├── .gitignore ├── .mvn └── wrapper │ ├── maven-wrapper.jar │ └── maven-wrapper.properties ├── README.md ├── images ├── embracing-virtual-threads.png ├── java-is-made-of-threads.png ├── scalability-solutions.png ├── spring-init.png ├── thread-per-request.png └── virtual-threads.png ├── mvnw ├── mvnw.cmd ├── pom.xml └── src └── main ├── java └── com │ └── devnexus │ └── loom │ ├── Application.java │ └── HomeController.java └── resources └── application.properties /.gitignore: -------------------------------------------------------------------------------- 1 | HELP.md 2 | target/ 3 | !.mvn/wrapper/maven-wrapper.jar 4 | !**/src/main/**/target/ 5 | !**/src/test/**/target/ 6 | 7 | ### STS ### 8 | .apt_generated 9 | .classpath 10 | .factorypath 11 | .project 12 | .settings 13 | .springBeans 14 | .sts4-cache 15 | 16 | ### IntelliJ IDEA ### 17 | .idea 18 | *.iws 19 | *.iml 20 | *.ipr 21 | 22 | ### NetBeans ### 23 | /nbproject/private/ 24 | /nbbuild/ 25 | /dist/ 26 | /nbdist/ 27 | /.nb-gradle/ 28 | build/ 29 | !**/src/main/**/build/ 30 | !**/src/test/**/build/ 31 | 32 | ### VS Code ### 33 | .vscode/ 34 | -------------------------------------------------------------------------------- /.mvn/wrapper/maven-wrapper.jar: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/danvega/loom/ea1d482d08c9564aae128ac193247545ff5664de/.mvn/wrapper/maven-wrapper.jar -------------------------------------------------------------------------------- /.mvn/wrapper/maven-wrapper.properties: -------------------------------------------------------------------------------- 1 | # Licensed to the Apache Software Foundation (ASF) under one 2 | # or more contributor license agreements. See the NOTICE file 3 | # distributed with this work for additional information 4 | # regarding copyright ownership. The ASF licenses this file 5 | # to you under the Apache License, Version 2.0 (the 6 | # "License"); you may not use this file except in compliance 7 | # with the License. You may obtain a copy of the License at 8 | # 9 | # https://www.apache.org/licenses/LICENSE-2.0 10 | # 11 | # Unless required by applicable law or agreed to in writing, 12 | # software distributed under the License is distributed on an 13 | # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 14 | # KIND, either express or implied. See the License for the 15 | # specific language governing permissions and limitations 16 | # under the License. 17 | distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.7/apache-maven-3.8.7-bin.zip 18 | wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.1/maven-wrapper-3.1.1.jar 19 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Spring Boot + Project Loom 2 | 3 | In this project you will learn about how threads currently work in Java and what problems Project Loom intends to solve. First we will start with a refresher on how threads work and then a quick demo of how to use Virtual Threads in Spring. 4 | 5 | ## Embracing Virtual Threads 6 | 7 | Project Loom aims to reduce the effort of writing, maintaining and observing high-throughput thread-based applications. In the following example we have a typical Spring MVC application that performs blocking operations like connecting to a database, writing a file to disk, making a network call to another service or working with a message broker. 8 | 9 | ![Embracing Virtual Threads](./images/embracing-virtual-threads.png) 10 | 11 | When these types of applications experience higher throughput than they are able to handle they will end up crashing. Why is this happening? What can you do to prevent this from happening? 12 | 13 | ## Thread Per Request Model 14 | 15 | The thread-per-request model is a common pattern in web applications. It is a simple model where each request is handled by a separate thread. This model is easy to understand and implement. However, it has some drawbacks. When a thread has perform a blocking operation like connecting to a database or making a network call it will be blocked until the operation is complete. This means that the thread will not be able to handle any other requests. 