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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
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66
67
68
69 public PluginBuilder(final PluginType<?> pluginType) {
70 this.pluginType = pluginType;
71 this.clazz = pluginType.getPluginClass();
72 }
73
74
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78
79
80 public PluginBuilder withConfiguration(final Configuration configuration) {
81 this.configuration = configuration;
82 return this;
83 }
84
85
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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 return builder.build();
123 }
124 } catch (final ConfigurationException e) {
125 LOGGER.error("Could not create plugin of type {} for element {}", this.clazz, node.getName(), e);
126 return null;
127 } catch (final Exception e) {
128 LOGGER.error("Could not create plugin of type {} for element {}: {}",
129 this.clazz, node.getName(),
130 (e instanceof InvocationTargetException ? ((InvocationTargetException) e).getCause() : e).toString(), e);
131 }
132
133 try {
134 final Method factory = findFactoryMethod(this.clazz);
135 final Object[] params = generateParameters(factory);
136 return factory.invoke(null, params);
137 } catch (final Exception e) {
138 LOGGER.error("Unable to invoke factory method in {} for element {}: {}",
139 this.clazz, this.node.getName(),
140 (e instanceof InvocationTargetException ? ((InvocationTargetException) e).getCause() : e).toString(), e);
141 return null;
142 }
143 }
144
145 private void verify() {
146 Objects.requireNonNull(this.configuration, "No Configuration object was set.");
147 Objects.requireNonNull(this.node, "No Node object was set.");
148 }
149
150 private static Builder<?> createBuilder(final Class<?> clazz)
151 throws InvocationTargetException, IllegalAccessException {
152 for (final Method method : clazz.getDeclaredMethods()) {
153 if (method.isAnnotationPresent(PluginBuilderFactory.class) &&
154 Modifier.isStatic(method.getModifiers()) &&
155 TypeUtil.isAssignable(Builder.class, method.getReturnType())) {
156 ReflectionUtil.makeAccessible(method);
157 return (Builder<?>) method.invoke(null);
158 }
159 }
160 return null;
161 }
162
163 private void injectFields(final Builder<?> builder) throws IllegalAccessException {
164 final List<Field> fields = TypeUtil.getAllDeclaredFields(builder.getClass());
165 AccessibleObject.setAccessible(fields.toArray(new Field[] {}), true);
166 final StringBuilder log = new StringBuilder();
167 boolean invalid = false;
168 for (final Field field : fields) {
169 log.append(log.length() == 0 ? simpleName(builder) + "(" : ", ");
170 final Annotation[] annotations = field.getDeclaredAnnotations();
171 final String[] aliases = extractPluginAliases(annotations);
172 for (final Annotation a : annotations) {
173 if (a instanceof PluginAliases) {
174 continue;
175 }
176 final PluginVisitor<? extends Annotation> visitor =
177 PluginVisitors.findVisitor(a.annotationType());
178 if (visitor != null) {
179 final Object value = visitor.setAliases(aliases)
180 .setAnnotation(a)
181 .setConversionType(field.getType())
182 .setStrSubstitutor(configuration.getStrSubstitutor())
183 .setMember(field)
184 .visit(configuration, node, event, log);
185
186 if (value != null) {
187 field.set(builder, value);
188 }
189 }
190 }
191 final Collection<ConstraintValidator<?>> validators =
192 ConstraintValidators.findValidators(annotations);
193 final Object value = field.get(builder);
194 for (final ConstraintValidator<?> validator : validators) {
195 if (!validator.isValid(field.getName(), value)) {
196 invalid = true;
197 }
198 }
199 }
200 log.append(log.length() == 0 ? builder.getClass().getSimpleName() + "()" : ")");
201 LOGGER.debug(log.toString());
202 if (invalid) {
203 throw new ConfigurationException("Arguments given for element " + node.getName() + " are invalid");
