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Provides logback encoders, layouts, and appenders to log in JSON and other formats supported by Jackson
/**
* Licensed 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 net.logstash.logback.stacktrace;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.regex.Pattern;
import net.logstash.logback.CachingAbbreviator;
import net.logstash.logback.NullAbbreviator;
import ch.qos.logback.access.PatternLayout;
import ch.qos.logback.classic.pattern.Abbreviator;
import ch.qos.logback.classic.pattern.TargetLengthBasedClassNameAbbreviator;
import ch.qos.logback.classic.pattern.ThrowableHandlingConverter;
import ch.qos.logback.classic.pattern.ThrowableProxyConverter;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.classic.spi.IThrowableProxy;
import ch.qos.logback.classic.spi.StackTraceElementProxy;
import ch.qos.logback.classic.spi.ThrowableProxyUtil;
import ch.qos.logback.core.CoreConstants;
import ch.qos.logback.core.boolex.EvaluationException;
import ch.qos.logback.core.boolex.EventEvaluator;
import ch.qos.logback.core.status.ErrorStatus;
/**
* A {@link ThrowableHandlingConverter} (similar to logback's {@link ThrowableProxyConverter})
* that formats stacktraces by doing the following:
*
*
* - Limits the number of stackTraceElements per throwable
* (applies to each individual throwable. e.g. caused-bys and suppressed).
* See {@link #maxDepthPerThrowable}.
* - Limits the total length in characters of the trace.
* See {@link #maxLength}.
* - Abbreviates class names based on the {@link #shortenedClassNameLength}.
* See {@link #shortenedClassNameLength}.
* - Filters out consecutive unwanted stackTraceElements based on regular expressions.
* See {@link #excludes}.
* - Uses evaluators to determine if the stacktrace should be logged.
* See {@link #evaluators}.
* - Outputs in either 'normal' order (root-cause-last), or root-cause-first.
* See {@link #rootCauseFirst}.
*
*
*
* To use this with a {@link PatternLayout}, you must configure conversionRule
* as described here.
* Options can be specified in the pattern in the following order:
*
* - maxDepthPerThrowable = "full" or "short" or an integer value
* - maxLength = "full" or "short" or an integer value
* - shortenedClassNameLength = "full" or "short" or an integer value
*
* If any other remaining options are "rootFirst",
* then the converter awill be configured as root-cause-first.
* If any other remaining options equal to an evaluator name,
* then the evaluator will be used to determine if the stacktrace should be printed.
* Other options will be interpreted as exclusion regexes.
*
* For example,
*
* {@code
*
*
* [%thread] - %msg%n%stack{5,1024,10,rootFirst,regex1,regex2,evaluatorName}
*
*
* }
*
*
*
*
*/
public class ShortenedThrowableConverter extends ThrowableHandlingConverter {
public static final int FULL_MAX_DEPTH_PER_THROWABLE = Integer.MAX_VALUE;
public static final int SHORT_MAX_DEPTH_PER_THROWABLE = 3;
public static final int DEFAULT_MAX_DEPTH_PER_THROWABLE = 25;
public static final int FULL_MAX_LENGTH = Integer.MAX_VALUE;
public static final int SHORT_MAX_LENGTH = 1024;
public static final int DEFAULT_MAX_LENGTH = FULL_MAX_LENGTH;
public static final int FULL_CLASS_NAME_LENGTH = Integer.MAX_VALUE;
public static final int SHORT_CLASS_NAME_LENGTH = 10;
public static final int DEFAULT_CLASS_NAME_LENGTH = FULL_CLASS_NAME_LENGTH;
private static final String ELLIPSIS = "...";
private static final int BUFFER_INITIAL_CAPACITY = 4096;
private static final String OPTION_VALUE_FULL = "full";
private static final String OPTION_VALUE_SHORT = "short";
private static final String OPTION_VALUE_ROOT_FIRST = "rootFirst";
private static final int OPTION_INDEX_MAX_DEPTH = 0;
private static final int OPTION_INDEX_SHORTENED_CLASS_NAME = 1;
private static final int OPTION_INDEX_MAX_LENGTH = 2;
private AtomicInteger errorCount = new AtomicInteger();
/**
* Maximum number of stackTraceElements printed per throwable.