16 | 17 | ![Thread Per Request Model](./images/thread-per-request.png) 18 | 19 | ## Java is made of Threads 20 | 21 | A thread in Java is tied to an Operating System thread. This means that each thread in Java will consume a thread in the Operating System. This is a problem because the Operating System has a limit on the number of threads it can handle. 22 | 23 | ![Java is made of Threads](./images/java-is-made-of-threads.png) 24 | 25 | ## Scalability Solutions 26 | 27 | There are a few solutions to the thread-per-request model. One solution is to add more hardware. This will allow you to increase the number of threads that the Operating System can handle. Another solution is to use asynchronous programming. This will allow you to use a single thread to handle multiple requests. 28 | 29 | ![Scalability Solutions](./images/scalability-solutions.png) 30 | 31 | ## Virtual Threads 32 | 33 | Project Loom introduces a new type of thread called a virtual thread. A virtual thread is a thread that is not tied to an Operating System thread. This means that you can create as many virtual threads as you want without worrying about the Operating System thread limit. 34 | 35 | ![Virtual Threads](./images/virtual-threads.png) 36 | 37 | The nice thing about Virtual Threads in Spring is that for the most part you won't have to change your code. You can continue to write your code in a blocking manner and Spring will take care of the rest. 38 | 39 | While we are in a preview mode there are a few things you will need to do to enable Virtual Threads in Spring. When Virtual Threads are no longer in preview mode you will be able to use them with little to no configuration. 40 | 41 | ## Virtual Threads in Spring Demo 42 | 43 | Before you can run this demo you will need to make sure you have Java 19 installed. 44 | 45 | ```shell 46 | java --version 47 | java 19.0.2 2023-01-17 48 | Java(TM) SE Runtime Environment (build 19.0.2+7-44) 49 | Java HotSpot(TM) 64-Bit Server VM (build 19.0.2+7-44, mixed mode, sharing) 50 | ``` 51 | 52 | Next create a new Spring Boot project using the Spring Initializr. 53 | 54 | ![Spring Initializr](./images/spring-init.png) 55 | 56 | To enable a preview feature in Java you will need to add the following to your `pom.xml` file: 57 | 58 | 59 | ```xml 60 | 61 | 62 | 63 | org.springframework.boot 64 | spring-boot-maven-plugin 65 | 66 | 67 | org.apache.maven.plugins 68 | maven-compiler-plugin 69 | 70 | --enable-preview 71 | 19 72 | 19 73 | 74 | 75 | 76 | 77 | ``` 78 | 79 | Create a new controller called `HomeController` with a method that returns the current thread. 80 | 81 | ```java 82 | @RestController 83 | public class HomeController { 84 | 85 | @GetMapping("/") 86 | public String hello() { 87 | return Thread.currentThread().toString(); 88 | } 89 | 90 | } 91 | ``` 92 | 93 | If you run the application you should see that you are currently using the main thread. 94 | 95 | 96 | ```shell 97 | curl http://localhost:8080/ 98 | Thread[#39,http-nio-8080-exec-1,5,main]% 99 | ``` 100 | 101 | Next you will need to configure Tomcat to use the VirtualThreadPerTaskExecutor. This creates an `Executor` that starts a new virtual thread for each task. The number of threads created by the Executor is unbounded. 102 | 103 | ```java 104 | @SpringBootApplication 105 | public class Application { 106 | 107 | private static final Logger log = LoggerFactory.getLogger(Application.class); 108 | 109 | public static void main(String[] args) { 110 | SpringApplication.run(Application.class, args); 111 | } 112 | 113 | @Bean 114 | TomcatProtocolHandlerCustomizer protocolHandlerVirtualThreadExecutorCustomizer() { 115 | return protocolHandler -> { 116 | log.info("Configuring " + protocolHandler + " to use VirtualThreadPerTaskExecutor"); 117 | protocolHandler.setExecutor(Executors.newVirtualThreadPerTaskExecutor()); 118 | }; 119 | } 120 | 121 | } 122 | ``` 123 | 124 | Run the application again and hit the `/` endpoint and you should now see that you are using a virtual thread. 