8222484: Specialize generation of simple String concatenation expressions
Reviewed-by: jrose, jlaskey
/*
* Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
/**
* This application is meant to be run to create a classlist file representing
* common use.
*
* The classlist is produced by adding -XX:DumpLoadedClassList=classlist
*/
package build.tools.classlist;
import java.net.InetAddress;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.stream.Stream;
import java.util.logging.*;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.text.DateFormat;
import static java.util.stream.Collectors.*;
/**
* This class is used to generate a classlist during build. Intent
* is to touch a reasonable amount of JDK classes that are commonly
* loaded and used early.
*/
public class HelloClasslist {
private static final Logger LOGGER = Logger.getLogger("Hello");
public static void main(String ... args) {
List<String> strings = Arrays.asList("Hello", "World!", "From: ",
InetAddress.getLoopbackAddress().toString());
String helloWorld = strings.parallelStream()
.map(s -> s.toLowerCase(Locale.ROOT))
.collect(joining(","));
Stream.of(helloWorld.split(","))
.forEach(System.out::println);
// Common concatenation patterns
String SS = String.valueOf(args.length) + String.valueOf(args.length);
String CS = "string" + String.valueOf(args.length);
String SC = String.valueOf(args.length) + "string";
String SCS = String.valueOf(args.length) + "string" + String.valueOf(args.length);
String CSS = "string" + String.valueOf(args.length) + String.valueOf(args.length);
String CSCS = "string" + String.valueOf(args.length) + "string" + String.valueOf(args.length);
String SCSC = String.valueOf(args.length) + "string" + String.valueOf(args.length) + "string";
String CSCSC = "string" + String.valueOf(args.length) + "string" + String.valueOf(args.length) + "string";
String SCSCS = String.valueOf(args.length) + "string" + String.valueOf(args.length) + "string" + String.valueOf(args.length);
String CI = "string" + args.length;
String IC = args.length + "string";
String CIC = "string" + args.length + "string";
String CICI = "string" + args.length + "string" + args.length;
String CJ = "string" + System.currentTimeMillis();
String JC = System.currentTimeMillis() + "string";
String CJC = "string" + System.currentTimeMillis() + "string";
String CJCJ = "string" + System.currentTimeMillis() + "string" + System.currentTimeMillis();
String CJCJC = "string" + System.currentTimeMillis() + "string" + System.currentTimeMillis() + "string";
String newDate = DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(
LocalDateTime.now(ZoneId.of("GMT")));
String oldDate = String.format("%s%n",
DateFormat.getDateInstance(DateFormat.DEFAULT, Locale.ROOT)
.format(new Date()));
LOGGER.log(Level.INFO, "New Date: " + newDate + " - old: " + oldDate);
}
}