1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.maven.model.building;
20
21 import java.io.PrintWriter;
22 import java.io.StringWriter;
23 import java.util.Collections;
24 import java.util.List;
25 import org.apache.maven.model.Model;
26
27 /**
28 * Signals one ore more errors during model building. The model builder tries to collect as many problems as possible
29 * before eventually failing to provide callers with rich error information. Use {@link #getProblems()} to query the
30 * details of the failure.
31 *
32 * @author Benjamin Bentmann
33 */
34 public class ModelBuildingException extends Exception {
35
36 private final ModelBuildingResult result;
37
38 /**
39 * Creates a new exception with the specified problems.
40 *
41 * @param model The model that could not be built, may be {@code null}.
42 * @param modelId The identifier of the model that could not be built, may be {@code null}.
43 * @param problems The problems that cause this exception, may be {@code null}.
44 * @deprecated Use {@link #ModelBuildingException(ModelBuildingResult)} instead.
45 */
46 @Deprecated
47 public ModelBuildingException(Model model, String modelId, List<ModelProblem> problems) {
48 super(toMessage(modelId, problems));
49
50 if (model != null) {
51 DefaultModelBuildingResult tmp = new DefaultModelBuildingResult();
52 if (modelId == null) {
53 modelId = "";
54 }
55 tmp.addModelId(modelId);
56 tmp.setRawModel(modelId, model);
57 tmp.setProblems(problems);
58 result = tmp;
59 } else {
60 result = null;
61 }
62 }
63
64 /**
65 * Creates a new exception from the specified interim result and its associated problems.
66 *
67 * @param result The interim result, may be {@code null}.
68 */
69 public ModelBuildingException(ModelBuildingResult result) {
70 super(toMessage(result));
71 this.result = result;
72 }
73
74 /**
75 * Gets the interim result of the model building up to the point where it failed.
76 *
77 * @return The interim model building result or {@code null} if not available.
78 */
79 public ModelBuildingResult getResult() {
80 return result;
81 }
82
83 /**
84 * Gets the model that could not be built properly.
85 *
86 * @return The erroneous model or {@code null} if not available.
87 */
88 public Model getModel() {
89 if (result == null) {
90 return null;
91 }
92 if (result.getEffectiveModel() != null) {
93 return result.getEffectiveModel();
94 }
95 return result.getRawModel();
96 }
97
98 /**
99 * Gets the identifier of the POM whose effective model could not be built. The general format of the identifier is
100 * {@code <groupId>:<artifactId>:<version>} but some of these coordinates may still be unknown at the point the
101 * exception is thrown so this information is merely meant to assist the user.
102 *
103 * @return The identifier of the POM or an empty string if not known, never {@code null}.
104 */
105 public String getModelId() {
106 if (result == null || result.getModelIds().isEmpty()) {
107 return "";
108 }
109 return result.getModelIds().get(0);
110 }
111
112 /**
113 * Gets the problems that caused this exception.
114 *
115 * @return The problems that caused this exception, never {@code null}.
116 */
117 public List<ModelProblem> getProblems() {
118 if (result == null) {
119 return Collections.emptyList();
120 }
121 return Collections.unmodifiableList(result.getProblems());
122 }
123
124 private static String toMessage(ModelBuildingResult result) {
125 if (result != null && !result.getModelIds().isEmpty()) {
126 return toMessage(result.getModelIds().get(0), result.getProblems());
127 }
128 return null;
129 }
130
131 private static String toMessage(String modelId, List<ModelProblem> problems) {
132 StringWriter buffer = new StringWriter(1024);
133
134 PrintWriter writer = new PrintWriter(buffer);
135
136 writer.print(problems.size());
137 writer.print((problems.size() == 1) ? " problem was " : " problems were ");
138 writer.print("encountered while building the effective model");
139 if (modelId != null && modelId.length() > 0) {
140 writer.print(" for ");
141 writer.print(modelId);
142 }
143 writer.println();
144
145 for (ModelProblem problem : problems) {
146 writer.print("[");
147 writer.print(problem.getSeverity());
148 writer.print("] ");
149 writer.print(problem.getMessage());
150 String location = ModelProblemUtils.formatLocation(problem, modelId);
151 if (!location.isEmpty()) {
152 writer.print(" @ ");
153 writer.println(location);
154 }
155 }
156
157 return buffer.toString();
158 }
159 }