| /* |
| * 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. |
| */ |
| package org.apache.logging.log4j.layout.template.json.resolver; |
| |
| import org.apache.logging.log4j.Logger; |
| import org.apache.logging.log4j.core.LogEvent; |
| import org.apache.logging.log4j.layout.template.json.JsonTemplateLayout; |
| import org.apache.logging.log4j.layout.template.json.JsonTemplateLayoutDefaults; |
| import org.apache.logging.log4j.layout.template.json.util.JsonWriter; |
| import org.apache.logging.log4j.status.StatusLogger; |
| |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.regex.Pattern; |
| import java.util.regex.PatternSyntaxException; |
| |
| /** |
| * Exception resolver. |
| * <p> |
| * Note that this resolver is toggled by {@link |
| * JsonTemplateLayout.Builder#setStackTraceEnabled(boolean) stackTraceEnabled} |
| * layout configuration, which is by default populated from <tt>log4j.layout.jsonTemplate.stackTraceEnabled</tt> |
| * system property. |
| * |
| * <h3>Configuration</h3> |
| * |
| * <pre> |
| * config = field , [ stringified ] , [ stackTrace ] |
| * field = "field" -> ( "className" | "message" | "stackTrace" ) |
| * |
| * stackTrace = "stackTrace" -> ( |
| * [ stringified ] |
| * , [ elementTemplate ] |
| * ) |
| * |
| * stringified = "stringified" -> ( boolean | truncation ) |
| * truncation = "truncation" -> ( |
| * [ suffix ] |
| * , [ pointMatcherStrings ] |
| * , [ pointMatcherRegexes ] |
| * ) |
| * suffix = "suffix" -> string |
| * pointMatcherStrings = "pointMatcherStrings" -> string[] |
| * pointMatcherRegexes = "pointMatcherRegexes" -> string[] |
| * |
| * elementTemplate = "elementTemplate" -> object |
| * </pre> |
| * |
| * <tt>stringified</tt> is set to <tt>false</tt> by default. |
| * <tt>stringified</tt> at the root level is <b>deprecated</b> in favor of |
| * <tt>stackTrace.stringified</tt>, which has precedence if both are provided. |
| * <p> |
| * <tt>pointMatcherStrings</tt> and <tt>pointMatcherRegexes</tt> enable the |
| * truncation of stringified stack traces after the given matching point. If |
| * both parameters are provided, <tt>pointMatcherStrings</tt> will be checked |
| * first. |
| * <p> |
| * If a stringified stack trace truncation takes place, it will be indicated |
| * with <tt>suffix</tt>, which by default is set to the configured |
| * <tt>truncatedStringSuffix</tt> in the layout, unless explicitly provided. |
| * <p> |
| * <tt>elementTemplate</tt> is an object describing the template to be used |
| * while resolving the {@link StackTraceElement} array. If <tt>stringified</tt> |
| * is set to <tt>true</tt>, <tt>elementTemplate</tt> will be discarded. By |
| * default, <tt>elementTemplate</tt> is set to <tt>null</tt> and rather |
| * populated from the layout configuration. That is, the stack trace element |
| * template can also be provided using {@link JsonTemplateLayout.Builder#setStackTraceElementTemplate(String) stackTraceElementTemplate} |
| * and {@link JsonTemplateLayout.Builder#setStackTraceElementTemplateUri(String) setStackTraceElementTemplateUri} |
| * layout configuration parameters. The template to be employed is determined |
| * in the following order: |
| * <ol> |
| * <li><tt>elementTemplate</tt> provided in the resolver configuration |
| * <li><tt>stackTraceElementTemplate</tt> parameter from layout configuration |
| * (the default is populated from <tt>log4j.layout.jsonTemplate.stackTraceElementTemplate</tt> |
| * system property) |
| * <li><tt>stackTraceElementTemplateUri</tt> parameter from layout configuration |
| * (the default is populated from <tt>log4j.layout.jsonTemplate.stackTraceElementTemplateUri</tt> |
| * system property) |
| * </ol> |
| * <p> |
