org.apache.logging.log4j.core.appender.ConsoleAppender Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of log4j-core Show documentation
Show all versions of log4j-core Show documentation
The Apache Log4j Implementation
/*
* 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.core.appender;
import org.apache.logging.log4j.core.Appender;
import org.apache.logging.log4j.core.Core;
import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.core.config.Property;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
import org.apache.logging.log4j.core.config.plugins.validation.constraints.Required;
import org.apache.logging.log4j.core.layout.PatternLayout;
import org.apache.logging.log4j.core.util.Booleans;
import org.apache.logging.log4j.core.util.CloseShieldOutputStream;
import org.apache.logging.log4j.core.util.Loader;
import org.apache.logging.log4j.core.util.Throwables;
import org.apache.logging.log4j.util.Chars;
import org.apache.logging.log4j.util.PropertiesUtil;
import java.io.*;
import java.lang.reflect.Constructor;
import java.nio.charset.Charset;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Appends log events to System.out or System.err using a layout specified by the user. The
* default target is System.out.
*
* TODO Accessing System.out or System.err as a byte stream instead of a writer bypasses the
* JVM's knowledge of the proper encoding. (RG) Encoding is handled within the Layout. Typically, a Layout will generate
* a String and then call getBytes which may use a configured encoding or the system default. OTOH, a Writer cannot
* print byte streams.
*
*/
@Plugin(name = ConsoleAppender.PLUGIN_NAME, category = Core.CATEGORY_NAME, elementType = Appender.ELEMENT_TYPE, printObject = true)
public final class ConsoleAppender extends AbstractOutputStreamAppender {
public static final String PLUGIN_NAME = "Console";
private static final String JANSI_CLASS = "org.fusesource.jansi.WindowsAnsiOutputStream";
private static ConsoleManagerFactory factory = new ConsoleManagerFactory();
private static final Target DEFAULT_TARGET = Target.SYSTEM_OUT;
private static final AtomicInteger COUNT = new AtomicInteger();
private final Target target;
/**
* Enumeration of console destinations.
*/
public enum Target {
/** Standard output. */
SYSTEM_OUT {
@Override
public Charset getDefaultCharset() {
// "sun.stdout.encoding" is only set when running from the console.
return getCharset("sun.stdout.encoding", Charset.defaultCharset());
}
},
/** Standard error output. */
SYSTEM_ERR {
@Override
public Charset getDefaultCharset() {
// "sun.stderr.encoding" is only set when running from the console.
return getCharset("sun.stderr.encoding", Charset.defaultCharset());
}
};
public abstract Charset getDefaultCharset();
protected Charset getCharset(final String property, final Charset defaultCharset) {
return new PropertiesUtil(PropertiesUtil.getSystemProperties()).getCharsetProperty(property, defaultCharset);
}
}
private ConsoleAppender(final String name, final Layout layout, final Filter filter,
final OutputStreamManager manager, final boolean ignoreExceptions, final Target target,
final Property[] properties) {
super(name, layout, filter, ignoreExceptions, true, properties, manager);
this.target = target;
}
/**
* Creates a Console Appender.
*
* @param layout The layout to use (required).
* @param filter The Filter or null.
* @param targetStr The target ("SYSTEM_OUT" or "SYSTEM_ERR"). The default is "SYSTEM_OUT".
* @param name The name of the Appender (required).
* @param follow If true will follow changes to the underlying output stream.
* @param ignore If {@code "true"} (default) exceptions encountered when appending events are logged; otherwise they
* are propagated to the caller.
* @return The ConsoleAppender.
* @deprecated Deprecated in 2.7; use {@link #newBuilder()}.
*/
@Deprecated
public static ConsoleAppender createAppender(Layout layout,
final Filter filter,
final String targetStr,
final String name,
final String follow,
final String ignore) {
if (name == null) {
LOGGER.error("No name provided for ConsoleAppender");
return null;
}
if (layout == null) {
layout = PatternLayout.createDefaultLayout();
}
final boolean isFollow = Boolean.parseBoolean(follow);
final boolean ignoreExceptions = Booleans.parseBoolean(ignore, true);
final Target target = targetStr == null ? DEFAULT_TARGET : Target.valueOf(targetStr);
return new ConsoleAppender(name, layout, filter, getManager(target, isFollow, false, layout), ignoreExceptions, target, null);
}
/**
* Creates a Console Appender.
