001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.logging.log4j.core.config.plugins.util; 019 020import java.lang.annotation.Annotation; 021import java.lang.reflect.AccessibleObject; 022import java.lang.reflect.Field; 023import java.lang.reflect.InvocationTargetException; 024import java.lang.reflect.Method; 025import java.lang.reflect.Modifier; 026import java.util.Collection; 027import java.util.List; 028import java.util.Map; 029 030import org.apache.logging.log4j.Logger; 031import org.apache.logging.log4j.core.LogEvent; 032import org.apache.logging.log4j.core.config.Configuration; 033import org.apache.logging.log4j.core.config.ConfigurationException; 034import org.apache.logging.log4j.core.config.Node; 035import org.apache.logging.log4j.core.config.plugins.PluginAliases; 036import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory; 037import org.apache.logging.log4j.core.config.plugins.PluginFactory; 038import org.apache.logging.log4j.core.config.plugins.validation.ConstraintValidator; 039import org.apache.logging.log4j.core.config.plugins.validation.ConstraintValidators; 040import org.apache.logging.log4j.core.config.plugins.visitors.PluginVisitor; 041import org.apache.logging.log4j.core.config.plugins.visitors.PluginVisitors; 042import org.apache.logging.log4j.core.lookup.ConfigurationStrSubstitutor; 043import org.apache.logging.log4j.core.util.Assert; 044import org.apache.logging.log4j.core.util.Builder; 045import org.apache.logging.log4j.core.util.ReflectionUtil; 046import org.apache.logging.log4j.core.util.TypeUtil; 047import org.apache.logging.log4j.status.StatusLogger; 048import org.apache.logging.log4j.util.StringBuilders; 049 050/** 051 * Builder class to instantiate and configure a Plugin object using a PluginFactory method or PluginBuilderFactory 052 * builder class. 053 */ 054public class PluginBuilder implements Builder<Object> { 055 056 private static final Logger LOGGER = StatusLogger.getLogger(); 057 058 private final PluginType<?> pluginType; 059 private final Class<?> clazz; 060 061 private Configuration configuration; 062 private Node node; 063 private LogEvent event; 064 065 /** 066 * Constructs a PluginBuilder for a given PluginType. 067 * 068 * @param pluginType type of plugin to configure 069 */ 070 public PluginBuilder(final PluginType<?> pluginType) { 071 this.pluginType = pluginType; 072 this.clazz = pluginType.getPluginClass(); 073 } 074 075 /** 076 * Specifies the Configuration to use for constructing the plugin instance. 077 * 078 * @param configuration the configuration to use. 079 * @return {@code this} 080 */ 081 public PluginBuilder withConfiguration(final Configuration configuration) { 082 this.configuration = configuration; 083 return this; 084 } 085 086 /** 087 * Specifies the Node corresponding to the plugin object that will be created. 088 * 089 * @param node the plugin configuration node to use. 090 * @return {@code this} 091 */ 092 public PluginBuilder withConfigurationNode(final Node node) { 093 this.node = node; 094 return this; 095 } 096 097 /** 098 * Specifies the LogEvent that may be used to provide extra context for string substitutions. 099 * 100 * @param event the event to use for extra information. 101 * @return {@code this} 102 */ 103 public PluginBuilder forLogEvent(final LogEvent event) { 104 this.event = event; 105 return this; 106 } 107 108 /** 109 * Builds the plugin object. 110 * 111 * @return the plugin object or {@code null} if there was a problem creating it. 112 */ 113 @Override 114 public Object build() { 115 verify(); 116 // first try to use a builder class if one is available 117 try { 118 LOGGER.debug("Building Plugin[name={}, class={}]. Searching for builder factory method...", pluginType.getElementName(), 119 pluginType.getPluginClass().getName()); 120 final Builder<?