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/*
* de.unkrig.commons - A general-purpose Java class library
*
* Copyright (c) 2013, Arno Unkrig
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
* following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package de.unkrig.commons.util.logging.formatter;
import java.util.logging.Formatter;
import java.util.logging.Level;
import java.util.logging.LogRecord;
import java.util.logging.Logger;
import de.unkrig.commons.lang.protocol.Predicate;
import de.unkrig.commons.nullanalysis.NotNullByDefault;
import de.unkrig.commons.nullanalysis.Nullable;
/**
* A {@link Formatter} calls one of two delegates, depending on the evaluation result of a {@link LogRecord} {@link
* Predicate}.
*/
@NotNullByDefault(false) public
class SelectiveFormatter extends Formatter {
private final Predicate predicate;
private final Formatter delegate1, delegate2;
/**
* @param delegate1 Is called for {@link LogRecord} for which the {@code predicate} evaluates to {@code true}
* @param delegate2 Is called for {@link LogRecord} for which the {@code predicate} evaluates to {@code false}
*/
public
SelectiveFormatter(Predicate predicate, Formatter delegate1, Formatter delegate2) {
this.predicate = predicate;
this.delegate1 = delegate1;
this.delegate2 = delegate2;
}
/**
* Calls {@code delegate1} if the {@code predicate} evaluates to {@code true} for the {@code logRecord},
* otherwise {@code delegate2}.
*
* @see #SelectiveFormatter(Predicate, Formatter, Formatter)
*/
@Override public String
format(LogRecord logRecord) {
return (
this.predicate.evaluate(logRecord)
? this.delegate1.format(logRecord)
: this.delegate2.format(logRecord)
);
}
/**
* Returns a {@link Formatter} that for each {@link LogRecord} invokes {@code delegate1} if the level of the
* processing {@link Logger} is greater than {@code threshold}, and for all other the {@code delegate2}.
*
* A typical application is to format log records WITHOUT stack traces, except if the logger's level is set to
* {@link Level#FINE} or lower.
*/
public static final Formatter
loggerLevelGreaterThan(final Level threshold, Formatter delegate1, Formatter delegate2) {
return new SelectiveFormatter(new Predicate() {
@Override public boolean
evaluate(@Nullable LogRecord logRecord) {
// Getting the logger by name is not exactly superfast, but, hey, we're here for FORMATTING, which
// is the second-but-last step in the logging chain, so the performance hit should be small.
// Why the heck does the log record keep the logger NAME, and not a REFERENCE TO THE LOGGER? Is see
// no good reasons for this choice. Bummer.
return logRecord != null && !Logger.getLogger(logRecord.getLoggerName()).isLoggable(threshold);
}
}, delegate1, delegate2);
}
/**
* Returns a {@link Formatter} that for each {@link LogRecord} invokes {@code delegate1} if the level of the log
* record is greater than ("more severe than") {@code threshold}, and for all other the {@code delegate2}.
*
* A typical application is to format log records WITHOUT stack traces, except if the logger's level is set to
* {@link Level#FINE} or lower.
*/
public static final Formatter
logRecordLevelGreaterThan(final Level threshold, Formatter delegate1, Formatter delegate2) {
return new SelectiveFormatter(new Predicate() {
@Override public boolean
evaluate(@Nullable LogRecord logRecord) {
return logRecord != null && logRecord.getLevel().intValue() > threshold.intValue();
}
}, delegate1, delegate2);
}
}