Changed default ExecutionContext serialization mechanism

The current default for serializing the ExecutionContext is via XStream
using Jettison's driver.  However, recent updates to Jettison make it
incompatible with XStream with no progress on a fix.  Because of this,
and to encourage the use of well supported library combinations, the
default ExecutionContext serialization mechanism for Spring Batch has
been switched to Jackson (via the
Jackson2ExecutionContextStringSerializer).  This commit also depricates
the XStreamExecutionContextStringSerializer for removal at a later date.
However, it is still available for users that require that during a
migration.

Resolves BATCH-2575

Author: mminella

spring-batch-core/src/main/java/org/springframework/batch/core/explore/support/JobExplorerFactoryBean.java

@@ -16,10 +16,13 @@
 
 package org.springframework.batch.core.explore.support;
 
+import javax.sql.DataSource;
+
 import org.springframework.batch.core.explore.JobExplorer;
 import org.springframework.batch.core.repository.ExecutionContextSerializer;
 import org.springframework.batch.core.repository.dao.AbstractJdbcBatchMetadataDao;
 import org.springframework.batch.core.repository.dao.ExecutionContextDao;
+import org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer;
 import org.springframework.batch.core.repository.dao.JdbcExecutionContextDao;
 import org.springframework.batch.core.repository.dao.JdbcJobExecutionDao;
 import org.springframework.batch.core.repository.dao.JdbcJobInstanceDao;
@@ -38,8 +41,6 @@
 import org.springframework.jdbc.support.lob.LobHandler;
 import org.springframework.util.Assert;
 
-import javax.sql.DataSource;
-
 /**
  * A {@link FactoryBean} that automates the creation of a
  * {@link SimpleJobExplorer} using JDBC DAO implementations. Requires the user
@@ -127,10 +128,7 @@ public void afterPropertiesSet() throws Exception {
 		}	
 
 		if(serializer == null) {
-			XStreamExecutionContextStringSerializer defaultSerializer = new XStreamExecutionContextStringSerializer();
-			defaultSerializer.afterPropertiesSet();
-
-			serializer = defaultSerializer;
+			serializer = new Jackson2ExecutionContextStringSerializer();
 		}
 	}
 

spring-batch-core/src/main/java/org/springframework/batch/core/jsr/partition/JsrPartitionHandler.java

@@ -303,7 +303,10 @@ private Set<StepExecution> applyPartitionPlan(StepExecution stepExecution,
 			throw new IllegalArgumentException("Either a number of threads or partitions are required");
 		}
 
-		stepExecution.getExecutionContext().put("partitionPlanState", new PartitionPlanState(plan));
+		PartitionPlanState partitionPlanState = new PartitionPlanState();
+		partitionPlanState.setPartitionPlan(plan);
+
+		stepExecution.getExecutionContext().put("partitionPlanState", partitionPlanState);
 
 		stepSplitter = new JsrStepExecutionSplitter(jobRepository, allowStartIfComplete, stepExecution.getStepName(), restoreState);
 		partitionStepExecutions = stepSplitter.split(stepExecution, plan.getPartitions());
@@ -416,6 +419,15 @@ public PartitionPlanState(PartitionPlan plan) {
 			threads = plan.getThreads();
 		}
 
+		public PartitionPlanState() {
+		}
+
+		public void setPartitionPlan(PartitionPlan plan) {
+			this.partitionProperties = plan.getPartitionProperties();
+			this.partitions = plan.getPartitions();
+			this.threads = plan.getThreads();
+		}
+
 		/* (non-Javadoc)
 		 * @see javax.batch.api.partition.PartitionPlan#getPartitionProperties()
 		 */

spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/XStreamExecutionContextStringSerializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2013 the original author or authors.
+ * Copyright 2006-2017 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.
@@ -23,24 +23,27 @@
 import java.io.OutputStream;
 import java.util.Map;
 
+import com.thoughtworks.xstream.XStream;
+import com.thoughtworks.xstream.converters.reflection.ReflectionProvider;
+import com.thoughtworks.xstream.io.HierarchicalStreamDriver;
+import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
+
 import org.springframework.batch.core.repository.ExecutionContextSerializer;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.core.serializer.Deserializer;
 import org.springframework.core.serializer.Serializer;
 import org.springframework.util.Assert;
 
