Added a sample that illustrates using multiple DataSources

This PR adds a sample that illustrates the use of multiple DataSources
in a single Spring Cloud Task application.

Resolves #413

Updated based on code review

spring-cloud-task-samples/multiple-datasources/src/main/java/io/spring/MultipleDataSourcesApplication.java

@@ -0,0 +1,35 @@
+/*
+ *  Copyright 2018 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
+ *
+ *          http://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 io.spring;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.task.configuration.EnableTask;
+
+
+/**
+ * @author Michael Minella
+ */
+@SpringBootApplication
+@EnableTask
+public class MultipleDataSourcesApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(MultipleDataSourcesApplication.class, args);
+	}
+
+}

spring-cloud-task-samples/multiple-datasources/src/main/java/io/spring/configuration/CustomTaskConfigurer.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2018 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
+ *
+ *      http://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 io.spring.configuration;
+
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.cloud.task.configuration.DefaultTaskConfigurer;
+import org.springframework.stereotype.Component;
+
+/**
+ * @author Michael Minella
+ */
+@Component
+public class CustomTaskConfigurer extends DefaultTaskConfigurer {
+
+	@Autowired
+	public CustomTaskConfigurer(@Qualifier("secondDataSource") DataSource dataSource) {
+		super(dataSource);
+	}
+}

spring-cloud-task-samples/multiple-datasources/src/main/java/io/spring/configuration/DataSourceConfiguration.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2018 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
+ *
+ *      http://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 io.spring.configuration;
+
+import javax.sql.DataSource;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;
+
+/**
+ * @author Michael Minella
+ */
+@Configuration
+public class DataSourceConfiguration {
+
+	@Bean
+	public DataSource dataSource() {
+		return new EmbeddedDatabaseBuilder()
+				.setType(EmbeddedDatabaseType.HSQL)
+				.build();
+	}
+
+	@Bean
+	public DataSource secondDataSource() {
+		return new EmbeddedDatabaseBuilder()
+				.setType(EmbeddedDatabaseType.H2)
+				.build();
+	}
+}

spring-cloud-task-samples/multiple-datasources/src/main/java/io/spring/task/SampleCommandLineRunner.java

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+/*
+ * Copyright 2018 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
+ *
+ *      http://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 io.spring.task;
+
+import java.util.List;
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.stereotype.Component;
+
+/**
+ * @author Michael Minella
+ */
+@Component
+public class SampleCommandLineRunner implements CommandLineRunner {
+
+	private List<DataSource> dataSources;
+
+	@Autowired
+	public SampleCommandLineRunner(List<DataSource> dataSources) {
+		this.dataSources = dataSources;
+	}
+
+	@Override
+	public void run(String... args) throws Exception {
+		System.out.println("There are " + dataSources.size() +
+				" DataSources within this application");
+	}
+}