| * See {@link StackTraceElementResolver} |
| * for the list of available resolvers in a stack trace element template. |
| * |
| * <h3>Examples</h3> |
| * |
| * Resolve <tt>logEvent.getThrown().getClass().getCanonicalName()</tt>: |
| * |
| * <pre> |
| * { |
| * "$resolver": "exception", |
| * "field": "className" |
| * } |
| * </pre> |
| * |
| * Resolve the stack trace into a list of <tt>StackTraceElement</tt> objects: |
| * |
| * <pre> |
| * { |
| * "$resolver": "exception", |
| * "field": "stackTrace" |
| * } |
| * </pre> |
| * |
| * Resolve the stack trace into a string field: |
| * |
| * <pre> |
| * { |
| * "$resolver": "exception", |
| * "field": "stackTrace", |
| * "stackTrace": { |
| * "stringified": true |
| * } |
| * } |
| * </pre> |
| * |
| * Resolve the stack trace into a string field |
| * such that the content will be truncated after the given point matcher: |
| * |
| * <pre> |
| * { |
| * "$resolver": "exception", |
| * "field": "stackTrace", |
| * "stackTrace": { |
| * "stringified": { |
| * "truncation": { |
| * "suffix": ">", |
| * "pointMatcherStrings": ["at javax.servlet.http.HttpServlet.service"] |
| * } |
| * } |
| * } |
| * } |
| * </pre> |
| * |
| * Resolve the stack trace into an object described by the provided stack trace |
| * element template: |
| * |
| * <pre> |
| * { |
| * "$resolver": "exception", |
| * "field": "stackTrace", |
| * "stackTrace": { |
| * "elementTemplate": { |
| * "class": { |
| * "$resolver": "stackTraceElement", |
| * "field": "className" |
| * }, |
| * "method": { |
| * "$resolver": "stackTraceElement", |
| * "field": "methodName" |
| * }, |
| * "file": { |
| * "$resolver": "stackTraceElement", |
| * "field": "fileName" |
| * }, |
| * "line": { |
| * "$resolver": "stackTraceElement", |
| * "field": "lineNumber" |
| * } |
| * } |
| * } |
| * } |
| * </pre> |
| * |
| * @see JsonTemplateLayout.Builder#getTruncatedStringSuffix() |
| * @see JsonTemplateLayoutDefaults#getTruncatedStringSuffix() |
| * @see JsonTemplateLayout.Builder#getStackTraceElementTemplate() |
| * @see JsonTemplateLayoutDefaults#getStackTraceElementTemplate() |
| * @see JsonTemplateLayout.Builder#getStackTraceElementTemplateUri() |
| * @see JsonTemplateLayoutDefaults#getStackTraceElementTemplateUri() |
| * @see ExceptionRootCauseResolver |
| * @see StackTraceElementResolver |
| */ |
| public class ExceptionResolver implements EventResolver { |
| |
| private static final Logger LOGGER = StatusLogger.getLogger(); |
| |
| private static final EventResolver NULL_RESOLVER = |
| (ignored, jsonGenerator) -> jsonGenerator.writeNull(); |
| |
| private final boolean stackTraceEnabled; |
| |
| private final EventResolver internalResolver; |
| |
| ExceptionResolver( |
| final EventResolverContext context, |
| final TemplateResolverConfig config) { |
| this.stackTraceEnabled = context.isStackTraceEnabled(); |
| this.internalResolver = createInternalResolver(context, config); |
| } |
| |
| EventResolver createInternalResolver( |
| final EventResolverContext context, |
| final TemplateResolverConfig config) { |
| final String fieldName = config.getString("field"); |
| if ("className".equals(fieldName)) { |
| return createClassNameResolver(); |
| } else if ("message".equals(fieldName)) { |
| return createMessageResolver(); |
| } else if ("stackTrace".equals(fieldName)) { |
| return createStackTraceResolver(context, config); |
| } |
| throw new IllegalArgumentException("unknown field: " + config); |
| } |
| |
| private EventResolver createClassNameResolver() { |
| return (final LogEvent logEvent, final JsonWriter jsonWriter) -> { |
| final Throwable exception = extractThrowable(logEvent); |
| if (exception == null) { |
| jsonWriter.writeNull(); |
| } else { |