*
* @param layout The layout to use (required).
* @param filter The Filter or null.
* @param target The target (SYSTEM_OUT or SYSTEM_ERR). The default is SYSTEM_OUT.
* @param name The name of the Appender (required).
* @param follow If true will follow changes to the underlying output stream.
* @param direct If true will write directly to {@link java.io.FileDescriptor} and bypass
* {@link System#out}/{@link System#err}.
* @param ignoreExceptions If {@code "true"} (default) exceptions encountered when appending events are logged; otherwise they
* are propagated to the caller.
* @return The ConsoleAppender.
* @deprecated Deprecated in 2.7; use {@link #newBuilder()}.
*/
@Deprecated
public static ConsoleAppender createAppender(
// @formatter:off
Layout layout,
final Filter filter,
Target target,
final String name,
final boolean follow,
final boolean direct,
final boolean ignoreExceptions) {
// @formatter:on
if (name == null) {
LOGGER.error("No name provided for ConsoleAppender");
return null;
}
if (layout == null) {
layout = PatternLayout.createDefaultLayout();
}
target = target == null ? Target.SYSTEM_OUT : target;
if (follow && direct) {
LOGGER.error("Cannot use both follow and direct on ConsoleAppender");
return null;
}
return new ConsoleAppender(name, layout, filter, getManager(target, follow, direct, layout), ignoreExceptions, target, null);
}
public static ConsoleAppender createDefaultAppenderForLayout(final Layout layout) {
// this method cannot use the builder class without introducing an infinite loop due to DefaultConfiguration
return new ConsoleAppender("DefaultConsole-" + COUNT.incrementAndGet(), layout, null,
getDefaultManager(DEFAULT_TARGET, false, false, layout), true, DEFAULT_TARGET, null);
}
@PluginBuilderFactory
public static > B newBuilder() {
return new Builder().asBuilder();
}
/**
* Builds ConsoleAppender instances.
* @param The type to build
*/
public static class Builder> extends AbstractOutputStreamAppender.Builder
implements org.apache.logging.log4j.core.util.Builder {
@PluginBuilderAttribute
@Required
private Target target = DEFAULT_TARGET;
@PluginBuilderAttribute
private boolean follow;
@PluginBuilderAttribute
private boolean direct;
public B setTarget(final Target aTarget) {
this.target = aTarget;
return asBuilder();
}
public B setFollow(final boolean shouldFollow) {
this.follow = shouldFollow;
return asBuilder();
}
public B setDirect(final boolean shouldDirect) {
this.direct = shouldDirect;
return asBuilder();
}
@Override
public ConsoleAppender build() {
if (follow && direct) {
throw new IllegalArgumentException("Cannot use both follow and direct on ConsoleAppender '" + getName() + "'");
}
final Layout layout = getOrCreateLayout(target.getDefaultCharset());
return new ConsoleAppender(getName(), layout, getFilter(), getManager(target, follow, direct, layout),
isIgnoreExceptions(), target, getPropertyArray());
}
}
private static OutputStreamManager getDefaultManager(final Target target, final boolean follow, final boolean direct,
final Layout layout) {
final OutputStream os = getOutputStream(follow, direct, target);
// LOG4J2-1176 DefaultConfiguration should not share OutputStreamManager instances to avoid memory leaks.
