/*
* 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 java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Constructor;
import java.nio.charset.Charset;
import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginElement;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.helpers.Booleans;
import org.apache.logging.log4j.core.helpers.Loader;
import org.apache.logging.log4j.core.layout.PatternLayout;
import org.apache.logging.log4j.util.PropertiesUtil;
/**
* ConsoleAppender appends log events to <code>System.out</code> or
* <code>System.err</code> using a layout specified by the user. The
* default target is <code>System.out</code>.
* @doubt accessing System.out or .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 = "Console", category = "Core", elementType = "appender", printObject = true)
public final class ConsoleAppender extends AbstractOutputStreamAppender {
private static final String JANSI_CLASS = "org.fusesource.jansi.WindowsAnsiOutputStream";
private static ConsoleManagerFactory factory = new ConsoleManagerFactory();
/**
* Enumeration of console destinations.
*/
public enum Target {
/** Standard output. */
SYSTEM_OUT,
/** Standard error output. */
SYSTEM_ERR
}
private ConsoleAppender(final String name, final Layout<? extends Serializable> layout, final Filter filter,
final OutputStreamManager manager,
final boolean ignoreExceptions) {
super(name, layout, filter, ignoreExceptions, true, manager);
}
/**
* Create a Console Appender.
* @param layout The layout to use (required).
* @param filter The Filter or null.
* @param t The target ("SYSTEM_OUT" or "SYSTEM_ERR"). The default is "SYSTEM_OUT".
* @param follow If true will follow changes to the underlying output stream.
* @param name The name of the Appender (required).
* @param ignore If {@code "true"} (default) exceptions encountered when appending events are logged; otherwise
* they are propagated to the caller.
* @return The ConsoleAppender.
*/
@PluginFactory
public static ConsoleAppender createAppender(
@PluginElement("Layout") Layout<? extends Serializable> layout,
@PluginElement("Filters") final Filter filter,
@PluginAttribute("target") final String t,
@PluginAttribute("name") final String name,
@PluginAttribute("follow") final String follow,
@PluginAttribute("ignoreExceptions") final String ignore) {
if (name == null) {
LOGGER.error("No name provided for ConsoleAppender");
return null;
}
if (layout == null) {
layout = PatternLayout.createLayout(null, null, null, null, null);
}
final boolean isFollow = Boolean.parseBoolean(follow);
final boolean ignoreExceptions = Booleans.parseBoolean(ignore, true);
final Target target = t == null ? Target.SYSTEM_OUT : Target.valueOf(t);
return new ConsoleAppender(name, layout, filter, getManager(isFollow, target, layout), ignoreExceptions);
}
private static OutputStreamManager getManager(final boolean follow, final Target target, final Layout<? extends Serializable> layout) {
final String type = target.name();
final OutputStream os = getOutputStream(follow, target);
return OutputStreamManager.getManager(target.name() + "." + follow, new FactoryData(os, type, layout), factory);
}
private static OutputStream getOutputStream(final boolean follow, final Target target) {
final String enc = Charset.defaultCharset().name();
PrintStream printStream = null;
try {
printStream = target == Target.SYSTEM_OUT ?
follow ? new PrintStream(new SystemOutStream(), true, enc) : System.out :
follow ? new PrintStream(new SystemErrStream(), true, enc) : System.err;
} catch (final UnsupportedEncodingException ex) { // should never happen
throw new IllegalStateException("Unsupported default encoding " + enc, ex);
}
final PropertiesUtil propsUtil = PropertiesUtil.getProperties();
if (!propsUtil.getStringProperty("os.name").startsWith("Windows") ||
propsUtil.getBooleanProperty("log4j.skipJansi")) {
return printStream;
}
try {
final ClassLoader loader = Loader.getClassLoader();
// 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 (OutputStream) constructor.newInstance(printStream);
} 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 Throwable ex) { // CraftBukkit - Exception -> Throwable
LOGGER.warn("Unable to instantiate {}", JANSI_CLASS);
}
return printStream;
}
/**
* 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.
*/
private static class FactoryData {
private final OutputStream os;
private final String type;
private final Layout<? extends Serializable> 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<? extends Serializable> layout) {
this.os = os;
this.type = type;
this.layout = layout;
}
}
/**
* Factory to create the Appender.
*/
private static class ConsoleManagerFactory implements ManagerFactory<OutputStreamManager, FactoryData> {
/**
* 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.type, data.layout);
}
}
}