125 | 126 | ```shell 127 | curl http://localhost:8080/ 128 | VirtualThread[#49]/runnable@ForkJoinPool-1-worker-1% 129 | ``` 130 | 131 | ## Resources 132 | 133 | - [Embracing Virtual Threads](https://spring.io/blog/2022/10/11/embracing-virtual-threads) 134 | - [Web Applications & Project Loom](https://spring.io/blog/2023/02/27/web-applications-and-project-loom) 135 | - [Project Loom](https://jdk.java.net/loom/) 136 | -------------------------------------------------------------------------------- /images/embracing-virtual-threads.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/danvega/loom/ea1d482d08c9564aae128ac193247545ff5664de/images/embracing-virtual-threads.png -------------------------------------------------------------------------------- /images/java-is-made-of-threads.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/danvega/loom/ea1d482d08c9564aae128ac193247545ff5664de/images/java-is-made-of-threads.png -------------------------------------------------------------------------------- /images/scalability-solutions.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/danvega/loom/ea1d482d08c9564aae128ac193247545ff5664de/images/scalability-solutions.png -------------------------------------------------------------------------------- /images/spring-init.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/danvega/loom/ea1d482d08c9564aae128ac193247545ff5664de/images/spring-init.png -------------------------------------------------------------------------------- /images/thread-per-request.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/danvega/loom/ea1d482d08c9564aae128ac193247545ff5664de/images/thread-per-request.png -------------------------------------------------------------------------------- /images/virtual-threads.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/danvega/loom/ea1d482d08c9564aae128ac193247545ff5664de/images/virtual-threads.png -------------------------------------------------------------------------------- /mvnw: -------------------------------------------------------------------------------- 1 | #!/bin/sh 2 | # ---------------------------------------------------------------------------- 3 | # Licensed to the Apache Software Foundation (ASF) under one 4 | # or more contributor license agreements. See the NOTICE file 5 | # distributed with this work for additional information 6 | # regarding copyright ownership. The ASF licenses this file 7 | # to you under the Apache License, Version 2.0 (the 8 | # "License"); you may not use this file except in compliance 9 | # with the License. You may obtain a copy of the License at 10 | # 11 | # https://www.apache.org/licenses/LICENSE-2.0 12 | # 13 | # Unless required by applicable law or agreed to in writing, 14 | # software distributed under the License is distributed on an 15 | # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 | # KIND, either express or implied. See the License for the 17 | # specific language governing permissions and limitations 18 | # under the License. 19 | # ---------------------------------------------------------------------------- 20 | 21 | # ---------------------------------------------------------------------------- 22 | # Maven Start Up Batch script 23 | # 24 | # Required ENV vars: 25 | # ------------------ 26 | # JAVA_HOME - location of a JDK home dir 27 | # 28 | # Optional ENV vars 29 | # ----------------- 30 | # M2_HOME - location of maven2's installed home dir 31 | # MAVEN_OPTS - parameters passed to the Java VM when running Maven 32 | # e.g. to debug Maven itself, use 33 | # set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000 34 | # MAVEN_SKIP_RC - flag to disable loading of mavenrc files 35 | # ---------------------------------------------------------------------------- 36 | 37 | if [ -z "$MAVEN_SKIP_RC" ] ; then 38 | 39 | if [ -f /usr/local/etc/mavenrc ] ; then 40 | . /usr/local/etc/mavenrc 41 | fi 42 | 43 | if [ -f /etc/mavenrc ] ; then 44 | . /etc/mavenrc 45 | fi 46 | 47 | if [ -f "$HOME/.mavenrc" ] ; then 48 | . "$HOME/.mavenrc" 49 | fi 50 | 51 | fi 52 | 53 | # OS specific support. $var _must_ be set to either true or false. 