*/
private int maxDepthPerThrowable = DEFAULT_MAX_DEPTH_PER_THROWABLE;
/**
* Maximum number of characters in the entire stacktrace.
*/
private int maxLength = DEFAULT_MAX_LENGTH;
/**
* Will try to shorten class name lengths to less than this value
*/
private int shortenedClassNameLength = DEFAULT_CLASS_NAME_LENGTH;
/**
* Abbreviator that will shorten the classnames if {@link #shortenedClassNameLength}
* is set less than {@link #FULL_CLASS_NAME_LENGTH}
*/
private Abbreviator abbreviator = NullAbbreviator.INSTANCE;
/**
* Patterns used to determine which stacktrace elements to exclude.
*
* The strings being matched against are in the form "fullyQualifiedClassName.methodName"
* (e.g. "java.lang.Object.toString").
*
* Note that these elements will only be excluded if and only if
* more than one consecutive line matches an exclusion pattern.
*/
private List excludes = new ArrayList(5);
/**
* True to print the root cause first. False to print exceptions normally (root cause last).
*/
private boolean rootCauseFirst;
/**
* Evaluators that determine if the stacktrace should be logged.
*/
private List> evaluators = new ArrayList>(1);
@Override
public void start() {
parseOptions();
super.start();
}
private void parseOptions() {
List optionList = getOptionList();
if (optionList == null) {
return;
}
final int optionListSize = optionList.size();
for (int i = 0; i < optionListSize; i++) {
String option = optionList.get(i);
switch (i) {
case OPTION_INDEX_MAX_DEPTH:
setMaxDepthPerThrowable(parseIntegerOptionValue(option, FULL_MAX_DEPTH_PER_THROWABLE, SHORT_MAX_DEPTH_PER_THROWABLE, DEFAULT_MAX_DEPTH_PER_THROWABLE));
break;
case OPTION_INDEX_SHORTENED_CLASS_NAME:
setShortenedClassNameLength(parseIntegerOptionValue(option, FULL_CLASS_NAME_LENGTH, SHORT_CLASS_NAME_LENGTH, DEFAULT_CLASS_NAME_LENGTH));
break;
case OPTION_INDEX_MAX_LENGTH:
setMaxLength(parseIntegerOptionValue(option, FULL_MAX_LENGTH, SHORT_MAX_LENGTH, DEFAULT_MAX_LENGTH));
break;
default:
/*
* Remaining options are either
* - "rootFirst" - indicating that stacks should be printed root-cause first
* - evaluator name - name of evaluators that will determine if the stacktrace is ignored
* - exclusion pattern - pattern for stack trace elements to exclude
*/
if (OPTION_VALUE_ROOT_FIRST.equals(option)) {
setRootCauseFirst(true);
} else {
@SuppressWarnings("rawtypes")
Map evaluatorMap = (Map) getContext().getObject(CoreConstants.EVALUATOR_MAP);
@SuppressWarnings("unchecked")
EventEvaluator evaluator = (evaluatorMap != null)
? (EventEvaluator) evaluatorMap.get(option)
: null;
if (evaluator != null) {
addEvaluator(evaluator);
} else {
addExclude(option);
}
}
break;
}
}
}
private int parseIntegerOptionValue(String option, int valueIfFull, int valueIfShort, int valueIfNonParsable) {
if (OPTION_VALUE_FULL.equals(option)) {
return valueIfFull;
} else if (OPTION_VALUE_SHORT.equals(option)) {
return valueIfShort;
} else {
try {
return Integer.parseInt(option);
} catch (NumberFormatException nfe) {
addError("Could not parse [" + option + "] as an integer");
return valueIfNonParsable;
}
}
}
@Override
public String convert(ILoggingEvent event) {
IThrowableProxy throwableProxy = event.getThrowableProxy();
if (throwableProxy == null || isExcludedByEvaluator(event)) {
return CoreConstants.EMPTY_STRING;
}
/*
* The extra 100 gives a little more buffer room since we actually
* go over the maxLength before detecting it and truncating.
