org.slf4j.helpers.Reporter Maven / Gradle / Ivy
package org.slf4j.helpers;
import java.io.PrintStream;
/**
* An internally used class for reporting internal messages generated by SLF4J itself during initialization.
*
*
* Internal reporting is performed by calling the {@link #info(String)}, {@link #warn(String)} (String)}
* {@link #error(String)} (String)} and {@link #error(String, Throwable)} methods.
*
* See {@link #SLF4J_INTERNAL_VERBOSITY_KEY} and {@link #SLF4J_INTERNAL_REPORT_STREAM_KEY} for
* configuration options.
*
*
* Note that this system is independent of the logging back-end in use.
*
* @since 2.0.10
*/
public class Reporter {
/**
* this class is used internally by Reporter
*/
private enum Level {
INFO(1), WARN(2), ERROR(3);
int levelInt;
private Level(int levelInt) {
this.levelInt = levelInt;
}
private int getLevelInt() {
return levelInt;
}
}
private enum TargetChoice {
Stderr, Stdout;
}
static final String SLF4J_INFO_PREFIX = "SLF4J(I): ";
static final String SLF4J_WARN_PREFIX = "SLF4J(W): ";
static final String SLF4J_ERROR_PREFIX = "SLF4J(E): ";
/**
* This system property controls the target for internal reports output by SLF4J.
* Recognized values for this key are "System.out", "stdout", "sysout", "System.err",
* "stderr" and "syserr".
*
*
By default, output is directed to "stderr".
*/
public static final String SLF4J_INTERNAL_REPORT_STREAM_KEY = "slf4j.internal.report.stream";
static private final String[] SYSOUT_KEYS = {"System.out", "stdout", "sysout"};
/**
* This system property controls the internal level of chattiness
* of SLF4J. Recognized settings are "INFO", "WARN" and "ERROR". The default value is "INFO".
*/
public static final String SLF4J_INTERNAL_VERBOSITY_KEY = "slf4j.internal.verbosity";
static private final TargetChoice TARGET_CHOICE = initTargetChoice();
static private final Level INTERNAL_VERBOSITY = initVerbosity();
static private TargetChoice initTargetChoice() {
String reportStreamStr = System.getProperty(SLF4J_INTERNAL_REPORT_STREAM_KEY);
if(reportStreamStr == null || reportStreamStr.isEmpty()) {
return TargetChoice.Stderr;
}
for(String s : SYSOUT_KEYS) {
if(s.equalsIgnoreCase(reportStreamStr))
return TargetChoice.Stdout;
}
return TargetChoice.Stderr;
}
static private Level initVerbosity() {
String verbosityStr = System.getProperty(SLF4J_INTERNAL_VERBOSITY_KEY);
if(verbosityStr == null || verbosityStr.isEmpty()) {
return Level.INFO;
}
if(verbosityStr.equalsIgnoreCase("ERROR")) {
return Level.ERROR;
}
if(verbosityStr.equalsIgnoreCase("WARN")) {
return Level.WARN;
}
return Level.INFO;
}
static boolean isEnabledFor(Level level) {
return (level.levelInt >= INTERNAL_VERBOSITY.levelInt);
}
static private PrintStream getTarget() {
switch(TARGET_CHOICE) {
case Stdout:
return System.out;
case Stderr:
default:
return System.err;
}
}
/**
* Report an internal message of level INFO. Message text is prefixed with the string "SLF4J(I)", with
* (I) standing as a shorthand for INFO.
*
* Messages of level INFO are be enabled when the {@link #SLF4J_INTERNAL_VERBOSITY_KEY} system property is
* set to "INFO" and disabled when set to "WARN" or "ERROR". By default, {@link #SLF4J_INTERNAL_VERBOSITY_KEY} is
* set to "INFO".
*
* @param msg the message text
*/
public static void info(String msg) {
if(isEnabledFor(Level.INFO)) {
getTarget().println(SLF4J_INFO_PREFIX + msg);
}
}
/**
* Report an internal message of level "WARN". Message text is prefixed with the string "SLF4J(W)", with
* (W) standing as a shorthand for WARN.
*
* Messages of level WARN are be enabled when the {@link #SLF4J_INTERNAL_VERBOSITY_KEY} system property is
* set to "INFO" or "WARN" and disabled when set to "ERROR". By default, {@link #SLF4J_INTERNAL_VERBOSITY_KEY} is
* set to "INFO".
*
* @param msg the message text
*/
static final public void warn(String msg) {
if(isEnabledFor(Level.WARN)) {
getTarget().println(SLF4J_WARN_PREFIX + msg);
}
}
/**
* Report an internal message of level "ERROR accompanied by a {@link Throwable}.
* Message text is prefixed with the string "SLF4J(E)", with (E) standing as a shorthand for ERROR.
*
* Messages of level ERROR are always enabled.
*
* @param msg the message text
* @param t a Throwable
*/
static final public void error(String msg, Throwable t) {
// error cannot be disabled
getTarget().println(SLF4J_ERROR_PREFIX + msg);
getTarget().println(SLF4J_ERROR_PREFIX + "Reported exception:");
t.printStackTrace(getTarget());
}
/**
* Report an internal message of level "ERROR". Message text is prefixed with the string "SLF4J(E)", with
* (E) standing as a shorthand for ERROR.
*
*
Messages of level ERROR are always enabled.
*
* @param msg the message text
*/
static final public void error(String msg) {
// error cannot be disabled
getTarget().println(SLF4J_ERROR_PREFIX + msg);
}
}