54 | cygwin=false; 55 | darwin=false; 56 | mingw=false 57 | case "`uname`" in 58 | CYGWIN*) cygwin=true ;; 59 | MINGW*) mingw=true;; 60 | Darwin*) darwin=true 61 | # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home 62 | # See https://developer.apple.com/library/mac/qa/qa1170/_index.html 63 | if [ -z "$JAVA_HOME" ]; then 64 | if [ -x "/usr/libexec/java_home" ]; then 65 | export JAVA_HOME="`/usr/libexec/java_home`" 66 | else 67 | export JAVA_HOME="/Library/Java/Home" 68 | fi 69 | fi 70 | ;; 71 | esac 72 | 73 | if [ -z "$JAVA_HOME" ] ; then 74 | if [ -r /etc/gentoo-release ] ; then 75 | JAVA_HOME=`java-config --jre-home` 76 | fi 77 | fi 78 | 79 | if [ -z "$M2_HOME" ] ; then 80 | ## resolve links - $0 may be a link to maven's home 81 | PRG="$0" 82 | 83 | # need this for relative symlinks 84 | while [ -h "$PRG" ] ; do 85 | ls=`ls -ld "$PRG"` 86 | link=`expr "$ls" : '.*-> \(.*\)$'` 87 | if expr "$link" : '/.*' > /dev/null; then 88 | PRG="$link" 89 | else 90 | PRG="`dirname "$PRG"`/$link" 91 | fi 92 | done 93 | 94 | saveddir=`pwd` 95 | 96 | M2_HOME=`dirname "$PRG"`/.. 97 | 98 | # make it fully qualified 99 | M2_HOME=`cd "$M2_HOME" && pwd` 100 | 101 | cd "$saveddir" 102 | # echo Using m2 at $M2_HOME 103 | fi 104 | 105 | # For Cygwin, ensure paths are in UNIX format before anything is touched 106 | if $cygwin ; then 107 | [ -n "$M2_HOME" ] && 108 | M2_HOME=`cygpath --unix "$M2_HOME"` 109 | [ -n "$JAVA_HOME" ] && 110 | JAVA_HOME=`cygpath --unix "$JAVA_HOME"` 111 | [ -n "$CLASSPATH" ] && 112 | CLASSPATH=`cygpath --path --unix "$CLASSPATH"` 113 | fi 114 | 115 | # For Mingw, ensure paths are in UNIX format before anything is touched 116 | if $mingw ; then 117 | [ -n "$M2_HOME" ] && 118 | M2_HOME="`(cd "$M2_HOME"; pwd)`" 119 | [ -n "$JAVA_HOME" ] && 120 | JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`" 121 | fi 122 | 123 | if [ -z "$JAVA_HOME" ]; then 124 | javaExecutable="`which javac`" 125 | if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then 126 | # readlink(1) is not available as standard on Solaris 10. 127 | readLink=`which readlink` 128 | if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then 129 | if $darwin ; then 130 | javaHome="`dirname \"$javaExecutable\"`" 131 | javaExecutable="`cd \"$javaHome\" && pwd -P`/javac" 132 | else 133 | javaExecutable="`readlink -f \"$javaExecutable\"`" 134 | fi 135 | javaHome="`dirname \"$javaExecutable\"`" 136 | javaHome=`expr "$javaHome" : '\(.*\)/bin'` 137 | JAVA_HOME="$javaHome" 138 | export JAVA_HOME 139 | fi 140 | fi 141 | fi 142 | 143 | if [ -z "$JAVACMD" ] ; then 144 | if [ -n "$JAVA_HOME" ] ; then 145 | if [ -x "$JAVA_HOME/jre/sh/java" ] ; then 146 | # IBM's JDK on AIX uses strange locations for the executables 147 | JAVACMD="$JAVA_HOME/jre/sh/java" 148 | else 149 | JAVACMD="$JAVA_HOME/bin/java" 150 | fi 151 | else 152 | JAVACMD="`\\unset -f command; \\command -v java`" 153 | fi 154 | fi 155 | 156 | if [ ! -x "$JAVACMD" ] ; then 157 | echo "Error: JAVA_HOME is not defined correctly." >&2 158 | echo " We cannot execute $JAVACMD" >&2 159 | exit 1 160 | fi 161 | 162 | if [ -z "$JAVA_HOME" ] ; then 163 | echo "Warning: JAVA_HOME environment variable is not set." 164 | fi 165 | 166 | CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher 167 | 168 | # traverses directory structure from process work directory to filesystem root 169 | # first directory with .mvn subdirectory is considered project base