204 }
205 checkForRemainingAttributes();
206 verifyNodeChildrenUsed();
207 }
208
209
210
211
212 private static String simpleName(final Object object) {
213 if (object == null) {
214 return "null";
215 }
216 final String cls = object.getClass().getName();
217 final int index = cls.lastIndexOf('.');
218 return index < 0 ? cls : cls.substring(index + 1);
219 }
220
221 private static Method findFactoryMethod(final Class<?> clazz) {
222 for (final Method method : clazz.getDeclaredMethods()) {
223 if (method.isAnnotationPresent(PluginFactory.class) &&
224 Modifier.isStatic(method.getModifiers())) {
225 ReflectionUtil.makeAccessible(method);
226 return method;
227 }
228 }
229 throw new IllegalStateException("No factory method found for class " + clazz.getName());
230 }
231
232 private Object[] generateParameters(final Method factory) {
233 final StringBuilder log = new StringBuilder();
234 final Class<?>[] types = factory.getParameterTypes();
235 final Annotation[][] annotations = factory.getParameterAnnotations();
236 final Object[] args = new Object[annotations.length];
237 boolean invalid = false;
238 for (int i = 0; i < annotations.length; i++) {
239 log.append(log.length() == 0 ? factory.getName() + "(" : ", ");
240 final String[] aliases = extractPluginAliases(annotations[i]);
241 for (final Annotation a : annotations[i]) {
242 if (a instanceof PluginAliases) {
243 continue;
244 }
245 final PluginVisitor<? extends Annotation> visitor = PluginVisitors.findVisitor(
246 a.annotationType());
247 if (visitor != null) {
248 final Object value = visitor.setAliases(aliases)
249 .setAnnotation(a)
250 .setConversionType(types[i])
251 .setStrSubstitutor(configuration.getStrSubstitutor())
252 .setMember(factory)
253 .visit(configuration, node, event, log);
254
255 if (value != null) {
256 args[i] = value;
257 }
258 }
259 }
260 final Collection<ConstraintValidator<?>> validators =
261 ConstraintValidators.findValidators(annotations[i]);
262 final Object value = args[i];
263 final String argName = "arg[" + i + "](" + simpleName(value) + ")";
264 for (final ConstraintValidator<?> validator : validators) {
265 if (!validator.isValid(argName, value)) {
266 invalid = true;
267 }
268 }
269 }
270 log.append(log.length() == 0 ? factory.getName() + "()" : ")");
271 checkForRemainingAttributes();
272 verifyNodeChildrenUsed();
273 LOGGER.debug(log.toString());
274 if (invalid) {
275 throw new ConfigurationException("Arguments given for element " + node.getName() + " are invalid");
276 }
277 return args;
278 }
279
280 private static String[] extractPluginAliases(final Annotation... parmTypes) {
281 String[] aliases = null;
282 for (final Annotation a : parmTypes) {
283 if (a instanceof PluginAliases) {
284 aliases = ((PluginAliases) a).value();
285 }
286 }
287 return aliases;
288 }
289
290 private void checkForRemainingAttributes() {
291 final Map<String, String> attrs = node.getAttributes();
292 if (!attrs.isEmpty()) {
293 final StringBuilder sb = new StringBuilder();
294 for (final String key : attrs.keySet()) {
295 if (sb.length() == 0) {
296 sb.append(node.getName());
297 sb.append(" contains ");
298 if (attrs.size() == 1) {
299 sb.append("an invalid element or attribute ");
300 } else {
301 sb.append("invalid attributes ");
302 }
303 } else {
304 sb.append(", ");
305 }
306 StringBuilders.appendDqValue(sb, key);
307 }
308 LOGGER.error(sb.toString());
309 }
310 }
311
312 private void verifyNodeChildrenUsed() {
313 final List<Node> children = node.getChildren();
314 if (!(pluginType.isDeferChildren() || children.isEmpty())) {
315 for (final Node child : children) {
316 final String nodeType = node.getType().getElementName();
317 final String start = nodeType.equals(node.getName()) ? node.getName() : nodeType + ' ' + node.getName();
318 LOGGER.error("{} has no parameter that matches element {}", start, child.getName());
319 }
320 }
321 }
322 }