nl.basjes.parse.httpdlog.dissectors.StrfTimeToDateTimeFormatter Maven / Gradle / Ivy
/*
* Apache HTTPD & NGINX Access log parsing made easy
* Copyright (C) 2011-2018 Niels Basjes
*
* Licensed 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 nl.basjes.parse.httpdlog.dissectors;
import nl.basjes.parse.strftime.StrfTimeBaseListener;
import nl.basjes.parse.strftime.StrfTimeLexer;
import nl.basjes.parse.strftime.StrfTimeParser;
import org.antlr.v4.runtime.ANTLRErrorListener;
import org.antlr.v4.runtime.CharStreams;
import org.antlr.v4.runtime.CodePointCharStream;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.atn.ATNConfigSet;
import org.antlr.v4.runtime.dfa.DFA;
import org.antlr.v4.runtime.tree.ParseTreeWalker;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.time.format.SignStyle;
import java.time.format.TextStyle;
import java.time.temporal.ChronoField;
import java.time.temporal.WeekFields;
import java.util.BitSet;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
public final class StrfTimeToDateTimeFormatter extends StrfTimeBaseListener implements ANTLRErrorListener {
private static final Logger LOG = LoggerFactory.getLogger(StrfTimeToDateTimeFormatter.class);
private static final WeekFields LOCAL_WEEK_FIELDS = WeekFields.of(Locale.getDefault());
public static DateTimeFormatter convert(String strfformat) {
return convert(strfformat, ZoneOffset.UTC);
}
public static DateTimeFormatter convert(String strfformat, ZoneId defaultZone) {
CodePointCharStream input = CharStreams.fromString(strfformat);
StrfTimeLexer lexer = new StrfTimeLexer(input);
CommonTokenStream tokens = new CommonTokenStream(lexer);
StrfTimeParser parser = new StrfTimeParser(tokens);
lexer.removeErrorListeners();
parser.removeErrorListeners();
ParseTreeWalker walker = new ParseTreeWalker(); // create standard walker
StrfTimeToDateTimeFormatter converter = new StrfTimeToDateTimeFormatter(strfformat, defaultZone);
lexer.addErrorListener(converter);
parser.addErrorListener(converter);
StrfTimeParser.PatternContext pattern = parser.pattern();
walker.walk(converter, pattern); // initiate walk of tree with listener
if (converter.hasSyntaxError()) {
return null;
}
return converter.build();
}
private String strfformat;
private DateTimeFormatterBuilder builder;
private ZoneId defaultZone;
private boolean zoneWasSpecified = false;
private StrfTimeToDateTimeFormatter(String inputStrfformat, ZoneId newDefaultZone) {
strfformat = inputStrfformat;
defaultZone = newDefaultZone;
builder = new DateTimeFormatterBuilder()
.parseCaseInsensitive();
}
public DateTimeFormatter build() {
DateTimeFormatter dateTimeFormatter = builder.toFormatter();
if (!zoneWasSpecified) {
dateTimeFormatter = dateTimeFormatter.withZone(defaultZone);
LOG.warn("The timestamp format \"{}\" does NOT contain a timezone so we assume \"{}\".",
strfformat, defaultZone.getDisplayName(TextStyle.SHORT, Locale.ENGLISH));
}
return dateTimeFormatter;
}
// ------------- Error handling --------------
private boolean syntaxError = false;
public boolean hasSyntaxError() {
return syntaxError;
}
@Override
public void syntaxError(Recognizer recognizer, Object o, int i, int i1, String s, RecognitionException e) {
syntaxError = true;
}
@Override
public void reportAmbiguity(org.antlr.v4.runtime.Parser parser, DFA dfa, int i, int i1, boolean b, BitSet bitSet, ATNConfigSet atnConfigSet) {
}
@Override
public void reportAttemptingFullContext(org.antlr.v4.runtime.Parser parser, DFA dfa, int i, int i1, BitSet bitSet, ATNConfigSet atnConfigSet) {