directory 170 | find_maven_basedir() { 171 | 172 | if [ -z "$1" ] 173 | then 174 | echo "Path not specified to find_maven_basedir" 175 | return 1 176 | fi 177 | 178 | basedir="$1" 179 | wdir="$1" 180 | while [ "$wdir" != '/' ] ; do 181 | if [ -d "$wdir"/.mvn ] ; then 182 | basedir=$wdir 183 | break 184 | fi 185 | # workaround for JBEAP-8937 (on Solaris 10/Sparc) 186 | if [ -d "${wdir}" ]; then 187 | wdir=`cd "$wdir/.."; pwd` 188 | fi 189 | # end of workaround 190 | done 191 | echo "${basedir}" 192 | } 193 | 194 | # concatenates all lines of a file 195 | concat_lines() { 196 | if [ -f "$1" ]; then 197 | echo "$(tr -s '\n' ' ' < "$1")" 198 | fi 199 | } 200 | 201 | BASE_DIR=`find_maven_basedir "$(pwd)"` 202 | if [ -z "$BASE_DIR" ]; then 203 | exit 1; 204 | fi 205 | 206 | ########################################################################################## 207 | # Extension to allow automatically downloading the maven-wrapper.jar from Maven-central 208 | # This allows using the maven wrapper in projects that prohibit checking in binary data. 209 | ########################################################################################## 210 | if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then 211 | if [ "$MVNW_VERBOSE" = true ]; then 212 | echo "Found .mvn/wrapper/maven-wrapper.jar" 213 | fi 214 | else 215 | if [ "$MVNW_VERBOSE" = true ]; then 216 | echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..." 217 | fi 218 | if [ -n "$MVNW_REPOURL" ]; then 219 | jarUrl="$MVNW_REPOURL/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar" 220 | else 221 | jarUrl="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar" 222 | fi 223 | while IFS="=" read key value; do 224 | case "$key" in (wrapperUrl) jarUrl="$value"; break ;; 225 | esac 226 | done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties" 227 | if [ "$MVNW_VERBOSE" = true ]; then 228 | echo "Downloading from: $jarUrl" 229 | fi 230 | wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" 231 | if $cygwin; then 232 | wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"` 233 | fi 234 | 235 | if command -v wget > /dev/null; then 236 | if [ "$MVNW_VERBOSE" = true ]; then 237 | echo "Found wget ... using wget" 238 | fi 239 | if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then 240 | wget "$jarUrl" -O "$wrapperJarPath" || rm -f "$wrapperJarPath" 241 | else 242 | wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath" || rm -f "$wrapperJarPath" 243 | fi 244 | elif command -v curl > /dev/null; then 245 | if [ "$MVNW_VERBOSE" = true ]; then 246 | echo "Found curl ... using curl" 247 | fi 248 | if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then 249 | curl -o "$wrapperJarPath" "$jarUrl" -f 250 | else 251 | curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f 252 | fi 253 | 254 | else 255 | if [ "$MVNW_VERBOSE" = true ]; then 256 | echo "Falling back to using Java to download" 257 | fi 258 | javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java" 259 | # For Cygwin, switch paths to Windows format before running javac 260 | if $cygwin; then 261 | javaClass=`cygpath --path --windows "$javaClass"` 262 | fi 263 | if [ -e "$javaClass" ]; then 264 | if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then 265 | if [ "$MVNW_VERBOSE" = true ]; then 266 | echo " - Compiling MavenWrapperDownloader.java ..." 267 | fi 268 | # Compiling the Java class 269 | ("$JAVA_HOME/bin/javac" "$javaClass") 270 | fi 271 | if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then 272 | # Running the downloader 273 | if [ "$MVNW_VERBOSE" = true ]; then 274 | echo " - Running MavenWrapperDownloader.java ..." 