*/
StringBuilder builder = new StringBuilder(Math.min(BUFFER_INITIAL_CAPACITY, Math.max(Integer.MAX_VALUE, this.maxLength + 100)));
if (rootCauseFirst) {
appendRootCauseFirst(builder, null, ThrowableProxyUtil.REGULAR_EXCEPTION_INDENT, throwableProxy);
} else {
appendRootCauseLast(builder, null, ThrowableProxyUtil.REGULAR_EXCEPTION_INDENT, throwableProxy);
}
if (builder.length() > maxLength) {
builder.setLength(maxLength - ELLIPSIS.length());
builder.append(ELLIPSIS);
}
return builder.toString();
}
/**
* Return true if any evaluator returns true, indicating that
* the stack trace should not be logged.
*/
private boolean isExcludedByEvaluator(ILoggingEvent event) {
for (int i = 0; i < evaluators.size(); i++) {
EventEvaluator evaluator = evaluators.get(i);
try {
if (evaluator.evaluate(event)) {
return true;
}
} catch (EvaluationException eex) {
int errors = errorCount.incrementAndGet();
if (errors < CoreConstants.MAX_ERROR_COUNT) {
addError(String.format("Exception thrown for evaluator named [%s]", evaluator.getName()), eex);
} else if (errors == CoreConstants.MAX_ERROR_COUNT) {
ErrorStatus errorStatus = new ErrorStatus(
String.format("Exception thrown for evaluator named [%s]", evaluator.getName()), this, eex);
errorStatus.add(new ErrorStatus(
"This was the last warning about this evaluator's errors."
+ "We don't want the StatusManager to get flooded.",
this));
addStatus(errorStatus);
}
}
}
return false;
}
/**
* Appends a throwable and recursively appends its causedby/suppressed throwables
* in "normal" order (Root cause last).
*/
private void appendRootCauseLast(
StringBuilder builder,
String prefix,
int indent,
IThrowableProxy throwableProxy) {
if (throwableProxy == null || builder.length() > maxLength) {
return;
}
appendFirstLine(builder, prefix, indent, throwableProxy);
appendStackTraceElements(builder, indent, throwableProxy);
IThrowableProxy[] suppressedThrowableProxies = throwableProxy.getSuppressed();
if (suppressedThrowableProxies != null) {
for (IThrowableProxy suppressedThrowableProxy : suppressedThrowableProxies) {
appendRootCauseLast(builder, CoreConstants.SUPPRESSED, indent + ThrowableProxyUtil.SUPPRESSED_EXCEPTION_INDENT, suppressedThrowableProxy);
}
}
appendRootCauseLast(builder, CoreConstants.CAUSED_BY, indent, throwableProxy.getCause());
}
/**
* Appends a throwable and recursively appends its causedby/suppressed throwables
* in "reverse" order (Root cause first).
*/
private void appendRootCauseFirst(
StringBuilder builder,
String prefix,
int indent,
IThrowableProxy throwableProxy) {
if (throwableProxy == null || builder.length() > maxLength) {
return;
}
if (throwableProxy.getCause() != null) {
appendRootCauseFirst(builder, prefix, indent, throwableProxy.getCause());
prefix = CoreConstants.WRAPPED_BY;
}
appendFirstLine(builder, prefix, indent, throwableProxy);
appendStackTraceElements(builder, indent, throwableProxy);
IThrowableProxy[] suppressedThrowableProxies = throwableProxy.getSuppressed();
if (suppressedThrowableProxies != null) {
for (IThrowableProxy suppressedThrowableProxy : suppressedThrowableProxies) {
appendRootCauseFirst(builder, CoreConstants.SUPPRESSED, indent + ThrowableProxyUtil.SUPPRESSED_EXCEPTION_INDENT, suppressedThrowableProxy);
}
}
}
/**
* Appends the frames of the throwable.