| String exceptionClassName = exception.getClass().getCanonicalName(); |
| jsonWriter.writeString(exceptionClassName); |
| } |
| }; |
| } |
| |
| private EventResolver createMessageResolver() { |
| return (final LogEvent logEvent, final JsonWriter jsonWriter) -> { |
| final Throwable exception = extractThrowable(logEvent); |
| if (exception == null) { |
| jsonWriter.writeNull(); |
| } else { |
| String exceptionMessage = exception.getMessage(); |
| jsonWriter.writeString(exceptionMessage); |
| } |
| }; |
| } |
| |
| private EventResolver createStackTraceResolver( |
| final EventResolverContext context, |
| final TemplateResolverConfig config) { |
| if (!context.isStackTraceEnabled()) { |
| return NULL_RESOLVER; |
| } |
| final boolean stringified = isStackTraceStringified(config); |
| return stringified |
| ? createStackTraceStringResolver(context, config) |
| : createStackTraceObjectResolver(context, config); |
| } |
| |
| private static boolean isStackTraceStringified( |
| final TemplateResolverConfig config) { |
| final Boolean stringifiedOld = config.getBoolean("stringified"); |
| if (stringifiedOld != null) { |
| LOGGER.warn( |
| "\"stringified\" flag at the root level of an exception " + |
| "[root cause] resolver is deprecated in favor of " + |
| "\"stackTrace.stringified\""); |
| } |
| final Object stringifiedNew = |
| config.getObject(new String[]{"stackTrace", "stringified"}); |
| if (stringifiedOld == null && stringifiedNew == null) { |
| return false; |
| } else if (stringifiedNew == null) { |
| return stringifiedOld; |
| } else { |
| return !(stringifiedNew instanceof Boolean) || (boolean) stringifiedNew; |
| } |
| } |
| |
| private EventResolver createStackTraceStringResolver( |
| final EventResolverContext context, |
| final TemplateResolverConfig config) { |
| |
| // Read the configuration. |
| final String truncationSuffix = |
| readTruncationSuffix(context, config); |
| final List<String> truncationPointMatcherStrings = |
| readTruncationPointMatcherStrings(config); |
| final List<String> truncationPointMatcherRegexes = |
| readTruncationPointMatcherRegexes(config); |
| |
| // Create the resolver. |
| final StackTraceStringResolver resolver = |
| new StackTraceStringResolver( |
| context, |
| truncationSuffix, |
| truncationPointMatcherStrings, |
| truncationPointMatcherRegexes); |
| |
| // Create the null-protected resolver. |
| return (final LogEvent logEvent, final JsonWriter jsonWriter) -> { |
| final Throwable exception = extractThrowable(logEvent); |
| if (exception == null) { |
| jsonWriter.writeNull(); |
| } else { |
| resolver.resolve(exception, jsonWriter); |
| } |
| }; |
| |
| } |
| |
| private static String readTruncationSuffix( |
| final EventResolverContext context, |
| final TemplateResolverConfig config) { |
| final String suffix = config.getString( |
| new String[]{"stackTrace", "stringified", "truncation", "suffix"}); |
| return suffix != null |
| ? suffix |
| : context.getTruncatedStringSuffix(); |
| } |
| |
| private static List<String> readTruncationPointMatcherStrings( |
| final TemplateResolverConfig config) { |
| List<String> strings = config.getList( |
| new String[]{"stackTrace", "stringified", "truncation", "pointMatcherStrings"}, |
| String.class); |
| if (strings == null) { |
| strings = Collections.emptyList(); |
| } |
| return strings; |
| } |
| |
| private static List<String> readTruncationPointMatcherRegexes( |
| final TemplateResolverConfig config) { |
| |
| // Extract the regexes. |
| List<String> regexes = config.getList( |
| new String[]{"stackTrace", "stringified", "truncation", "pointMatcherRegexes"}, |
| String.class); |
| if (regexes == null) { |
| regexes = Collections.emptyList(); |
