example repo

build.gradle

@@ -0,0 +1,25 @@
+apply plugin: 'java'
+apply plugin: 'idea'
+apply plugin: 'application'
+
+
+repositories {
+    mavenCentral()
+    mavenLocal()
+    maven {
+        url "https://repo.akka.io/maven"
+    }
+}
+
+dependencies {
+  implementation 'com.typesafe.akka:akka-actor-typed_2.13:2.9.2'
+  implementation 'ch.qos.logback:logback-classic:1.2.3'
+  testImplementation 'com.typesafe.akka:akka-actor-testkit-typed_2.13:2.9.2'
+  testImplementation 'junit:junit:4.13.1'
+}
+
+mainClassName = "com.example.AkkaStart"
+
+run {
+  standardInput = System.in
+}

build/resources/main/logback.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <!-- This is a development logging configuration that logs to standard out, for an example of a production
+        logging config, see the Akka docs: https://doc.akka.io/docs/akka/2.6/typed/logging.html#logback -->
+    <appender name="STDOUT" target="System.out" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>[%date{ISO8601}] [%level] [%logger] [%thread] [%X{akkaSource}] - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <appender name="ASYNC" class="ch.qos.logback.classic.AsyncAppender">
+        <queueSize>1024</queueSize>
+        <neverBlock>true</neverBlock>
+        <appender-ref ref="STDOUT" />
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="ASYNC"/>
+    </root>
+
+</configuration>

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,251 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# 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
+#
+#      https://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.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,94 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

src/main/java/com/example/Add.java

@@ -0,0 +1,112 @@
+package com.example;
+
+import akka.actor.typed.javadsl.TimerScheduler;
+import akka.actor.typed.ActorRef;
+import akka.actor.typed.Behavior;
+import akka.actor.typed.javadsl.AbstractBehavior;
+import akka.actor.typed.javadsl.ActorContext;
+import akka.actor.typed.javadsl.Behaviors;
+import akka.actor.typed.javadsl.Receive;
+
+import java.time.Duration;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class Add extends AbstractBehavior<Add.Addition> {
+    public interface Addition {};
+
+    public record EvalAndWait(String left, String right) implements Addition {}
+    public record EvalAndCheck(String left, String right) implements Addition {}
+    public record Result(int result, String side) implements Addition {}
+    public record AddResult() implements Addition {}
+    public record PrintResult() implements Addition {}
+    public record WaitForResult() implements Addition {}
+    public record SetResults(int result, String side) implements Addition {}
+
+
+    public static Behavior<Addition> create(){
+        return Behaviors.setup(context -> Behaviors.withTimers(timers -> new Add(context, timers)) );
+    }
+
+    public int result;
+    public List<Integer> results;
+    private final TimerScheduler<Addition> timers;
+
+    private Add(ActorContext<Addition> context, TimerScheduler<Addition> timers){
+        super(context);
+        this.timers = timers;
+        this.result = 0;
+        this.results = Arrays.asList(null, null);
+    }
+
+    @Override
+    public Receive<Addition> createReceive() {
+        return newReceiveBuilder()
+                .onMessage(EvalAndWait.class, this::onEvalAndWait)
+                .onMessage(EvalAndCheck.class, this::onEvalAndCheck)
+                .onMessage(Result.class, this::onResult)
+                .onMessage(PrintResult.class, this::onPrintResult)
+                .onMessage(WaitForResult.class, this::onWaitForResult)
+                .onMessage(SetResults.class, this::onSetResults)
+                .onMessage(AddResult.class, this::onAddResult)
+                .build();
+    }
+
+    private Behavior<Addition> onEvalAndWait(EvalAndWait msg){
+        ActorRef<Val.Value> left = getContext().spawnAnonymous(Val.create("left"));
+        ActorRef<Val.Value> right = getContext().spawnAnonymous(Val.create("right"));
+        left.tell(new Val.Eval(msg.left));
+        right.tell(new Val.Eval(msg.right));
+        left.tell(new Val.Result(getContext().getSelf()));
+        right.tell(new Val.Result(getContext().getSelf()));
+        getContext().getSelf().tell(new WaitForResult());
+        return this;
+    }
+    private Behavior<Addition> onResult(Result msg){
+        this.result += msg.result;
+        getContext().getLog().info("Calculating: {}", this.result);
+        return this;
+    }
+
+    private Behavior<Addition> onPrintResult(PrintResult msg){
+        getContext().getLog().info("Result: {}", this.result);
+        return this;
+    }
+
+    private Behavior<Addition> onWaitForResult(WaitForResult msg){
+        this.timers.startSingleTimer(new PrintResult(), Duration.ofSeconds(1));
+        return this;
+    }
+
+    private Behavior<Addition> onEvalAndCheck(EvalAndCheck msg){
+        ActorRef<Val.Value> left = getContext().spawnAnonymous(Val.create("left"));
+        ActorRef<Val.Value> right = getContext().spawnAnonymous(Val.create("right"));
+        left.tell(new Val.Eval(msg.left));
+        right.tell(new Val.Eval(msg.right));
+        left.tell(new Val.SetResults(getContext().getSelf()));
+        right.tell(new Val.SetResults(getContext().getSelf()));
+        getContext().getSelf().tell(new AddResult());
+        return this;
+    }
+
+    private Behavior<Addition> onSetResults(SetResults msg){
+        if (msg.side == "left" && this.results.get(0) == null){
+            this.results.set(0, msg.result);
+        } else if (msg.side == "right" && this.results.get(1) == null) {
+            this.results.set(1, msg.result);
+        }
+        return this;
+    }
+
+    private Behavior<Addition> onAddResult(AddResult msg){
+        if (this.results.get(0) == null || this.results.get(1) == null){
+            getContext().getSelf().tell(new AddResult());
+            return this;
+        }
+        int sum = this.results.stream().mapToInt(i -> i).sum();
+        this.result = sum;
+        getContext().getSelf().tell(new PrintResult());
+        return this;
+    }
+}

