Update to remove mvn exec and use java -jar fatjar for examples (#227)

* 1. Added Spring boot maven plugin to create fat jar.
2. Created new main class as entry point for the fat jar.
3. Updated Readme and comments for all the examples

* 1) Configured spring boot maven plugin to not include version in the generated fat jar name and updated readme and comments
2) Removed SpringBootApplication annotation from DaprMainApplication.
3) Minor formating changes

* Update DaprMainApplication.java

Co-authored-by: Artur Souza <artursouza.ms@outlook.com>

examples/pom.xml

@@ -143,6 +143,22 @@
           <skip>true</skip>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <goals>
+              <goal>repackage</goal>
+            </goals>
+            <configuration>
+              <mainClass>io.dapr.springboot.DaprMainApplication</mainClass>
+              <classifier>exec</classifier>
+              <finalName>dapr-java-sdk-examples</finalName>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
     </plugins>
   </build>
 </project>

examples/src/main/java/io/dapr/examples/actors/http/DemoActorClient.java

@@ -17,8 +17,8 @@ import java.util.List;
  * 1. Build and install jars:
  * mvn clean install
  * 2. Run the client:
- * dapr run --app-id demoactorclient --port 3006 -- mvn exec:java \
+ * dapr run --app-id demoactorclient --port 3006 -- java -jar \
- * -pl=examples -Dexec.mainClass=io.dapr.examples.actors.http.DemoActorClient
+ * examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.actors.http.DemoActorClient
  */
 public class DemoActorClient {
 

examples/src/main/java/io/dapr/examples/actors/http/DemoActorService.java

@@ -18,7 +18,8 @@ import org.apache.commons.cli.Options;
  * mvn clean install
  * 2. Run the server:
  * dapr run --app-id demoactorservice --app-port 3000 --port 3005 \
- *   -- mvn exec:java -pl=examples -Dexec.mainClass=io.dapr.examples.actors.http.DemoActorService -Dexec.args="-p 3000"
+ *   -- java -jar examples/target/dapr-java-sdk-examples-exec.jar \
+ *   io.dapr.examples.actors.http.DemoActorService -p 3000
  */
 public class DemoActorService {
 

examples/src/main/java/io/dapr/examples/actors/http/README.md

@@ -105,7 +105,7 @@ An actor inherits from `AbstractActor` and implements the constructor to pass th
 Now, execute the following script in order to run DemoActorService:
 ```sh
 cd to [repo-root]
-dapr run --app-id demoactorservice --app-port 3000 --port 3005 -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.actors.http.DemoActorService -D exec.args="-p 3000"
+dapr run --app-id demoactorservice --app-port 3000 --port 3005 -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.actors.http.DemoActorService -p 3000
 ```
 
 ### Running the Actor client
@@ -164,7 +164,7 @@ Use the follow command to execute the DemoActorClient:
 
 ```sh
 cd to [repo-root]
-dapr run --app-id demoactorclient --port 3006 -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.actors.http.DemoActorClient
+dapr run --app-id demoactorclient --port 3006 -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.actors.http.DemoActorClient
 ```
 
 Once running, the `DemoActorClient` logs will start displaying the different steps: 

examples/src/main/java/io/dapr/examples/bindings/http/InputBindingExample.java

@@ -18,7 +18,8 @@ import org.apache.commons.cli.Options;
  * 2. cd to [repo-root]/examples
  * 3. Run :
  * dapr run --app-id inputbinding --app-port 3000 --port 3005  \
- *   -- mvn exec:java -D exec.mainClass=io.dapr.examples.bindings.http.InputBindingExample -D exec.args="-p 3000"
+ *   -- java -jar target/dapr-java-sdk-examples-exec.jar \
+ *   io.dapr.examples.bindings.http.InputBindingExample -p 3000
  */
 public class InputBindingExample {
 

examples/src/main/java/io/dapr/examples/bindings/http/OutputBindingExample.java

@@ -15,7 +15,7 @@ import io.dapr.client.DaprClientBuilder;
  * 2. cd to [repo-root]/examples
  * 3. Run the program:
  * dapr run --app-id outputbinding --port 3006 \
- *   -- mvn exec:java -D exec.mainClass=io.dapr.examples.bindings.http.OutputBindingExample
+ *   -- java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.bindings.http.OutputBindingExample
  */
 public class OutputBindingExample {
 

examples/src/main/java/io/dapr/examples/bindings/http/README.md

@@ -89,7 +89,7 @@ public class InputBindingController {
  Execute the follow script in order to run the Input Binding example:
 ```sh
 cd to [repo-root]/examples
-dapr run --app-id inputbinding --app-port 3000 --port 3005 -- mvn exec:java -D exec.mainClass=io.dapr.examples.bindings.http.InputBindingExample -D exec.args="-p 3000"
+dapr run --app-id inputbinding --app-port 3000 --port 3005 -- java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.bindings.http.InputBindingExample -p 3000
 ```
 
