1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18 package org.apache.logging.log4j.core.config.plugins.util;
19
20 import java.lang.annotation.Annotation;
21 import java.lang.reflect.AccessibleObject;
22 import java.lang.reflect.Field;
23 import java.lang.reflect.InvocationTargetException;
24 import java.lang.reflect.Method;
25 import java.lang.reflect.Modifier;
26 import java.util.Collection;
27 import java.util.List;
28 import java.util.Map;
29 import java.util.Objects;
30
31 import org.apache.logging.log4j.Logger;
32 import org.apache.logging.log4j.core.LogEvent;
33 import org.apache.logging.log4j.core.config.Configuration;
34 import org.apache.logging.log4j.core.config.ConfigurationException;
35 import org.apache.logging.log4j.core.config.Node;
36 import org.apache.logging.log4j.core.config.plugins.PluginAliases;
37 import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
38 import org.apache.logging.log4j.core.config.plugins.PluginFactory;
39 import org.apache.logging.log4j.core.config.plugins.validation.ConstraintValidator;
40 import org.apache.logging.log4j.core.config.plugins.validation.ConstraintValidators;
41 import org.apache.logging.log4j.core.config.plugins.visitors.PluginVisitor;
42 import org.apache.logging.log4j.core.config.plugins.visitors.PluginVisitors;
43 import org.apache.logging.log4j.core.util.Builder;
44 import org.apache.logging.log4j.core.util.ReflectionUtil;
45 import org.apache.logging.log4j.core.util.TypeUtil;
46 import org.apache.logging.log4j.status.StatusLogger;
47 import org.apache.logging.log4j.util.StringBuilders;
48
49
50
51
52
53 public class PluginBuilder implements Builder<Object> {
54
55 private static final Logger LOGGER = StatusLogger.getLogger();
56
57 private final PluginType<?> pluginType;
58 private final Class<?> clazz;
59
60 private Configuration configuration;
61 private Node node;
62 private LogEvent event;
63
64
65
66
67
68
69 public PluginBuilder(final PluginType<?> pluginType) {
70 this.pluginType = pluginType;
71 this.clazz = pluginType.getPluginClass();
72 }
73
74
75
76
77
78
79
80 public PluginBuilder withConfiguration(final Configuration configuration) {
81 this.configuration = configuration;
82 return this;
83 }
84
85
86
87
88
89
90
91 public PluginBuilder withConfigurationNode(final Node node) {
92 this.node = node;
93 return this;
94 }
95
96
97
98
99
100
101
102 public PluginBuilder forLogEvent(final LogEvent event) {
103 this.event = event;
104 return this;
105 }
106
107
108
109
110
111
112 @Override
113 public Object build() {
114 verify();
115
116 try {
117 LOGGER.debug("Building Plugin[name={}, class={}].", pluginType.getElementName(),
118 pluginType.getPluginClass().getName());
119 final Builder<?> builder = createBuilder(this.clazz);
120 if (builder != null) {
121 injectFields(builder);
122 final Object result = builder.build();
123 return result;
124 }
125 } catch (final Exception e) {
126 LOGGER.error("Unable to inject fields into builder class for plugin type {}, element {}.", this.clazz,
127 node.getName(), e);
128 }
129
130 try {
131 final Method factory = findFactoryMethod(this.clazz);
132 final Object[] params = generateParameters(factory);
133 final Object plugin = factory.invoke(null, params);
134 return plugin;
135 } catch (final Exception e) {
136 LOGGER.error("Unable to invoke factory method in class {} for element {}.", this.clazz, this.node.getName(),
137 e);
138 return null;
139 }
140 }
141
142 private void verify() {
143 Objects.requireNonNull(this.configuration, "No Configuration object was set.");
144 Objects.requireNonNull(this.node, "No Node object was set.");
145 }
146
147 private static Builder<?> createBuilder(final Class<?> clazz)
148 throws InvocationTargetException, IllegalAccessException {
149 for (final Method method : clazz.getDeclaredMethods()) {
150 if (method.isAnnotationPresent(PluginBuilderFactory.class) &&
151 Modifier.isStatic(method.getModifiers()) &&
152 TypeUtil.isAssignable(Builder.class, method.getGenericReturnType())) {
153 ReflectionUtil.makeAccessible(method);
154 final Builder<?> builder = (Builder<?>) method.invoke(null);
155 return builder;
156 }
157 }
158 return null;
159 }
160
161 private void injectFields(final Builder<?> builder) throws IllegalAccessException {
162 final Field[] fields = builder.getClass().getDeclaredFields();
163 AccessibleObject.setAccessible(fields, true);
164 final StringBuilder log = new StringBuilder();
165 boolean invalid = false;
166 for (final Field field : fields) {
167 log.append(log.length() == 0 ? simpleName(builder) + "(" : ", ");
168 final Annotation[] annotations = field.getDeclaredAnnotations();
169 final String[] aliases = extractPluginAliases(annotations);
170 for (final Annotation a : annotations) {
171 if (a instanceof PluginAliases) {
172 continue;
173 }
174 final PluginVisitor<? extends Annotation> visitor =