| } |
| |
| // Check the regex syntax. |
| for (int i = 0; i < regexes.size(); i++) { |
| final String regex = regexes.get(i); |
| try { |
| Pattern.compile(regex); |
| } catch (final PatternSyntaxException error) { |
| final String message = String.format( |
| "invalid truncation point matcher regex at index %d: %s", |
| i, regex); |
| throw new IllegalArgumentException(message, error); |
| } |
| } |
| |
| // Return the extracted regexes. |
| return regexes; |
| |
| } |
| |
| private static final Map<String, StackTraceElementResolverFactory> STACK_TRACE_ELEMENT_RESOLVER_FACTORY_BY_NAME; |
| |
| static { |
| final StackTraceElementResolverFactory stackTraceElementResolverFactory = |
| StackTraceElementResolverFactory.getInstance(); |
| STACK_TRACE_ELEMENT_RESOLVER_FACTORY_BY_NAME = |
| Collections.singletonMap( |
| stackTraceElementResolverFactory.getName(), |
| stackTraceElementResolverFactory); |
| } |
| |
| private EventResolver createStackTraceObjectResolver( |
| final EventResolverContext context, |
| final TemplateResolverConfig config) { |
| final TemplateResolver<StackTraceElement> stackTraceElementResolver = |
| createStackTraceElementResolver(context, config); |
| final StackTraceObjectResolver stackTraceResolver = |
| new StackTraceObjectResolver(stackTraceElementResolver); |
| return (final LogEvent logEvent, final JsonWriter jsonWriter) -> { |
| final Throwable throwable = extractThrowable(logEvent); |
| if (throwable == null) { |
| jsonWriter.writeNull(); |
| } else { |
| stackTraceResolver.resolve(throwable, jsonWriter); |
| } |
| }; |
| } |
| |
| private static TemplateResolver<StackTraceElement> createStackTraceElementResolver( |
| final EventResolverContext context, |
| final TemplateResolverConfig config) { |
| final StackTraceElementResolverStringSubstitutor substitutor = |
| new StackTraceElementResolverStringSubstitutor( |
| context.getSubstitutor().getInternalSubstitutor()); |
| final StackTraceElementResolverContext stackTraceElementResolverContext = |
| StackTraceElementResolverContext |
| .newBuilder() |
| .setResolverFactoryByName(STACK_TRACE_ELEMENT_RESOLVER_FACTORY_BY_NAME) |
| .setSubstitutor(substitutor) |
| .setJsonWriter(context.getJsonWriter()) |
| .build(); |
| final String stackTraceElementTemplate = |
| findEffectiveStackTraceElementTemplate(context, config); |
| return TemplateResolvers.ofTemplate( |
| stackTraceElementResolverContext, |
| stackTraceElementTemplate); |
| } |
| |
| private static String findEffectiveStackTraceElementTemplate( |
| final EventResolverContext context, |
| final TemplateResolverConfig config) { |
| |
| // First, check the template configured in the resolver configuration. |
| final Object stackTraceElementTemplateObject = |
| config.getObject(new String[]{"stackTrace", "elementTemplate"}); |
| if (stackTraceElementTemplateObject != null) { |
| final JsonWriter jsonWriter = context.getJsonWriter(); |
| return jsonWriter.use(() -> jsonWriter.writeValue(stackTraceElementTemplateObject)); |
| } |
| |
| // Otherwise, use the template provided in the context. |
| return context.getStackTraceElementTemplate(); |
| |
| } |
| |
| Throwable extractThrowable(final LogEvent logEvent) { |
| return logEvent.getThrown(); |
| } |
| |
| static String getName() { |
| return "exception"; |
| } |
| |
| @Override |
| public boolean isResolvable() { |
| return stackTraceEnabled; |
| } |
| |
| @Override |
| public boolean isResolvable(final LogEvent logEvent) { |
| return stackTraceEnabled && logEvent.getThrown() != null; |
| } |
| |
| @Override |
| public void resolve( |
| final LogEvent logEvent, |
| final JsonWriter jsonWriter) { |
| internalResolver.resolve(logEvent, jsonWriter); |
| } |
| |
| } |