> builder = createBuilder(this.clazz); 121 if (builder != null) { 122 injectFields(builder); 123 final Object result = builder.build(); 124 LOGGER.debug("Built Plugin[name={}] OK from builder factory method.", pluginType.getElementName()); 125 return result; 126 } 127 } catch (final Exception e) { 128 LOGGER.error("Unable to inject fields into builder class for plugin type {}, element {}.", this.clazz, 129 node.getName(), e); 130 } 131 // or fall back to factory method if no builder class is available 132 try { 133 LOGGER.debug("Still building Plugin[name={}, class={}]. Searching for factory method...", 134 pluginType.getElementName(), pluginType.getPluginClass().getName()); 135 final Method factory = findFactoryMethod(this.clazz); 136 final Object[] params = generateParameters(factory); 137 final Object plugin = factory.invoke(null, params); 138 LOGGER.debug("Built Plugin[name={}] OK from factory method.", pluginType.getElementName()); 139 return plugin; 140 } catch (final Exception e) { 141 LOGGER.error("Unable to invoke factory method in class {} for element {}.", this.clazz, this.node.getName(), 142 e); 143 return null; 144 } 145 } 146 147 private void verify() { 148 Assert.requireNonNull(this.configuration, "No Configuration object was set."); 149 Assert.requireNonNull(this.node, "No Node object was set."); 150 } 151 152 private static Builder<?> createBuilder(final Class<?> clazz) 153 throws InvocationTargetException, IllegalAccessException { 154 for (final Method method : clazz.getDeclaredMethods()) { 155 if (method.isAnnotationPresent(PluginBuilderFactory.class) && 156 Modifier.isStatic(method.getModifiers()) && 157 TypeUtil.isAssignable(Builder.class, method.getGenericReturnType())) { 158 ReflectionUtil.makeAccessible(method); 159 @SuppressWarnings("unchecked") 160 final Builder<?> builder = (Builder<?>) method.invoke(null); 161 LOGGER.debug("Found builder factory method [{}]: {}.", method.getName(), method); 162 return builder; 163 } 164 } 165 LOGGER.debug("No builder factory method found in class {}. Going to try finding a factory method instead.", 166 clazz.getName()); 167 return null; 168 } 169 170 private void injectFields(final Builder<?> builder) throws IllegalAccessException { 171 final Field[] fields = builder.getClass().getDeclaredFields(); 172 AccessibleObject.setAccessible(fields, true); 173 final StringBuilder log = new StringBuilder(); 174 boolean invalid = false; 175 for (final Field field : fields) { 176 log.append(log.length() == 0 ? "with params(" : ", "); 177 final Annotation[] annotations = field.getDeclaredAnnotations(); 178 final String[] aliases = extractPluginAliases(annotations); 179 for (final Annotation a : annotations) { 180 if (a instanceof PluginAliases) { 181 continue; // already processed 182 } 183 final PluginVisitor<? extends Annotation> visitor = 184 PluginVisitors.findVisitor(a.annotationType()); 185 if (visitor != null) { 186 final Object value = visitor.setAliases(aliases) 187 .setAnnotation(a) 188 .setConversionType(field.getType()) 189 .setStrSubstitutor(event == null 190 ? new ConfigurationStrSubstitutor(configuration.getStrSubstitutor()) 191 : configuration.getStrSubstitutor()) 192 .setMember(field) 193 .visit(configuration, node, event, log); 194 // don't overwrite default values if the visitor gives us no value to inject 195 if (value != null) { 196 field.set(builder, value); 197 } 198 } 199 } 200 final Collection<ConstraintValidator<?>> validators = 201 ConstraintValidators.findValidators(annotations); 202 final Object value = field.get(builder); 203 for (final ConstraintValidator<?