-import com.thoughtworks.xstream.XStream;
-import com.thoughtworks.xstream.converters.reflection.ReflectionProvider;
-import com.thoughtworks.xstream.io.HierarchicalStreamDriver;
-import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
-
 /**
  * Implementation that uses XStream and Jettison to provide serialization.
  *
  * @author Thomas Risberg
  * @author Michael Minella
  * @since 2.0
  * @see ExecutionContextSerializer
+ * @deprecated Due to the incompattabilities between current Jettison versions and XStream
+ * 		versions, this serializer is depricated in favor of
+ * 		{@link Jackson2ExecutionContextStringSerializer}
  */
 public class XStreamExecutionContextStringSerializer implements ExecutionContextSerializer, InitializingBean {
 

spring-batch-core/src/main/java/org/springframework/batch/core/repository/support/JobRepositoryFactoryBean.java

@@ -26,14 +26,14 @@
 import org.springframework.batch.core.repository.ExecutionContextSerializer;
 import org.springframework.batch.core.repository.dao.AbstractJdbcBatchMetadataDao;
 import org.springframework.batch.core.repository.dao.ExecutionContextDao;
+import org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer;
 import org.springframework.batch.core.repository.dao.JdbcExecutionContextDao;
 import org.springframework.batch.core.repository.dao.JdbcJobExecutionDao;
 import org.springframework.batch.core.repository.dao.JdbcJobInstanceDao;
 import org.springframework.batch.core.repository.dao.JdbcStepExecutionDao;
 import org.springframework.batch.core.repository.dao.JobExecutionDao;
 import org.springframework.batch.core.repository.dao.JobInstanceDao;
 import org.springframework.batch.core.repository.dao.StepExecutionDao;
-import org.springframework.batch.core.repository.dao.XStreamExecutionContextStringSerializer;
 import org.springframework.batch.item.database.support.DataFieldMaxValueIncrementerFactory;
 import org.springframework.batch.item.database.support.DefaultDataFieldMaxValueIncrementerFactory;
 import org.springframework.batch.support.DatabaseType;
@@ -90,7 +90,7 @@ public void setClobType(int type) {
 
 	/**
 	 * A custom implementation of the {@link ExecutionContextSerializer}.
-	 * The default, if not injected, is the {@link XStreamExecutionContextStringSerializer}.
+	 * The default, if not injected, is the {@link Jackson2ExecutionContextStringSerializer}.
 	 *
 	 * @param serializer used to serialize/deserialize {@link org.springframework.batch.item.ExecutionContext}
 	 * @see ExecutionContextSerializer
@@ -189,8 +189,7 @@ public void afterPropertiesSet() throws Exception {
 		}
 
 		if(serializer == null) {
-			XStreamExecutionContextStringSerializer defaultSerializer = new XStreamExecutionContextStringSerializer();
-			defaultSerializer.afterPropertiesSet();
+			Jackson2ExecutionContextStringSerializer defaultSerializer = new Jackson2ExecutionContextStringSerializer();
 
 			serializer = defaultSerializer;
 		}

spring-batch-core/src/test/java/org/springframework/batch/core/repository/support/JobRepositoryFactoryBeanTests.java

@@ -29,7 +29,7 @@
 import org.springframework.batch.core.repository.ExecutionContextSerializer;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.repository.dao.DefaultExecutionContextSerializer;
-import org.springframework.batch.core.repository.dao.XStreamExecutionContextStringSerializer;
+import org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer;
 import org.springframework.batch.item.database.support.DataFieldMaxValueIncrementerFactory;
 import org.springframework.core.serializer.Serializer;
 import org.springframework.dao.DataAccessException;
@@ -153,7 +153,7 @@ public void tesDefaultSerializer() throws Exception {
 
 		factory.afterPropertiesSet();
 		Serializer<Map<String, Object>> serializer = (Serializer<Map<String,Object>>) ReflectionTestUtils.getField(factory, "serializer");
-		assertTrue(serializer instanceof XStreamExecutionContextStringSerializer);
+		assertTrue(serializer instanceof Jackson2ExecutionContextStringSerializer);
 	}
 
 	@Test