 ### Running the Output binding sample
@@ -123,7 +123,7 @@ Use the follow command to execute the Output Binding example:
 
 ```sh
 cd to [repo-root]/examples
-dapr run --app-id outputbinding --port 3006 -- mvn exec:java -D exec.mainClass=io.dapr.examples.bindings.http.OutputBindingExample
+dapr run --app-id outputbinding --port 3006 -- java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.bindings.http.OutputBindingExample
 ```
 
 Once running, the OutputBindingExample should print the output as follows:

examples/src/main/java/io/dapr/examples/invoke/grpc/HelloWorldClient.java

@@ -13,7 +13,8 @@ import io.dapr.client.domain.Verb;
  * 1. Build and install jars:
  * mvn clean install
  * 2. Send messages to the server:
- * dapr run -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.invoke.grpc.HelloWorldClient
+ * dapr run -- java -jar examples/target/dapr-java-sdk-examples-exec.jar \
+ * io.dapr.examples.invoke.grpc.HelloWorldClient
  */
 public class HelloWorldClient {
 

examples/src/main/java/io/dapr/examples/invoke/grpc/HelloWorldService.java

@@ -30,8 +30,9 @@ import static io.dapr.examples.DaprExamplesProtos.SayResponse;
  * mvn clean install
  * 2. Run in server mode:
  * dapr run --app-id hellogrpc --app-port 5000 --protocol grpc \
- *   -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.invoke.grpc.HelloWorldService \
+ *   -- java -jar examples/target/dapr-java-sdk-examples-exec.jar \
- *   -D exec.args="-p 5000"
+ *   io.dapr.examples.invoke.grpc.HelloWorldService \
+ *   -p 5000
  */
 public class HelloWorldService {
 

examples/src/main/java/io/dapr/examples/invoke/grpc/README.md

@@ -70,7 +70,7 @@ In the `GrpcHelloWorldDaprService` class, the `onInvoke` method is the most impo
 Now run the service code:
 
 ```sh
-dapr run --app-id hellogrpc --app-port 5000 --protocol grpc -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.invoke.grpc.HelloWorldService -D exec.args="-p 5000"
+dapr run --app-id hellogrpc --app-port 5000 --protocol grpc -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.invoke.grpc.HelloWorldService -p 5000
 ```
 
 The `app-id` argument is used to identify this service in Dapr's runtime. The `app-port` determines which port Dapr's runtime should call into this service.  The `protocol` argument informs Dapr which protocol it should use to invoke the application: `grpc` or `http`(default).
@@ -110,7 +110,7 @@ Finally, it will go through in an infinite loop and invoke the `say` method ever
 Finally, open a new command line terminal and run the client code to send some messages.
 
 ```sh
-dapr run -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.invoke.grpc.HelloWorldClient
+dapr run -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.invoke.grpc.HelloWorldClient
 ```
 
 Once the messages are sent, use `CTRL+C` to exit Dapr.

examples/src/main/java/io/dapr/examples/invoke/http/DemoService.java

@@ -16,7 +16,8 @@ import org.apache.commons.cli.Options;
  * mvn clean install
  * 2. Run in server mode:
  * dapr run --app-id invokedemo --app-port 3000 --port 3005 \
- *   -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.invoke.http.DemoService -D exec.args="-p 3000"
+ *   -- java -jar examples/target/dapr-java-sdk-examples-exec.jar \
+ *   io.dapr.examples.invoke.http.DemoService -p 3000
  */
 public class DemoService {
 

examples/src/main/java/io/dapr/examples/invoke/http/InvokeClient.java

@@ -13,8 +13,8 @@ import io.dapr.client.domain.Verb;
  * 1. Build and install jars:
  * mvn clean install
  * 2. Send messages to the server:
- * dapr run --port 3006 -- mvn exec:java -pl=examples \
+ * dapr run --port 3006 -- java -jar examples/target/dapr-java-sdk-examples-exec.jar \
- *   -Dexec.mainClass=io.dapr.examples.invoke.http.InvokeClient -Dexec.args="'message one' 'message two'"
+ *   'message one' 'message two'
  */
 public class InvokeClient {
 

examples/src/main/java/io/dapr/examples/invoke/http/README.md

@@ -89,7 +89,7 @@ public class DemoServiceController {
 Use the follow command to execute the demo service example:
 
 ```sh
-dapr run --app-id invokedemo --app-port 3000 --port 3005 -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.invoke.http.DemoService -D exec.args="-p 3000"
+dapr run --app-id invokedemo --app-port 3000 --port 3005 -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.invoke.http.DemoService -p 3000
 ```
 