*/
private void appendStackTraceElements(StringBuilder builder, int indent, IThrowableProxy throwableProxy) {
if (builder.length() > maxLength) {
return;
}
StackTraceElementProxy[] stackTraceElements = throwableProxy.getStackTraceElementProxyArray();
int commonFrames = throwableProxy.getCommonFrames();
boolean appendingExcluded = false;
int consecutiveExcluded = 0;
int appended = 0;
StackTraceElementProxy previousWrittenStackTraceElement = null;
for (int i = 0; i < stackTraceElements.length - commonFrames; i++) {
if (maxDepthPerThrowable > 0 && appended >= maxDepthPerThrowable) {
/*
* We reached the configure limit. Bail out.
*/
appendPlaceHolder(builder, indent, stackTraceElements.length - commonFrames - maxDepthPerThrowable, "frames truncated");
break;
}
StackTraceElementProxy stackTraceElement = stackTraceElements[i];
if (i <= 1 || isIncluded(stackTraceElement)) {
/*
* We should append this line.
*
* consecutiveExcluded will be > 0 if we were previously skipping lines based on excludes
*/
if (consecutiveExcluded >= 2) {
/*
* Multiple consecutive lines were excluded, so append a placeholder
*/
appendPlaceHolder(builder, indent, consecutiveExcluded, "frames excluded");
consecutiveExcluded = 0;
} else if (consecutiveExcluded == 1) {
/*
* We only excluded one line, so just go back and include it
* instead of printing the excluding message for it.
*/
appendingExcluded = true;
consecutiveExcluded = 0;
i -= 2;
continue;
}
appendStackTraceElement(builder, indent, stackTraceElement, previousWrittenStackTraceElement);
previousWrittenStackTraceElement = stackTraceElement;
appendingExcluded = false;
appended++;
} else if (appendingExcluded) {
/*
* We're going back and appending something we previously excluded
*/
appendStackTraceElement(builder, indent, stackTraceElement, previousWrittenStackTraceElement);
previousWrittenStackTraceElement = stackTraceElement;
appended++;
} else {
consecutiveExcluded++;
}
}
if (consecutiveExcluded > 0) {
/*
* We were excluding stuff at the end, so append a placeholder
*/
appendPlaceHolder(builder, indent, consecutiveExcluded, "frames excluded");
}
if (commonFrames > 0) {
/*
* Common frames found, append a placeholder
*/
appendPlaceHolder(builder, indent, commonFrames, "common frames omitted");
}
}
/**
* Appends a placeholder indicating that some frames were not written.
*/
private void appendPlaceHolder(StringBuilder builder, int indent, int consecutiveExcluded, String message) {
indent(builder, indent);
builder.append(ELLIPSIS)
.append(" ")
.append(consecutiveExcluded)
.append(" ")
.append(message)
.append(CoreConstants.LINE_SEPARATOR);
}
/**
* Return true if the stack trace element is included (i.e. doesn't match any exclude patterns).
*/
private boolean isIncluded(StackTraceElementProxy step) {
if (!excludes.isEmpty()) {
StackTraceElement stackTraceElement = step.getStackTraceElement();
String testString = stackTraceElement.getClassName() + "." + stackTraceElement.getMethodName();
for (Pattern exclusionPattern : excludes) {
if (exclusionPattern.matcher(testString).find()) {
return false;
}
}
}
return true;
}
/**
* Appends a single stack trace element.
*/
private void appendStackTraceElement(StringBuilder builder, int indent, StackTraceElementProxy step, StackTraceElementProxy previousStep) {
if (builder.length() > maxLength) {
return;
}
indent(builder, indent);
StackTraceElement stackTraceElement = step.getStackTraceElement();
String fileName = stackTraceElement.getFileName();
int lineNumber = stackTraceElement.getLineNumber();
builder.append("at ")
.append(abbreviator.abbreviate(stackTraceElement.getClassName()))
.append(".")