275 | fi 276 | ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR") 277 | fi 278 | fi 279 | fi 280 | fi 281 | ########################################################################################## 282 | # End of extension 283 | ########################################################################################## 284 | 285 | export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"} 286 | if [ "$MVNW_VERBOSE" = true ]; then 287 | echo $MAVEN_PROJECTBASEDIR 288 | fi 289 | MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS" 290 | 291 | # For Cygwin, switch paths to Windows format before running java 292 | if $cygwin; then 293 | [ -n "$M2_HOME" ] && 294 | M2_HOME=`cygpath --path --windows "$M2_HOME"` 295 | [ -n "$JAVA_HOME" ] && 296 | JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"` 297 | [ -n "$CLASSPATH" ] && 298 | CLASSPATH=`cygpath --path --windows "$CLASSPATH"` 299 | [ -n "$MAVEN_PROJECTBASEDIR" ] && 300 | MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"` 301 | fi 302 | 303 | # Provide a "standardized" way to retrieve the CLI args that will 304 | # work with both Windows and non-Windows executions. 305 | MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@" 306 | export MAVEN_CMD_LINE_ARGS 307 | 308 | WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain 309 | 310 | exec "$JAVACMD" \ 311 | $MAVEN_OPTS \ 312 | $MAVEN_DEBUG_OPTS \ 313 | -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \ 314 | "-Dmaven.home=${M2_HOME}" \ 315 | "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \ 316 | ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@" 317 | -------------------------------------------------------------------------------- /mvnw.cmd: -------------------------------------------------------------------------------- 1 | @REM ---------------------------------------------------------------------------- 2 | @REM Licensed to the Apache Software Foundation (ASF) under one 3 | @REM or more contributor license agreements. See the NOTICE file 4 | @REM distributed with this work for additional information 5 | @REM regarding copyright ownership. The ASF licenses this file 6 | @REM to you under the Apache License, Version 2.0 (the 7 | @REM "License"); you may not use this file except in compliance 8 | @REM with the License. You may obtain a copy of the License at 9 | @REM 10 | @REM https://www.apache.org/licenses/LICENSE-2.0 11 | @REM 12 | @REM Unless required by applicable law or agreed to in writing, 13 | @REM software distributed under the License is distributed on an 14 | @REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 | @REM KIND, either express or implied. See the License for the 16 | @REM specific language governing permissions and limitations 17 | @REM under the License. 18 | @REM ---------------------------------------------------------------------------- 19 | 20 | @REM ---------------------------------------------------------------------------- 21 | @REM Maven Start Up Batch script 22 | @REM 23 | @REM Required ENV vars: 24 | @REM JAVA_HOME - location of a JDK home dir 25 | @REM 26 | @REM Optional ENV vars 27 | @REM M2_HOME - location of maven2's installed home dir 28 | @REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands 29 | @REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending 30 | @REM MAVEN_OPTS - parameters passed to the Java VM when running Maven 31 | @REM e.g. to debug Maven itself, use 32 | @REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000 33 | @REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files 34 | @REM ---------------------------------------------------------------------------- 35 | 36 | @REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on' 37 | @echo off 38 | @REM set title of command window 39 | title %0 40 | @REM enable echoing by setting MAVEN_BATCH_ECHO to 'on' 41 | @if "%MAVEN_BATCH_ECHO%" == "on" echo %MAVEN_BATCH_ECHO% 42 | 43 | @REM set %HOME% to equivalent of $HOME 44 | if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%") 45 | 46 | @REM Execute a user defined script before this one 47 | if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre 48 | @REM check for pre script, once with legacy .bat