> validator : validators) { 204 if (!validator.isValid(value)) { 205 invalid = true; 206 } 207 } 208 } 209 if (log.length() > 0) { 210 log.append(')'); 211 } 212 LOGGER.debug("Calling build() on class {} for element {} {}", builder.getClass(), node.getName(), 213 log.toString()); 214 if (invalid) { 215 throw new ConfigurationException("Arguments given for element " + node.getName() + " are invalid"); 216 } 217 checkForRemainingAttributes(); 218 verifyNodeChildrenUsed(); 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 LOGGER.debug("Found factory method [{}]: {}.", method.getName(), method); 226 ReflectionUtil.makeAccessible(method); 227 return method; 228 } 229 } 230 throw new IllegalStateException("No factory method found for class " + clazz.getName()); 231 } 232 233 private Object[] generateParameters(final Method factory) { 234 final StringBuilder log = new StringBuilder(); 235 final Class<?>[] types = factory.getParameterTypes(); 236 final Annotation[][] annotations = factory.getParameterAnnotations(); 237 final Object[] args = new Object[annotations.length]; 238 boolean invalid = false; 239 for (int i = 0; i < annotations.length; i++) { 240 log.append(log.length() == 0 ? "with params(" : ", "); 241 final String[] aliases = extractPluginAliases(annotations[i]); 242 for (final Annotation a : annotations[i]) { 243 if (a instanceof PluginAliases) { 244 continue; // already processed 245 } 246 final PluginVisitor<? extends Annotation> visitor = PluginVisitors.findVisitor( 247 a.annotationType()); 248 if (visitor != null) { 249 final Object value = visitor.setAliases(aliases) 250 .setAnnotation(a) 251 .setConversionType(types[i]) 252 .setStrSubstitutor(event == null 253 ? new ConfigurationStrSubstitutor(configuration.getStrSubstitutor()) 254 : configuration.getStrSubstitutor()) 255 .setMember(factory) 256 .visit(configuration, node, event, log); 257 // don't overwrite existing values if the visitor gives us no value to inject 258 if (value != null) { 259 args[i] = value; 260 } 261 } 262 } 263 final Collection<ConstraintValidator<?>> validators = 264 ConstraintValidators.findValidators(annotations[i]); 265 final Object value = args[i]; 266 for (final ConstraintValidator<?> validator : validators) { 267 if (!validator.isValid(value)) { 268 invalid = true; 269 } 270 } 271 } 272 if (log.length() > 0) { 273 log.append(')'); 274 } 275 checkForRemainingAttributes(); 276 verifyNodeChildrenUsed(); 277 LOGGER.debug("Calling {} on class {} for element {} {}", factory.getName(), clazz.getName(), node.getName(), 278 log.toString()); 279 if (invalid) { 280 throw new ConfigurationException("Arguments given for element " + node.getName() + " are invalid"); 281 } 282 return args; 283 } 284 285 private static String[] extractPluginAliases(final Annotation... parmTypes) { 286 String[] aliases = null; 287 for (final Annotation a : parmTypes) { 288 if (a instanceof PluginAliases) { 289 aliases = ((PluginAliases) a).value(); 290 } 291 } 292 return aliases; 293 } 294 295 private void checkForRemainingAttributes() { 296 final Map<String, String> attrs = node.getAttributes(); 297 if (!attrs.isEmpty()) { 298 final StringBuilder sb = new StringBuilder(); 299 for (final String key : attrs.keySet()) { 300 if (sb.length() == 0) { 301 sb.append(node.getName()); 302 sb.append(" contains "); 303 if (attrs.size() == 1) { 304 sb.append("an invalid element or attribute "); 305 } else { 306 sb.append("invalid attributes "); 307 } 308 } else { 309 sb.append(", "); 310 } 311 StringBuilders.appendDqValue(sb, key); 312 313 } 314 LOGGER.error(sb.toString()); 315 } 316 } 317 318 private void verifyNodeChildrenUsed() { 319 final List<Node> children = node.getChildren(); 320 if (!(pluginType.isDeferChildren() || children.isEmpty())) { 321 for (final Node child : children) { 322 final String nodeType = node.getType().getElementName(); 323 final String start = nodeType.equals(node.getName()) ? node.getName() : nodeType + ' ' + node.getName(); 324 LOGGER.error("{} has no parameter that matches element {}", start, child.getName()); 325 } 326 } 327 } 328}