final String managerName = target.name() + '.' + follow + '.' + direct + "-" + COUNT.get();
return OutputStreamManager.getManager(managerName, new FactoryData(os, managerName, layout), factory);
}
private static OutputStreamManager getManager(final Target target, final boolean follow, final boolean direct,
final Layout layout) {
final OutputStream os = getOutputStream(follow, direct, target);
final String managerName = target.name() + '.' + follow + '.' + direct;
return OutputStreamManager.getManager(managerName, new FactoryData(os, managerName, layout), factory);
}
private static OutputStream getOutputStream(final boolean follow, final boolean direct, final Target target) {
final String enc = Charset.defaultCharset().name();
OutputStream outputStream;
try {
// @formatter:off
outputStream = target == Target.SYSTEM_OUT ?
direct ? new FileOutputStream(FileDescriptor.out) :
(follow ? new PrintStream(new SystemOutStream(), true, enc) : System.out) :
direct ? new FileOutputStream(FileDescriptor.err) :
(follow ? new PrintStream(new SystemErrStream(), true, enc) : System.err);
// @formatter:on
outputStream = new CloseShieldOutputStream(outputStream);
} catch (final UnsupportedEncodingException ex) { // should never happen
throw new IllegalStateException("Unsupported default encoding " + enc, ex);
}
final PropertiesUtil propsUtil = PropertiesUtil.getProperties();
if (!propsUtil.isOsWindows() || propsUtil.getBooleanProperty("log4j.skipJansi", true) || direct) {
return outputStream;
}
try {
// We type the parameter as a wildcard to avoid a hard reference to Jansi.
final Class clazz = Loader.loadClass(JANSI_CLASS);
final Constructor constructor = clazz.getConstructor(OutputStream.class);
return new CloseShieldOutputStream((OutputStream) constructor.newInstance(outputStream));
} catch (final ClassNotFoundException cnfe) {
LOGGER.debug("Jansi is not installed, cannot find {}", JANSI_CLASS);
} catch (final NoSuchMethodException nsme) {
LOGGER.warn("{} is missing the proper constructor", JANSI_CLASS);
} catch (final Exception ex) {
LOGGER.warn("Unable to instantiate {} due to {}", JANSI_CLASS, clean(Throwables.getRootCause(ex).toString()).trim());
}
return outputStream;
}
private static String clean(final String string) {
return string.replace(Chars.NUL, Chars.SPACE);
}
/**
* An implementation of OutputStream that redirects to the current System.err.
*/
private static class SystemErrStream extends OutputStream {
public SystemErrStream() {
}
@Override
public void close() {
// do not close sys err!
}
@Override
public void flush() {
System.err.flush();
}
@Override
public void write(final byte[] b) throws IOException {
System.err.write(b);
}
@Override
public void write(final byte[] b, final int off, final int len) throws IOException {
System.err.write(b, off, len);
}
@Override
public void write(final int b) {
System.err.write(b);
}
}
/**
* An implementation of OutputStream that redirects to the current System.out.
*/
private static class SystemOutStream extends OutputStream {
public SystemOutStream() {
}
@Override
public void close() {
// do not close sys out!
}
@Override
public void flush() {
System.out.flush();
}
@Override
public void write(final byte[] b) throws IOException {
System.out.write(b);
}
@Override
public void write(final byte[] b, final int off, final int len) throws IOException {
System.out.write(b, off, len);
}
@Override
public void write(final int b) throws IOException {
System.out.write(b);
}
}
/**
* Data to pass to factory method.Unable to instantiate
*/
private static class FactoryData {
private final OutputStream os;
private final String name;
private final Layout layout;
/**
* Constructor.
*
* @param os The OutputStream.
* @param type The name of the target.
* @param layout A Serializable layout
*/
public FactoryData(final OutputStream os, final String type, final Layout layout) {
this.os = os;
this.name = type;
this.layout = layout;
}
}
/**
* Factory to create the Appender.
*/
private static class ConsoleManagerFactory implements ManagerFactory {
/**
* Create an OutputStreamManager.
*
* @param name The name of the entity to manage.
* @param data The data required to create the entity.
* @return The OutputStreamManager
*/
@Override
public OutputStreamManager createManager(final String name, final FactoryData data) {
return new OutputStreamManager(data.os, data.name, data.layout, true);
}
}
public Target getTarget() {
return target;
}
}