175 PluginVisitors.findVisitor(a.annotationType());
176 if (visitor != null) {
177 final Object value = visitor.setAliases(aliases)
178 .setAnnotation(a)
179 .setConversionType(field.getType())
180 .setStrSubstitutor(configuration.getStrSubstitutor())
181 .setMember(field)
182 .visit(configuration, node, event, log);
183
184 if (value != null) {
185 field.set(builder, value);
186 }
187 }
188 }
189 final Collection<ConstraintValidator<?>> validators =
190 ConstraintValidators.findValidators(annotations);
191 final Object value = field.get(builder);
192 for (final ConstraintValidator<?> validator : validators) {
193 if (!validator.isValid(field.getName(), value)) {
194 invalid = true;
195 }
196 }
197 }
198 log.append(log.length() == 0 ? builder.getClass().getSimpleName() + "()" : ")");
199 LOGGER.debug(log.toString());
200 if (invalid) {
201 throw new ConfigurationException("Arguments given for element " + node.getName() + " are invalid");
202 }
203 checkForRemainingAttributes();
204 verifyNodeChildrenUsed();
205 }
206
207
208
209
210 private String simpleName(final Object object) {
211 if (object == null) {
212 return "null";
213 }
214 final String cls = object.getClass().getName();
215 final int index = cls.lastIndexOf('.');
216 return index < 0 ? cls : cls.substring(index + 1);
217 }
218
219 private static Method findFactoryMethod(final Class<?> clazz) {
220 for (final Method method : clazz.getDeclaredMethods()) {
221 if (method.isAnnotationPresent(PluginFactory.class) &&
222 Modifier.isStatic(method.getModifiers())) {
223 ReflectionUtil.makeAccessible(method);
224 return method;
225 }
226 }
227 throw new IllegalStateException("No factory method found for class " + clazz.getName());
228 }
229
230 private Object[] generateParameters(final Method factory) {
231 final StringBuilder log = new StringBuilder();
232 final Class<?>[] types = factory.getParameterTypes();
233 final Annotation[][] annotations = factory.getParameterAnnotations();
234 final Object[] args = new Object[annotations.length];
235 boolean invalid = false;
236 for (int i = 0; i < annotations.length; i++) {
237 log.append(log.length() == 0 ? factory.getName() + "(" : ", ");
238 final String[] aliases = extractPluginAliases(annotations[i]);
239 for (final Annotation a : annotations[i]) {
240 if (a instanceof PluginAliases) {
241 continue;
242 }
243 final PluginVisitor<? extends Annotation> visitor = PluginVisitors.findVisitor(
244 a.annotationType());
245 if (visitor != null) {
246 final Object value = visitor.setAliases(aliases)
247 .setAnnotation(a)
248 .setConversionType(types[i])
249 .setStrSubstitutor(configuration.getStrSubstitutor())
250 .setMember(factory)
251 .visit(configuration, node, event, log);
252
253 if (value != null) {
254 args[i] = value;
255 }
256 }
257 }
258 final Collection<ConstraintValidator<?>> validators =
259 ConstraintValidators.findValidators(annotations[i]);
260 final Object value = args[i];
261 final String argName = "arg[" + i + "](" + simpleName(value) + ")";
262 for (final ConstraintValidator<?> validator : validators) {
263 if (!validator.isValid(argName, value)) {
264 invalid = true;
265 }
266 }
267 }
268 log.append(log.length() == 0 ? factory.getName() + "()" : ")");
269 checkForRemainingAttributes();
270 verifyNodeChildrenUsed();
271 LOGGER.debug(log.toString());
272 if (invalid) {
273 throw new ConfigurationException("Arguments given for element " + node.getName() + " are invalid");
274 }
275 return args;
276 }
277
278 private static String[] extractPluginAliases(final Annotation... parmTypes) {
279 String[] aliases = null;
280 for (final Annotation a : parmTypes) {
281 if (a instanceof PluginAliases) {
282 aliases = ((PluginAliases) a).value();
283 }
284 }
285 return aliases;
286 }
287
288 private void checkForRemainingAttributes() {
289 final Map<String, String> attrs = node.getAttributes();
290 if (!attrs.isEmpty()) {
291 final StringBuilder sb = new StringBuilder();
292 for (final String key : attrs.keySet()) {
293 if (sb.length() == 0) {
294 sb.append(node.getName());
295 sb.append(" contains ");
296 if (attrs.size() == 1) {
297 sb.append("an invalid element or attribute ");
298 } else {
299 sb.append("invalid attributes ");
300 }
301 } else {
302 sb.append(", ");
303 }
304 StringBuilders.appendDqValue(sb, key);
305 }
306 LOGGER.error(sb.toString());
307 }
308 }
309
310 private void verifyNodeChildrenUsed() {
311 final List<Node> children = node.getChildren();
312 if (!(pluginType.isDeferChildren() || children.isEmpty())) {
313 for (final Node child : children) {
314 final String nodeType = node.getType().getElementName();
315 final String start = nodeType.equals(node.getName()) ? node.getName() : nodeType + ' ' + node.getName();
316 LOGGER.error("{} has no parameter that matches element {}", start, child.getName());
317 }
318 }
319 }
320 }