelProblem problem : problems) { writer.print("["); writer.print(problem.getSeverity()); writer.print("] "); writer.print(problem.getMessage()); writer.print(" @ "); writer.println(ModelProblemUtils.formatLocation(problem, modelId)); } return buffer.toString(); } }