src/main/java/com/example/AkkaMainSystem.java

@@ -0,0 +1,34 @@
+package com.example;
+
+import akka.actor.typed.ActorRef;
+import akka.actor.typed.Behavior;
+import akka.actor.typed.javadsl.*;
+
+public class AkkaMainSystem extends AbstractBehavior<AkkaMainSystem.Create> {
+
+    public static class Create {
+    }
+
+    public static Behavior<Create> create() {
+        return Behaviors.setup(AkkaMainSystem::new);
+    }
+
+    private AkkaMainSystem(ActorContext<Create> context) {
+        super(context);
+    }
+
+    @Override
+    public Receive<Create> createReceive() {
+        return newReceiveBuilder().onMessage(Create.class, this::onCreate).build();
+    }
+
+    private Behavior<Create> onCreate(Create command) {
+        var addition = this.getContext().spawn(Add.create(), "Addition");
+        addition.tell(new Add.EvalAndWait("3", "5"));
+
+        var addition_check = this.getContext().spawn(Add.create(), "AdditionCheck");
+        addition_check.tell(new Add.EvalAndCheck("4", "6"));
+
+        return this;
+    }
+}

src/main/java/com/example/AkkaStart.java

@@ -0,0 +1,20 @@
+package com.example;
+
+import akka.actor.typed.ActorSystem;
+
+import java.io.IOException;
+public class AkkaStart {
+  public static void main(String[] args) {
+    final ActorSystem<AkkaMainSystem.Create> messageMain = ActorSystem.create(AkkaMainSystem.create(), "akkaMainSystem");
+
+    messageMain.tell(new AkkaMainSystem.Create());
+
+    try {
+      System.out.println(">>> Press ENTER to exit <<<");
+      System.in.read();
+    } catch (IOException ignored) {
+    } finally {
+      messageMain.terminate();
+    }
+  }
+}

src/main/java/com/example/Val.java

@@ -0,0 +1,57 @@
+package com.example;
+
+import akka.actor.typed.ActorRef;
+import akka.actor.typed.Behavior;
+import akka.actor.typed.javadsl.AbstractBehavior;
+import akka.actor.typed.javadsl.ActorContext;
+import akka.actor.typed.javadsl.Behaviors;
+import akka.actor.typed.javadsl.Receive;
+
+public class Val extends AbstractBehavior<Val.Value> {
+    public interface Value {};
+
+    public record Eval(String expr) implements Value {}
+    public record Result(ActorRef<Add.Addition> replyTo) implements Value{}
+    public record SetResults(ActorRef<Add.Addition> replyTo) implements Value{}
+
+
+    public static Behavior<Value> create (String termSide){
+        return Behaviors.setup(context -> new Val(context, termSide));
+    }
+    public int result;
+    public final String termside;
+
+    private Val(ActorContext<Value> context, String termSide){
+        super(context);
+        this.termside = termSide;
+    }
+
+    public Receive<Value> createReceive(){
+        return newReceiveBuilder()
+                .onMessage(Eval.class, this::onEval)
+                .onMessage(Result.class, this::onResult)
+                .onMessage(SetResults.class, this::onSetResults)
+                .build();
+    }
+
+    private Behavior<Value> onEval(Eval msg){
+        this.result = Integer.parseInt(msg.expr);
+        getContext().getLog().info("Val: {}", this.result);
+        return this;
+    }
+
+    private Behavior<Value> onResult(Result msg){
+        int result = this.result;
+        String side = this.termside;
+        msg.replyTo.tell(new Add.Result(result, side));
+        return this;
+    }
+
+    private Behavior<Value> onSetResults(SetResults msg){
+        int result = this.result;
+        String side = this.termside;
+        msg.replyTo.tell(new Add.SetResults(result, side));
+        return this;
+    }
+
+}

src/main/resources/logback.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <!-- This is a development logging configuration that logs to standard out, for an example of a production
+        logging config, see the Akka docs: https://doc.akka.io/docs/akka/2.6/typed/logging.html#logback -->
+    <appender name="STDOUT" target="System.out" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>[%date{ISO8601}] [%level] [%logger] [%thread] [%X{akkaSource}] - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <appender name="ASYNC" class="ch.qos.logback.classic.AsyncAppender">
+        <queueSize>1024</queueSize>
+        <neverBlock>true</neverBlock>
+        <appender-ref ref="STDOUT" />
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="ASYNC"/>
+    </root>
+
+</configuration>