Create the DeployerPartitionHandler and related

DeployerStepExecutionHandler

Created a PartitionHandler that delegates to a TaskLauncher from Spring
Cloud Deployer to execute workers.

Resolves spring-cloud/spring-cloud-task#109

Updates per code review

spring-cloud-task-samples/partitioned-batch-job/src/main/java/io/spring/JobConfiguration.java

@@ -0,0 +1,173 @@
+/*
+ * Copyright 2016 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 java.util.HashMap;
+import java.util.Map;
+import javax.sql.DataSource;
+
+import org.springframework.batch.core.Job;
+import org.springframework.batch.core.Step;
+import org.springframework.batch.core.StepContribution;
+import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
+import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
+import org.springframework.batch.core.configuration.annotation.StepScope;
+import org.springframework.batch.core.explore.JobExplorer;
+import org.springframework.batch.core.explore.support.JobExplorerFactoryBean;
+import org.springframework.batch.core.explore.support.SimpleJobExplorer;
+import org.springframework.batch.core.partition.PartitionHandler;
+import org.springframework.batch.core.partition.support.Partitioner;
+import org.springframework.batch.core.repository.JobRepository;
+import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.core.step.tasklet.Tasklet;
+import org.springframework.batch.item.ExecutionContext;
+import org.springframework.batch.repeat.RepeatStatus;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.cloud.deployer.resource.maven.MavenResource;
+import org.springframework.cloud.deployer.spi.local.LocalDeployerProperties;
+import org.springframework.cloud.deployer.spi.local.LocalTaskLauncher;
+import org.springframework.cloud.deployer.spi.task.TaskLauncher;
+import org.springframework.cloud.task.batch.partition.DeployerPartitionHandler;
+import org.springframework.cloud.task.batch.partition.DeployerStepExecutionHandler;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+
+/**
+ * @author Michael Minella
+ */
+@Configuration
+public class JobConfiguration {
+
+	@Autowired
+	public JobBuilderFactory jobBuilderFactory;
+
+	@Autowired
+	public StepBuilderFactory stepBuilderFactory;
+
+	@Autowired
+	public DataSource dataSource;
+
+	@Autowired
+	public JobRepository jobRepository;
+
+	@Autowired
+	private ConfigurableApplicationContext context;
+
+	private static final int GRID_SIZE = 4;
+
+	@Bean
+	public JobExplorerFactoryBean jobExplorer() {
+		JobExplorerFactoryBean jobExplorerFactoryBean = new JobExplorerFactoryBean();
+
+		jobExplorerFactoryBean.setDataSource(this.dataSource);
+
+		return jobExplorerFactoryBean;
+	}
+
+	@Bean
+	public TaskLauncher taskLauncher() {
+		LocalDeployerProperties localDeployerProperties = new LocalDeployerProperties();
+
+		localDeployerProperties.setDeleteFilesOnExit(false);
+
+		return new LocalTaskLauncher(localDeployerProperties);
+	}
+
+	@Bean
+	public PartitionHandler partitionHandler(TaskLauncher taskLauncher, JobExplorer jobExplorer) throws Exception {
+		MavenResource resource = MavenResource.parse("io.spring.cloud:partitioned-batch-job:1.0.0.BUILD-SNAPSHOT");
+
+		DeployerPartitionHandler partitionHandler = new DeployerPartitionHandler(taskLauncher, jobExplorer, resource, "workerStep");
+
+		Map<String, String> environmentProperties = new HashMap<>();
+		environmentProperties.put("spring.profiles.active", "worker");
+
+		partitionHandler.setEnvironmentProperties(environmentProperties);
+		partitionHandler.setMaxWorkers(2);
+
+		return partitionHandler;
+	}
+
+	@Bean
+	public Partitioner partitioner() {
+		return new Partitioner() {
+			@Override
+			public Map<String, ExecutionContext> partition(int gridSize) {
+
+				Map<String, ExecutionContext> partitions = new HashMap<>(gridSize);
+
+				for(int i = 0; i < GRID_SIZE; i++) {
+					ExecutionContext context1 = new ExecutionContext();
+					context1.put("partitionNumber", i);
+
+					partitions.put("partition" + i, context1);
+				}
+
+				return partitions;
+			}
+		};
+	}
+
+	@Bean
+	@Profile("worker")
+	public DeployerStepExecutionHandler stepExecutionHandler(JobExplorer jobExplorer) {
+		DeployerStepExecutionHandler handler = new DeployerStepExecutionHandler(this.context, jobExplorer, this.jobRepository);
+
+		return handler;
+	}
+
+	@Bean
+	@StepScope
+	public Tasklet workerTasklet(
+			final @Value("#{stepExecutionContext['partitionNumber']}")Integer partitionNumber) {
+
+		return new Tasklet() {
+			@Override
+			public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {
+				System.out.println("This tasklet ran partition: " + partitionNumber);
+
+				return RepeatStatus.FINISHED;
+			}
+		};
+	}
+
+	@Bean
+	public Step step1(PartitionHandler partitionHandler) throws Exception {
+		return stepBuilderFactory.get("step1")
+				.partitioner(workerStep().getName(), partitioner())
+				.step(workerStep())
+				.partitionHandler(partitionHandler)
+				.build();
+	}
+
+	@Bean
+	public Step workerStep() {
+		return stepBuilderFactory.get("workerStep")
+				.tasklet(workerTasklet(null))
+				.build();
+	}
+
+	@Bean
+	@Profile("master")
+	public Job job(PartitionHandler partitionHandler) throws Exception {
+		return jobBuilderFactory.get("job")
+				.start(step1(partitionHandler))
+				.build();
+	}
+}