Streamline and refactor the azure and the azure-web adapters.

- Add SCF/Azure Gradle sample and docs.
- Move the function-azure-di-samples into standalone projects.
 - Apply the name convetion and project structure for the SCF adaptes.
   E.g.  function-sample-azure-XXX projects under the spring-cloud-function-samples root.
 - Remove the redudant samples.
 - Improve the samples docs and the Adapter generic docs.
- Streamline docs.
- Add azure web adapter sample and README.
- Add Spring Azure Functions banner for azure and azure web adapters.
- azure-web adapter fixes:
  - Fix issues in serverles-web ProxyHttpServletResponse implementation.
  - Remove the custom FunctionClassUtils utils in favor of scf-context/util/FunctionClassUtils.
- Remove redundant files.
- Add FunctionInvoker deprecation annotations.
- Extend the time trigger sample with Retry policies example.

spring-cloud-function-samples/function-sample-azure-time-trigger/src/main/java/com/example/azure/di/timetriggerdemo/TimeTriggerDemoApplication.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2021-2022 the original author or 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.
+ */
+
+package com.example.azure.di.timetriggerdemo;
+
+import java.util.function.Consumer;
+
+import com.microsoft.azure.functions.ExecutionContext;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.messaging.Message;
+
+@SpringBootApplication
+public class TimeTriggerDemoApplication {
+
+	private static Log logger = LogFactory.getLog(TimeTriggerDemoApplication.class);
+
+	public static void main(String[] args) {
+		SpringApplication.run(TimeTriggerDemoApplication.class, args);
+	}
+
+	@Bean
+	public Consumer<Message<String>> uppercase() {
+		return message -> {
+			String timeInfo = message.getPayload();
+			String value = timeInfo.toUpperCase();
+
+			logger.info("Timer is triggered with TimeInfo: " + value);
+
+			// (Optionally) access and use the Azure function context.
+			ExecutionContext context = (ExecutionContext) message.getHeaders().get(UppercaseHandler.EXECUTION_CONTEXT);
+			context.getLogger().info("Execution Context Log - TimeInfo: " + value);
+
+			// No response.
+		};
+	}
+
+}

spring-cloud-function-samples/function-sample-azure-time-trigger/src/main/java/com/example/azure/di/timetriggerdemo/UppercaseHandler.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2021-2022 the original author or 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.
+ */
+
+package com.example.azure.di.timetriggerdemo;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
+
+import com.microsoft.azure.functions.ExecutionContext;
+import com.microsoft.azure.functions.annotation.ExponentialBackoffRetry;
+import com.microsoft.azure.functions.annotation.FixedDelayRetry;
+import com.microsoft.azure.functions.annotation.FunctionName;
+import com.microsoft.azure.functions.annotation.TimerTrigger;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.support.MessageBuilder;
+import org.springframework.stereotype.Component;
+
+@Component
+public class UppercaseHandler {
+
+    public static String EXECUTION_CONTEXT = "executionContext";
+
+    private static AtomicInteger count = new AtomicInteger();
+
+    @Autowired
+    private Consumer<Message<String>> uppercase;
+
+    @FunctionName("uppercase")
+    @FixedDelayRetry(maxRetryCount = 4, delayInterval = "00:00:10")
+    public void execute(@TimerTrigger(name = "keepAliveTrigger", schedule = "0 */1 * * * *") String timerInfo,
+            ExecutionContext context) {
+
+        Message<String> message = MessageBuilder
+                .withPayload(timerInfo)
+                .setHeader(EXECUTION_CONTEXT, context)
+                .build();
+
+        this.uppercase.accept(message);
+    }
+
+    @FunctionName("uppercaseExpRetry")
+    @ExponentialBackoffRetry(maxRetryCount = 4, maximumInterval = "00:15:00", minimumInterval = "00:00:03")
+    public void executeExpRetry(@TimerTrigger(name = "keepAliveTrigger", schedule = "*/10 * * * * *") String timerInfo,
+            ExecutionContext context) {
+
+        if (count.incrementAndGet() < 3) {
+            context.getLogger().info("EMULATE ERROR# " + count.get());
+            throw new IllegalStateException("Emulated ERROR# " + count.get());
+        }
+
+        context.getLogger().info("ERRORLESS EXECUTION");
+
+        Message<String> message = MessageBuilder
+                .withPayload(timerInfo)
+                .setHeader(EXECUTION_CONTEXT, context)
+                .build();
+
+        this.uppercase.accept(message);
+    }
+}

spring-cloud-function-samples/function-sample-azure-time-trigger/src/main/resources/application.properties

@@ -0,0 +1 @@
+

spring-cloud-function-samples/function-sample-azure-time-trigger/src/main/resources/host.json

@@ -0,0 +1,7 @@
+{
+    "version": "2.0",
+    "extensionBundle": {
+        "id": "Microsoft.Azure.Functions.ExtensionBundle",
+        "version": "[3.*, 4.0.0)"
+    }
+}

spring-cloud-function-samples/function-sample-azure-time-trigger/src/main/resources/local.settings.json

@@ -0,0 +1,8 @@
+{
+	"IsEncrypted": false,
+	"Values": {
+		"AzureWebJobsStorage": "UseDevelopmentStorage=true",
+		"AzureWebJobsDashboard": "",
+		"FUNCTIONS_WORKER_RUNTIME": "java"
+	}
+}

spring-cloud-function-samples/function-sample-azure-time-trigger/src/test/java/com/example/azure/di/timetriggerdemo/TimetriggerDemoApplicationTests.java

@@ -0,0 +1,13 @@
+package com.example.azure.di.timetriggerdemo;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class TimetriggerDemoApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}