feat(*): add ligning talk with example code

.gitignore

@@ -39,9 +39,5 @@
 # JIRA plugin
 atlassian-ide-plugin.xml
 
-# Crashlytics plugin (for Android Studio and IntelliJ)
-com_crashlytics_export_strings.xml
-crashlytics.properties
-crashlytics-build.properties
-fabric.properties
+target/
 

java9-in-action.iml

@@ -3,7 +3,6 @@
   <component name="NewModuleRootManager" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
-      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
       <excludeFolder url="file://$MODULE_DIR$/presentation/css" />
       <excludeFolder url="file://$MODULE_DIR$/presentation/img" />
       <excludeFolder url="file://$MODULE_DIR$/presentation/js" />

playground-dependent/playground-dependent.iml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="module" module-name="playground" />
+  </component>
+</module>

playground-dependent/run-with-modules

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+echo -e "\nHINT: Be sure to compile project with IDEA first\n"
+
+echo -e "=== RetrieveModuleInfo"
+java -modulepath ../target/production/playground:../target/production/playground-dependent  \
+    -m anothermodule/de.exxcellent.anothermodule.RetrieveModuleInfo
+
+
+echo -e "\n\n=== TestJigsawSPI"
+java -modulepath ../target/production/playground:../target/production/playground-dependent  \
+    -m anothermodule/de.exxcellent.anothermodule.TestJigsawSPI

playground-dependent/src/main/java/de/exxcellent/anothermodule/RetrieveModuleInfo.java

@@ -0,0 +1,40 @@
+package de.exxcellent.anothermodule;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.module.ModuleDescriptor;
+import static java.lang.System.out;
+
+public class RetrieveModuleInfo {
+
+    /**
+     * Show module infos
+     */
+    public static void main(String[] args) throws IOException {
+        ModuleDescriptor descriptor = RetrieveModuleInfo.class.getModule().getDescriptor();
+
+        if (descriptor == null) {
+            out.println("JVM started without '-mp' option. Trying to load module-info manually...");
+            descriptor = readModuleDescriptorFromBytecode();
+        }
+
+        printModule(descriptor);
+    }
+
+    static void printModule(ModuleDescriptor descriptor) {
+        out.println("Module " + descriptor.name());
+        descriptor.exports().forEach(
+                export -> out.println("\texports " + export.source())
+        );
+        descriptor.requires().forEach(
+                requires -> out.println("\trequires " + requires.name() + " " + requires.modifiers())
+        );
+    }
+
+    static ModuleDescriptor readModuleDescriptorFromBytecode() throws IOException {
+        InputStream moduleInfo = RetrieveModuleInfo.class.getClassLoader().getResourceAsStream("module-info.class");
+        return ModuleDescriptor.read(moduleInfo);
+    }
+
+
+}

playground-dependent/src/main/java/de/exxcellent/anothermodule/TestJigsawSPI.java

@@ -0,0 +1,12 @@
+package de.exxcellent.anothermodule;
+
+import de.exxcellent.java9.jigsaw.BillingService;
+import static java.lang.System.out;
+
+public class TestJigsawSPI {
+
+    public static void main(String[] args) {
+        BillingService s = BillingService.getInstance();
+        out.println(s.takeMoney());
+    }
+}

playground-dependent/src/main/java/de/exxcellent/anothermodule/TestModuleEncapuslation.java

@@ -0,0 +1,17 @@
+package de.exxcellent.anothermodule;
+
+import de.exxcellent.java9.collections.ImmutableCollections;
+
+/**
+ * Test module encapsulation
+ */
+public class TestModuleEncapuslation {
+
+    public static void main(String[] args) {
+        ImmutableCollections.main(args);
+
+        // Would break, as it is not exported. Though it's public!
+        // de.exxcellent.java9.util.InputStreamExample.main(args);
+    }
+
+}

playground-dependent/src/main/java/de/exxcellent/anothermodule/module-info.java

@@ -0,0 +1,8 @@
+module anothermodule {
+    exports de.exxcellent.anothermodule;
+    requires de.exxcellent.java9;
+
+    // Provide Service instance (SPI with Jigsaw modules)
+    provides de.exxcellent.java9.jigsaw.spi.BillingServiceProvider
+    with de.exxcellent.anothermodule.spi.MastercardBillingServiceProvider;
+}

playground-dependent/src/main/java/de/exxcellent/anothermodule/spi/MastercardBillingService.java

@@ -0,0 +1,11 @@
+package de.exxcellent.anothermodule.spi;
+
+import de.exxcellent.java9.jigsaw.BillingService;
+
+class MastercardBillingService extends BillingService {
+
+    @Override
+    public String takeMoney() {
+        return "Mastercard billed the money!";
+    }
+}

playground-dependent/src/main/java/de/exxcellent/anothermodule/spi/MastercardBillingServiceProvider.java