ending and once with .cmd ending 49 | if exist "%USERPROFILE%\mavenrc_pre.bat" call "%USERPROFILE%\mavenrc_pre.bat" %* 50 | if exist "%USERPROFILE%\mavenrc_pre.cmd" call "%USERPROFILE%\mavenrc_pre.cmd" %* 51 | :skipRcPre 52 | 53 | @setlocal 54 | 55 | set ERROR_CODE=0 56 | 57 | @REM To isolate internal variables from possible post scripts, we use another setlocal 58 | @setlocal 59 | 60 | @REM ==== START VALIDATION ==== 61 | if not "%JAVA_HOME%" == "" goto OkJHome 62 | 63 | echo. 64 | echo Error: JAVA_HOME not found in your environment. >&2 65 | echo Please set the JAVA_HOME variable in your environment to match the >&2 66 | echo location of your Java installation. >&2 67 | echo. 68 | goto error 69 | 70 | :OkJHome 71 | if exist "%JAVA_HOME%\bin\java.exe" goto init 72 | 73 | echo. 74 | echo Error: JAVA_HOME is set to an invalid directory. >&2 75 | echo JAVA_HOME = "%JAVA_HOME%" >&2 76 | echo Please set the JAVA_HOME variable in your environment to match the >&2 77 | echo location of your Java installation. >&2 78 | echo. 79 | goto error 80 | 81 | @REM ==== END VALIDATION ==== 82 | 83 | :init 84 | 85 | @REM Find the project base dir, i.e. the directory that contains the folder ".mvn". 86 | @REM Fallback to current working directory if not found. 87 | 88 | set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR% 89 | IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir 90 | 91 | set EXEC_DIR=%CD% 92 | set WDIR=%EXEC_DIR% 93 | :findBaseDir 94 | IF EXIST "%WDIR%"\.mvn goto baseDirFound 95 | cd .. 96 | IF "%WDIR%"=="%CD%" goto baseDirNotFound 97 | set WDIR=%CD% 98 | goto findBaseDir 99 | 100 | :baseDirFound 101 | set MAVEN_PROJECTBASEDIR=%WDIR% 102 | cd "%EXEC_DIR%" 103 | goto endDetectBaseDir 104 | 105 | :baseDirNotFound 106 | set MAVEN_PROJECTBASEDIR=%EXEC_DIR% 107 | cd "%EXEC_DIR%" 108 | 109 | :endDetectBaseDir 110 | 111 | IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig 112 | 113 | @setlocal EnableExtensions EnableDelayedExpansion 114 | for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a 115 | @endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS% 116 | 117 | :endReadAdditionalConfig 118 | 119 | SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe" 120 | set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar" 121 | set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain 122 | 123 | set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar" 124 | 125 | FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO ( 126 | IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B 127 | ) 128 | 129 | @REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central 130 | @REM This allows using the maven wrapper in projects that prohibit checking in binary data. 131 | if exist %WRAPPER_JAR% ( 132 | if "%MVNW_VERBOSE%" == "true" ( 133 | echo Found %WRAPPER_JAR% 134 | ) 135 | ) else ( 136 | if not "%MVNW_REPOURL%" == "" ( 137 | SET DOWNLOAD_URL="%MVNW_REPOURL%/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar" 138 | ) 139 | if "%MVNW_VERBOSE%" == "true" ( 140 | echo Couldn't find %WRAPPER_JAR%, downloading it ... 141 | echo Downloading from: %DOWNLOAD_URL% 142 | ) 143 | 144 | powershell -Command "&{"^ 145 | "$webclient = new-object System.Net.WebClient;"^ 146 | "if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^ 147 | "$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^ 148 | "}"^ 149 | "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^ 150 | "}" 151 | if "%MVNW_VERBOSE%" == "true" ( 152 | echo Finished downloading %WRAPPER_JAR% 153 | ) 154 | ) 155 | @REM End of extension 156 | 157 | @REM Provide a "standardized" way to retrieve the CLI args that will 158 | @REM work with both Windows and non-Windows executions. 