}
@Override
public void reportContextSensitivity(org.antlr.v4.runtime.Parser parser, DFA dfa, int i, int i1, int i2, ATNConfigSet atnConfigSet) {
}
public static class UnsupportedStrfField extends RuntimeException {
public UnsupportedStrfField(String s) {
super("The field '" + s + "' cannot be converted towards a DateTimeFormatter field.");
}
}
// ------------- Mapping --------------
@Override
public void enterMsecFrac(StrfTimeParser.MsecFracContext ctx) {
// Apache HTTPD specific: milliseconds fraction
builder.appendValue(ChronoField.MILLI_OF_SECOND, 3);
}
@Override
public void enterUsecFrac(StrfTimeParser.UsecFracContext ctx) {
// Apache HTTPD specific: microseconds fraction
builder.appendValue(ChronoField.MICRO_OF_SECOND, 6);
}
@Override
public void enterText(StrfTimeParser.TextContext ctx) {
builder.appendLiteral(ctx.getText());
}
@Override
public void enterTab(StrfTimeParser.TabContext ctx) {
builder.appendLiteral('\t');
}
@Override
public void enterPercent(StrfTimeParser.PercentContext ctx) {
builder.appendLiteral('%');
}
@Override
public void enterNewline(StrfTimeParser.NewlineContext ctx) {
builder.appendLiteral('\n');
}
@Override
public void enterPa(StrfTimeParser.PaContext ctx) {
// %a The abbreviated name of the day of the week according to the current locale.
builder.appendText(ChronoField.DAY_OF_WEEK, TextStyle.SHORT);
}
@Override
public void enterPA(StrfTimeParser.PAContext ctx) {
// %A The full name of the day of the week according to the current locale.
builder.appendText(ChronoField.DAY_OF_WEEK, TextStyle.FULL);
}
@Override
public void enterPb(StrfTimeParser.PbContext ctx) {
// %b The abbreviated month name according to the current locale.
// %h Equivalent to %b.
builder.appendText(ChronoField.MONTH_OF_YEAR, TextStyle.SHORT);
}
@Override
public void enterPB(StrfTimeParser.PBContext ctx) {
// %B The full month name according to the current locale.
builder.appendText(ChronoField.MONTH_OF_YEAR, TextStyle.FULL);
}
@Override
public void enterPc(StrfTimeParser.PcContext ctx) {
// %c The preferred date and time representation for the current locale.
throw new UnsupportedStrfField("%c The preferred date and time representation for the current locale.");
}
@Override
public void enterPC(StrfTimeParser.PCContext ctx) {
throw new UnsupportedStrfField("%C The century number (year/100) as a 2-digit integer.");
}
@Override
public void enterPd(StrfTimeParser.PdContext ctx) {
// %d The day of the month as a decimal number (range 01 to 31).
builder.appendValue(ChronoField.DAY_OF_MONTH, 2);
}
@Override
public void enterPD(StrfTimeParser.PDContext ctx) {
// %D Equivalent to %m/%d/%y. (Yecch—for Americans only)
builder
.appendValue(ChronoField.MONTH_OF_YEAR, 2)
.appendLiteral('/')
.appendValue(ChronoField.DAY_OF_MONTH, 2)
.appendLiteral('/')
.appendValueReduced(ChronoField.YEAR, 2, 2, 2000);
}
@Override
public void enterPe(StrfTimeParser.PeContext ctx) {
// %e Like %d, the day of the month as a decimal number, but a leading zero is replaced by a space.
builder.padNext(2, ' ').appendValue(ChronoField.DAY_OF_MONTH);
}
@Override
public void enterPF(StrfTimeParser.PFContext ctx) {
// %F Equivalent to %Y-%m-%d (the ISO 8601 date format).
builder
.appendValue(ChronoField.YEAR, 4)
.appendLiteral('-')
.appendValue(ChronoField.MONTH_OF_YEAR, 2)
.appendLiteral('-')
.appendValue(ChronoField.DAY_OF_MONTH, 2);
}
@Override
public void enterPG(StrfTimeParser.PGContext ctx) {
// %G The ISO 8601 week-based year (see NOTES) with century as a decimal number.