.append(stackTraceElement.getMethodName())
.append("(")
.append(fileName == null ? "Unknown Source" : fileName);
if (lineNumber >= 0) {
builder.append(":")
.append(lineNumber);
}
builder.append(")");
if (shouldAppendPackagingData(step, previousStep)) {
appendPackagingData(builder, step);
}
builder.append(CoreConstants.LINE_SEPARATOR);
}
/**
* Return true if packaging data should be appended for the current step.
*
* Packaging data for the current step is only appended if it differs
* from the packaging data from the previous step.
*/
private boolean shouldAppendPackagingData(StackTraceElementProxy step, StackTraceElementProxy previousStep) {
if (step == null || step.getClassPackagingData() == null) {
return false;
}
if (previousStep == null || previousStep.getClassPackagingData() == null) {
return true;
}
return !step.getClassPackagingData().equals(previousStep.getClassPackagingData());
}
private void appendPackagingData(StringBuilder builder, StackTraceElementProxy step) {
ThrowableProxyUtil.subjoinPackagingData(builder, step);
}
/**
* Appends the first line containing the prefix and throwable message
*/
private void appendFirstLine(StringBuilder builder, String prefix, int indent, IThrowableProxy throwableProxy) {
if (builder.length() > maxLength) {
return;
}
indent(builder, indent - 1);
if (prefix != null) {
builder.append(prefix);
}
builder.append(abbreviator.abbreviate(throwableProxy.getClassName()))
.append(": ")
.append(throwableProxy.getMessage())
.append(CoreConstants.LINE_SEPARATOR);
}
private void indent(StringBuilder builder, int indent) {
ThrowableProxyUtil.indent(builder, indent);
}
public int getShortenedClassNameLength() {
return shortenedClassNameLength;
}
public void setShortenedClassNameLength(int length) {
if (length <= 0) {
throw new IllegalArgumentException();
}
this.shortenedClassNameLength = length;
if (length < FULL_CLASS_NAME_LENGTH) {
abbreviator = new CachingAbbreviator(new TargetLengthBasedClassNameAbbreviator(this.shortenedClassNameLength));
} else {
abbreviator = NullAbbreviator.INSTANCE;
}
}
public int getMaxDepthPerThrowable() {
return maxDepthPerThrowable;
}
public void setMaxDepthPerThrowable(int maxDepthPerThrowable) {
if (maxDepthPerThrowable <= 0) {
throw new IllegalArgumentException();
}
this.maxDepthPerThrowable = maxDepthPerThrowable;
}
public void setMaxLength(int maxLength) {
if (maxLength <= 0) {
throw new IllegalArgumentException();
}
this.maxLength = maxLength;
}
public int getMaxLength() {
return maxLength;
}
public boolean isRootCauseFirst() {
return rootCauseFirst;
}
public void setRootCauseFirst(boolean rootCauseFirst) {
this.rootCauseFirst = rootCauseFirst;
}
public void addExclude(String exclusionPattern) {
excludes.add(Pattern.compile(exclusionPattern));
}
public void setExcludes(List exclusionPatterns) {
if (exclusionPatterns == null || exclusionPatterns.isEmpty()) {
this.excludes = new ArrayList(5);
} else {
this.excludes = new ArrayList(exclusionPatterns.size());
for (String pattern : exclusionPatterns) {
addExclude(pattern);
}
}
}
public List getExcludes() {
List exclusionPatterns = new ArrayList(excludes.size());
for (Pattern pattern : excludes) {
exclusionPatterns.add(pattern.pattern());
}
return exclusionPatterns;
}
public void addEvaluator(EventEvaluator evaluator) {
evaluators.add(evaluator);
}
public void setEvaluators(List> evaluators) {
if (evaluators == null || evaluators.isEmpty()) {
this.evaluators = new ArrayList>(1);
} else {
this.evaluators = new ArrayList>(evaluators);
}
}
public List> getEvaluators() {
return new ArrayList>(evaluators);
}
}