159 | set MAVEN_CMD_LINE_ARGS=%* 160 | 161 | %MAVEN_JAVA_EXE% ^ 162 | %JVM_CONFIG_MAVEN_PROPS% ^ 163 | %MAVEN_OPTS% ^ 164 | %MAVEN_DEBUG_OPTS% ^ 165 | -classpath %WRAPPER_JAR% ^ 166 | "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" ^ 167 | %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %* 168 | if ERRORLEVEL 1 goto error 169 | goto end 170 | 171 | :error 172 | set ERROR_CODE=1 173 | 174 | :end 175 | @endlocal & set ERROR_CODE=%ERROR_CODE% 176 | 177 | if not "%MAVEN_SKIP_RC%"=="" goto skipRcPost 178 | @REM check for post script, once with legacy .bat ending and once with .cmd ending 179 | if exist "%USERPROFILE%\mavenrc_post.bat" call "%USERPROFILE%\mavenrc_post.bat" 180 | if exist "%USERPROFILE%\mavenrc_post.cmd" call "%USERPROFILE%\mavenrc_post.cmd" 181 | :skipRcPost 182 | 183 | @REM pause the script if MAVEN_BATCH_PAUSE is set to 'on' 184 | if "%MAVEN_BATCH_PAUSE%"=="on" pause 185 | 186 | if "%MAVEN_TERMINATE_CMD%"=="on" exit %ERROR_CODE% 187 | 188 | cmd /C exit /B %ERROR_CODE% 189 | -------------------------------------------------------------------------------- /pom.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 5 | 4.0.0 6 | 7 | org.springframework.boot 8 | spring-boot-starter-parent 9 | 3.0.4 10 | 11 | 12 | com.devnexus 13 | loom 14 | 0.0.1-SNAPSHOT 15 | loom 16 | Demo project for Spring Boot 17 | 18 | 19 19 | 11.0.0-M4 20 | 21 | 22 | 23 | org.springframework.boot 24 | spring-boot-starter-web 25 | 26 | 27 | org.springframework.boot 28 | spring-boot-starter-test 29 | test 30 | 31 | 32 | 33 | 34 | 35 | 36 | org.springframework.boot 37 | spring-boot-maven-plugin 38 | 39 | 40 | org.apache.maven.plugins 41 | maven-compiler-plugin 42 | 43 | --enable-preview 44 | 19 45 | 19 46 | 47 | 48 | 49 | 50 | 51 | 52 | -------------------------------------------------------------------------------- /src/main/java/com/devnexus/loom/Application.java: -------------------------------------------------------------------------------- 1 | package com.devnexus.loom; 2 | 3 | import org.slf4j.Logger; 4 | import org.slf4j.LoggerFactory; 5 | import org.springframework.boot.SpringApplication; 6 | import org.springframework.boot.autoconfigure.SpringBootApplication; 7 | import org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration; 8 | import org.springframework.boot.web.embedded.tomcat.TomcatProtocolHandlerCustomizer; 9 | import org.springframework.context.annotation.Bean; 10 | import org.springframework.core.task.AsyncTaskExecutor; 11 | import org.springframework.core.task.support.TaskExecutorAdapter; 12 | 13 | import java.util.concurrent.Executors; 14 | 15 | @SpringBootApplication 16 | public class Application { 17 | 18 | private static final Logger log = LoggerFactory.getLogger(Application.class); 19 | 20 | public static void main(String[] args) { 21 | SpringApplication.run(Application.class, args); 22 | } 23 | 24 | @Bean 25 | TomcatProtocolHandlerCustomizer protocolHandlerVirtualThreadExecutorCustomizer() { 26 | return protocolHandler -> { 27 | log.info("Configuring " + protocolHandler + " to use VirtualThreadPerTaskExecutor"); 28 | protocolHandler.setExecutor(Executors.newVirtualThreadPerTaskExecutor()); 29 | }; 30 | } 31 | 32 | } 33 | -------------------------------------------------------------------------------- /src/main/java/com/devnexus/loom/HomeController.java: -------------------------------------------------------------------------------- 1 | package com.devnexus.loom; 2 | 3 | import org.springframework.web.bind.annotation.GetMapping; 4 | import org.springframework.web.bind.annotation.RestController; 5 | 6 | @RestController 7 | public class HomeController { 8 | 9 | @GetMapping("/") 10 | public String hello() { 11 | return Thread.currentThread().toString(); 12 | } 13 | 14 | } 15 | -------------------------------------------------------------------------------- /src/main/resources/application.properties: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/danvega/loom/ea1d482d08c9564aae128ac193247545ff5664de/src/main/resources/application.properties --------------------------------------------------------------------------------