// The 4-digit year corresponding to the ISO week number (see %V).
// This has the same format and value as %Y, except that if the ISO week number
// belongs to the previous or next year, that year is used instead.
builder.appendValue(LOCAL_WEEK_FIELDS.weekBasedYear(), 4);
}
@Override
public void enterPg(StrfTimeParser.PgContext ctx) {
// %g Like %G, but without century, that is, with a 2-digit year (00–99).
builder.appendValueReduced(LOCAL_WEEK_FIELDS.weekBasedYear(), 2, 2, 2000);
}
@Override
public void enterPH(StrfTimeParser.PHContext ctx) {
// %H The hour as a decimal number using a 24-hour clock (range 00 to 23).
builder.appendValue(ChronoField.CLOCK_HOUR_OF_DAY, 2);
}
@Override
public void enterPI(StrfTimeParser.PIContext ctx) {
// %I The hour as a decimal number using a 12-hour clock (range 01 to 12).
builder.appendValue(ChronoField.CLOCK_HOUR_OF_AMPM, 2);
}
@Override
public void enterPj(StrfTimeParser.PjContext ctx) {
// %j The day of the year as a decimal number (range 001 to 366).
builder.appendValue(ChronoField.DAY_OF_YEAR, 3);
}
@Override
public void enterPk(StrfTimeParser.PkContext ctx) {
// %k The hour (24-hour clock) as a decimal number (range 0 to 23); single digits are preceded by a blank.
// (See also %H)
builder.padNext(2, ' ').appendValue(ChronoField.CLOCK_HOUR_OF_DAY);
}
@Override
public void enterPl(StrfTimeParser.PlContext ctx) {
// %l The hour (12-hour clock) as a decimal number (range 1 to 12); single digits are preceded by a blank.
// (See also %I)
builder.padNext(2, ' ').appendValue(ChronoField.CLOCK_HOUR_OF_AMPM);
}
@Override
public void enterPm(StrfTimeParser.PmContext ctx) {
// %m The month as a decimal number (range 01 to 12).
builder.appendValue(ChronoField.MONTH_OF_YEAR, 2);
}
@Override
public void enterPM(StrfTimeParser.PMContext ctx) {
// %M The minute as a decimal number (range 00 to 59).
builder.appendValue(ChronoField.MINUTE_OF_HOUR, 2);
}
@Override
public void enterPp(StrfTimeParser.PpContext ctx) {
// %p Either "AM" or "PM" according to the given time value, or the corresponding strings for the current locale.
// Noon is treated as "PM" and midnight as "AM".
builder.appendText(ChronoField.AMPM_OF_DAY, TextStyle.SHORT);
}
private static final Map AMPM_LOWER_CASE_MAPPING = new HashMap<>();
static {
AMPM_LOWER_CASE_MAPPING.put(0L, "am");
AMPM_LOWER_CASE_MAPPING.put(1L, "pm");
}
@Override
public void enterPP(StrfTimeParser.PPContext ctx) {
// %P Like %p but in lowercase: "am" or "pm" or a corresponding string for the current locale.
builder.appendText(ChronoField.AMPM_OF_DAY, AMPM_LOWER_CASE_MAPPING);
}
@Override
public void enterPr(StrfTimeParser.PrContext ctx) {
// %r The time in a.m. or p.m. notation. In the POSIX locale this is equivalent to %I:%M:%S %p.
builder
.appendValue(ChronoField.CLOCK_HOUR_OF_AMPM, 2)
.appendLiteral(':')
.appendValue(ChronoField.MINUTE_OF_HOUR, 2)
.appendLiteral(':')
.appendValue(ChronoField.SECOND_OF_MINUTE, 2)
.appendLiteral(' ')
.appendText(ChronoField.AMPM_OF_DAY, TextStyle.SHORT);
}
@Override
public void enterPR(StrfTimeParser.PRContext ctx) {
// %R The time in 24-hour notation (%H:%M). For a version including the seconds, see %T below.
builder
.appendValue(ChronoField.HOUR_OF_DAY, 2)
.appendLiteral(':')
.appendValue(ChronoField.MINUTE_OF_HOUR, 2);
}
@Override
public void enterPs(StrfTimeParser.PsContext ctx) {
// %s The number of seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC).