@@ -0,0 +1,12 @@
+package de.exxcellent.anothermodule.spi;
+
+import de.exxcellent.java9.jigsaw.BillingService;
+import de.exxcellent.java9.jigsaw.spi.BillingServiceProvider;
+
+public class MastercardBillingServiceProvider extends BillingServiceProvider {
+
+    @Override
+    public BillingService buildBillingService() {
+        return new MastercardBillingService();
+    }
+}

playground/playground.iml

@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
-    <exclude-output />
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_9" inherit-compiler-output="true">
     <content url="file://$MODULE_DIR$">
-      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />

playground/src/main/java/de/exxcellent/java9/collections/ImmutableCollections.java

@@ -0,0 +1,31 @@
+package de.exxcellent.java9.collections;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import static java.lang.System.*;
+
+public class ImmutableCollections {
+
+    /**
+     * Create immutable collections on the fly.
+     * They do not accept {@code null} or duplicate entries (Set/Map)
+     */
+    public static void main(String args[]) {
+        List<Integer> listOfNumbers = List.of(1, 2, 3, 4, 5/*, null*/);
+        out.println(listOfNumbers);
+
+        Set<Integer> setOfNumbers = Set.of(1, 2, 3, 4, 5/*, 1*/);
+        out.println(setOfNumbers);
+
+        Map<String, String> mapOfString = Map.of("key1", "value1", "key2", "value2");
+        out.println(mapOfString);
+
+        Map<String, String> moreMapOfString = Map.ofEntries(
+                Map.entry("key1", "value1"),
+                Map.entry("key2", "value2")/*,
+                Map.entry("key1", "value3")*/
+        );
+        out.println(moreMapOfString);
+    }
+}

playground/src/main/java/de/exxcellent/java9/http/HttpClientExample.java

@@ -0,0 +1,25 @@
+package de.exxcellent.java9.http;
+
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpResponse;
+import static java.lang.System.out;
+
+public class HttpClientExample {
+
+    /**
+     * The HTTP API functions asynchronously & synchronously. In asynchronous mode,
+     * work is done on the threads supplied by the client's ExecutorService.
+     */
+    public static void main(String[] args) throws Exception{
+        HttpClient.getDefault()
+                .request(URI.create("https://www.exxcellent.de"))
+                .GET()
+                .responseAsync() // CompletableFuture :D
+                .thenAccept(httpResponse ->
+                                    out.println(httpResponse.body(HttpResponse.asString()))
+                );
+
+        Thread.sleep(999); // Give worker thread some time.
+    }
+}

playground/src/main/java/de/exxcellent/java9/jigsaw/BillingService.java

@@ -0,0 +1,28 @@
+package de.exxcellent.java9.jigsaw;
+
+import java.util.Iterator;
+import java.util.ServiceLoader;
+import de.exxcellent.java9.jigsaw.spi.BillingServiceProvider;
+
+public abstract class BillingService {
+
+    protected BillingService() {
+    }
+
+    public static BillingService getInstance() {
+        // Java SPI to find the instance
+        ServiceLoader<BillingServiceProvider> sl = ServiceLoader.load(BillingServiceProvider.class);
+
+        // Fetch first provider implementation
+        Iterator<BillingServiceProvider> providerIterator = sl.iterator();
+        if (!providerIterator.hasNext()) {
+            throw new RuntimeException("No service providers found!");
+        }
+
+        BillingServiceProvider provider = providerIterator.next();
+
+        return provider.buildBillingService();
+    }
+
+    public abstract String takeMoney();
+}

playground/src/main/java/de/exxcellent/java9/jigsaw/spi/BillingServiceProvider.java

@@ -0,0 +1,8 @@
+package de.exxcellent.java9.jigsaw.spi;
+
+import de.exxcellent.java9.jigsaw.BillingService;
+
+public abstract class BillingServiceProvider {
+
+    public abstract BillingService buildBillingService();
+}

playground/src/main/java/de/exxcellent/java9/module-info.java

@@ -0,0 +1,12 @@
+module de.exxcellent.java9 {
+    exports de.exxcellent.java9.collections;
+
+    // Depend on an offficial JDK modules
+    //    full list see http://cr.openjdk.java.net/~mr/jigsaw/ea/module-summary.html
+    requires java.httpclient;
+
+    // Service example  (SPI with Jigsaw modules)
+    exports de.exxcellent.java9.jigsaw;
+    exports de.exxcellent.java9.jigsaw.spi;
+    uses de.exxcellent.java9.jigsaw.spi.BillingServiceProvider;
+}