ch.qos.logback.core.ConsoleAppender Maven / Gradle / Ivy
/**
* Logback: the reliable, generic, fast and flexible logging framework.
* Copyright (C) 1999-2015, QOS.ch. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation.
*/
package ch.qos.logback.core;
import java.io.OutputStream;
import java.io.PrintStream;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.NoSuchElementException;
import java.util.Optional;
import ch.qos.logback.core.joran.spi.ConsoleTarget;
import ch.qos.logback.core.status.Status;
import ch.qos.logback.core.status.WarnStatus;
import ch.qos.logback.core.util.Loader;
/**
* ConsoleAppender appends log events to System.out or
* System.err using a layout specified by the user. The default
* target is System.out.
*
*
*
* For more information about this appender, please refer to the online manual
* at http://logback.qos.ch/manual/appenders.html#ConsoleAppender
*
* @author Ceki Gülcü
* @author Tom SH Liu
* @author Ruediger Dohna
*/
public class ConsoleAppender extends OutputStreamAppender {
protected ConsoleTarget target = ConsoleTarget.SystemOut;
protected boolean withJansi = false;
private final static String AnsiConsole_CLASS_NAME = "org.fusesource.jansi.AnsiConsole";
private final static String JANSI2_OUT_METHOD_NAME = "out";
private final static String JANSI2_ERR_METHOD_NAME = "err";
private final static String wrapSystemOut_METHOD_NAME = "wrapSystemOut";
private final static String wrapSystemErr_METHOD_NAME = "wrapSystemErr";
private final static Class[] ARGUMENT_TYPES = { PrintStream.class };
/**
* Sets the value of the Target option. Recognized values are
* "System.out" and "System.err". Any other value will be ignored.
*/
public void setTarget(String value) {
ConsoleTarget t = ConsoleTarget.findByName(value.trim());
if (t == null) {
targetWarn(value);
} else {
target = t;
}
}
/**
* Returns the current value of the target property. The default value of
* the option is "System.out".
*
* See also {@link #setTarget}.
*/
public String getTarget() {
return target.getName();
}
private void targetWarn(String val) {
Status status = new WarnStatus("[" + val + "] should be one of " + Arrays.toString(ConsoleTarget.values()),
this);
status.add(new WarnStatus("Using previously set target, System.out by default.", this));
addStatus(status);
}
@Override
public void start() {
OutputStream targetStream = target.getStream();
// enable jansi only if withJansi set to true
if (withJansi) {
targetStream = wrapWithJansi(targetStream);
}
setOutputStream(targetStream);
super.start();
}
private OutputStream wrapWithJansi(OutputStream targetStream) {
try {
addInfo("Enabling JANSI AnsiPrintStream for the console.");
ClassLoader classLoader = Loader.getClassLoaderOfObject(context);
Class classObj = classLoader.loadClass(AnsiConsole_CLASS_NAME);
// check for JAnsi 2
String methodNameJansi2 = target == ConsoleTarget.SystemOut ? JANSI2_OUT_METHOD_NAME
: JANSI2_ERR_METHOD_NAME;
final Optional optOutMethod = Arrays.stream(classObj.getMethods())
.filter(m -> m.getName().equals(methodNameJansi2))
.filter(m -> m.getParameters().length == 0)
.filter(m -> Modifier.isStatic(m.getModifiers()))
.filter(m -> PrintStream.class.isAssignableFrom(m.getReturnType()))
.findAny();
if (optOutMethod.isPresent()) {
final Method outMethod = optOutMethod.orElseThrow(() -> new NoSuchElementException("No value present"));
return (PrintStream) outMethod.invoke(null);
}
// JAnsi 1
String methodName = target == ConsoleTarget.SystemOut ? wrapSystemOut_METHOD_NAME
: wrapSystemErr_METHOD_NAME;
Method method = classObj.getMethod(methodName, ARGUMENT_TYPES);
return (OutputStream) method.invoke(null, new PrintStream(targetStream));
} catch (Exception e) {
addWarn("Failed to create AnsiPrintStream. Falling back on the default stream.", e);
}
return targetStream;
}
/**
* @return whether to use JANSI or not.
*/
public boolean isWithJansi() {
return withJansi;
}
/**
* If true, this appender will output to a stream provided by the JANSI library.
*
* @param withJansi whether to use JANSI or not.
* @since 1.0.5
*/
public void setWithJansi(boolean withJansi) {
this.withJansi = withJansi;
}
}