// Based upon https://stackoverflow.com/questions/36066155/datetimeformatter-for-epoch-milliseconds#answer-36069732
builder
.appendValue(ChronoField.INSTANT_SECONDS, 1, 19, SignStyle.NEVER);
}
@Override
public void enterPS(StrfTimeParser.PSContext ctx) {
// %S The second as a decimal number (range 00 to 60). (The range is up to 60 to allow for occasional leap seconds)
builder
.appendValue(ChronoField.SECOND_OF_MINUTE, 2);
}
@Override
public void enterPT(StrfTimeParser.PTContext ctx) {
// %T The time in 24-hour notation (%H:%M:%S).
builder
.appendValue(ChronoField.HOUR_OF_DAY, 2)
.appendLiteral(':')
.appendValue(ChronoField.MINUTE_OF_HOUR, 2)
.appendLiteral(':')
.appendValue(ChronoField.SECOND_OF_MINUTE, 2);
}
@Override
public void enterPu(StrfTimeParser.PuContext ctx) {
// %u The day of the week as a decimal, range 1 to 7, Monday being 1. See also %w.
builder.appendValue(WeekFields.ISO.dayOfWeek(), 1);
}
@Override
public void enterPU(StrfTimeParser.PUContext ctx) {
// %U The week number of the current year as a decimal number, range 00 to 53, starting with
// the first Sunday as the first day of week 01. See also %V and %W.
throw new UnsupportedStrfField("%U The week number of the current year ... ");
}
@Override
public void enterPV(StrfTimeParser.PVContext ctx) {
// %V The ISO 8601 week number (see NOTES) of the current year as a decimal number, range 01 to 53,
// where week 1 is the first week that has at least 4 days in the new year. See also %U and %W.
builder.appendValue(WeekFields.ISO.weekOfYear());
}
@Override
public void enterPw(StrfTimeParser.PwContext ctx) {
// %w The day of the week as a decimal, range 0 to 6, Sunday being 0. See also %u.
throw new UnsupportedStrfField("%w The day of the week as a decimal, range 0 to 6, Sunday being 0. See also %u.");
}
@Override
public void enterPW(StrfTimeParser.PWContext ctx) {
// %W The week number of the current year as a decimal number, range 00 to 53,
// starting with the first Monday as the first day of week 01.
builder.appendValue(WeekFields.ISO.weekOfYear(), 2);
}
@Override
public void enterPx(StrfTimeParser.PxContext ctx) {
// %x The preferred date representation for the current locale without the time.
throw new UnsupportedStrfField("%x The preferred date representation for the current locale without the time.");
}
@Override
public void enterPX(StrfTimeParser.PXContext ctx) {
// %X The preferred time representation for the current locale without the date.
throw new UnsupportedStrfField("%X The preferred time representation for the current locale without the date.");
}
@Override
public void enterPy(StrfTimeParser.PyContext ctx) {
// %y The year as a decimal number without a century (range 00 to 99).
builder.appendValueReduced(ChronoField.YEAR, 2, 2, 2000);
}
@Override
public void enterPY(StrfTimeParser.PYContext ctx) {
// %Y The year as a decimal number including the century.
builder.appendValue(ChronoField.YEAR, 4);
}
@Override
public void enterPz(StrfTimeParser.PzContext ctx) {
// %z The +hhmm or -hhmm numeric timezone.
builder.appendOffset("+HHMM", "+0000");
zoneWasSpecified = true;
}
@Override
public void enterPZ(StrfTimeParser.PZContext ctx) {
// %Z The timezone name or abbreviation.
builder.appendZoneText(TextStyle.SHORT);
zoneWasSpecified = true;
}
@Override
public void enterPplus(StrfTimeParser.PplusContext ctx) {
throw new UnsupportedStrfField("%p The date and time in date(1) format.");
}
}
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