 Once running, the ExposerService is now ready to be invoked by Dapr.
@@ -118,7 +118,7 @@ The class knows the app id for the remote application. It uses the the static `D
  
  Execute the follow script in order to run the InvokeClient example, passing two messages for the remote method:
 ```sh
-dapr run --port 3006 -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.invoke.http.InvokeClient -D exec.args="'message one' 'message two'"
+dapr run --port 3006 -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.invoke.http.InvokeClient 'message one' 'message two'
 ```
 Once running, the output should display the messages sent from invoker in the demo service output as follows:
 

examples/src/main/java/io/dapr/examples/pubsub/http/Publisher.java

@@ -16,7 +16,7 @@ import java.util.Collections;
  * mvn clean install
  * 2. Run the program:
  * dapr run --app-id publisher --port 3006 -- \
- *   mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.pubsub.http.Publisher
+ *  java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.pubsub.http.Publisher
  */
 public class Publisher {
 

examples/src/main/java/io/dapr/examples/pubsub/http/README.md

@@ -74,7 +74,7 @@ public class SubscriberController {
 ```
 Execute the follow script in order to run the Subscriber example:
 ```sh
-dapr run --app-id subscriber --app-port 3000 --port 3005 -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.pubsub.http.Subscriber -D exec.args="-p 3000"
+dapr run --app-id subscriber --app-port 3000 --port 3005 -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.pubsub.http.Subscriber -p 3000
 ```
 
 ### Running the publisher
@@ -122,7 +122,7 @@ public class Publisher {
 Use the follow command to execute the Publisher example:
 
 ```sh
-dapr run --app-id publisher --port 3006 -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.pubsub.http.Publisher
+dapr run --app-id publisher --port 3006 -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.pubsub.http.Publisher
 ```
 
 Once running, the Publisher should print the output as follows:

examples/src/main/java/io/dapr/examples/pubsub/http/Subscriber.java

@@ -17,7 +17,7 @@ import org.apache.commons.cli.Options;
  * mvn clean install
  * 2. Run the server:
  * dapr run --app-id subscriber --app-port 3000 --port 3005 -- \
- *   mvn exec:java -pl=examples -Dexec.mainClass=io.dapr.examples.pubsub.http.Subscriber -Dexec.args="-p 3000"
+ *   java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.pubsub.http.Subscriber -p 3000
  */
 public class Subscriber {
 

examples/src/main/java/io/dapr/examples/state/README.md

@@ -62,7 +62,7 @@ The code uses the `DaprClient` created by the `DaprClientBuilder`. Notice that t
 
 Run this example with the following command:
 ```sh
-dapr run --port 3006 -- mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.state.StateClient -D exec.args="'my message'"
+dapr run --port 3006 -- java -jar examples/target/dapr-java-sdk-examples-exec.jar io.dapr.examples.state.StateClient 'my message'
 ```
 Once running, the OutputBindingExample should print the output as follows:
 

examples/src/main/java/io/dapr/examples/state/StateClient.java

@@ -15,7 +15,8 @@ import reactor.core.publisher.Mono;
  * mvn clean install
  * 2. send a message to be saved as state:
  * dapr run --port 3006 -- \
- * mvn exec:java -pl=examples -D exec.mainClass=io.dapr.examples.state.StateClient -D exec.args="'my message'"
+ * java -jar examples/target/dapr-java-sdk-examples-exec.jar \
+ * io.dapr.examples.state.StateClient 'my message'
  */
 public class StateClient {
 

examples/src/main/java/io/dapr/springboot/DaprMainApplication.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) Microsoft Corporation.
+ * Licensed under the MIT License.
+ */
+
+package io.dapr.springboot;
+
+import java.lang.reflect.Method;
+import java.util.Arrays;
+
+/**
+ * Dapr's Main Application to run using fatjar. This class will call the main source provided by user dynamically.
+ */
+public class DaprMainApplication {
+  /**
+   * Calls main method of the class provided by the user.
+   * @param args  Accepts the classname as the first parameter. The rest are passed as argument as args.
+   */
+  public static void main(String[] args) throws Exception {
+    String[] arguments;
+    if (args.length < 1) {
+      throw new IllegalArgumentException("Requires at least one argument - name of the main class");
+    } else {
+      arguments = Arrays.copyOfRange(args, 1, args.length);
+      Class mainClass = Class.forName(args[0]);
+      Method mainMethod = mainClass.getDeclaredMethod("main", String[].class);
+      Object[] methodArgs = new Object[1];
+      methodArgs[0] = arguments;
+      mainMethod.invoke(mainClass, methodArgs);
+
+    }
+  }
+}