IN PROGRESS - issue BATCH-7: Remove transaction synchronization and state management from input/output sources (formerly buffering)

http://jira.springframework.org/browse/BATCH-7

Added ItemStream as base interface for ItemReader/Writer.

spring-batch-samples/src/main/java/org/springframework/batch/sample/dao/FlatFileCustomerCreditWriter.java

@@ -17,7 +17,6 @@
 package org.springframework.batch.sample.dao;
 
 import org.springframework.batch.item.ItemWriter;
-import org.springframework.batch.item.ResourceLifecycle;
 import org.springframework.batch.sample.domain.CustomerCredit;
 import org.springframework.beans.factory.DisposableBean;
 
@@ -56,17 +55,13 @@ public class FlatFileCustomerCreditWriter implements CustomerCreditDao,
 		this.outputSource = outputSource;
 	}
 
-	public void open() {
-		if (outputSource instanceof ResourceLifecycle) {
-			((ResourceLifecycle) outputSource).open();
-		}
+	public void open() throws Exception {
+		outputSource.open();
 		opened = true;
 	}
 
-	public void close() {
-		if (outputSource instanceof ResourceLifecycle) {
-			((ResourceLifecycle) outputSource).close();
-		}
+	public void close() throws Exception {
+		outputSource.close();
 	}
 
 	/*

spring-batch-samples/src/main/java/org/springframework/batch/sample/dao/JdbcGameDao.java

@@ -1,6 +1,10 @@
 package org.springframework.batch.sample.dao;
 
+import java.util.Properties;
+
 import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.StreamContext;
+import org.springframework.batch.item.stream.GenericStreamContext;
 import org.springframework.batch.sample.domain.Game;
 import org.springframework.jdbc.core.support.JdbcDaoSupport;
 import org.springframework.util.Assert;
@@ -34,7 +38,36 @@ public class JdbcGameDao extends JdbcDaoSupport implements ItemWriter {
 		this.getJdbcTemplate().update(INSERT_GAME, args);
 	}
 
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#open()
+	 */
+	public void open() throws Exception {
+		// no-op
+	}
+	
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#close()
+	 */
 	public void close() throws Exception {
+		// no-op
+	}
+
+	/**
+	 * Return empty {@link StreamContext}.
+	 * @see org.springframework.batch.item.ItemStream#getRestartData()
+	 */
+	public StreamContext getRestartData() {
+		return new GenericStreamContext(new Properties());
+	}
+	
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#restoreFrom(org.springframework.batch.item.StreamContext)
+	 */
+	public void restoreFrom(StreamContext data) {
+		
 	}
 
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/dao/JdbcPlayerSummaryDao.java

@@ -1,6 +1,10 @@
 package org.springframework.batch.sample.dao;
 
+import java.util.Properties;
+
 import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.StreamContext;
+import org.springframework.batch.item.stream.GenericStreamContext;
 import org.springframework.batch.sample.domain.PlayerSummary;
 import org.springframework.jdbc.core.support.JdbcDaoSupport;
 import org.springframework.util.Assert;
@@ -28,7 +32,36 @@ public class JdbcPlayerSummaryDao extends JdbcDaoSupport implements ItemWriter {
 		getJdbcTemplate().update(INSERT_SUMMARY, args);
 	}
 
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#open()
+	 */
+	public void open() throws Exception {
+		// no-op
+	}
+	
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#close()
+	 */
 	public void close() throws Exception {
+		// no-op
+	}
+
+	/**
+	 * Return empty {@link StreamContext}.
+	 * @see org.springframework.batch.item.ItemStream#getRestartData()
+	 */
+	public StreamContext getRestartData() {
+		return new GenericStreamContext(new Properties());
+	}
+	
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#restoreFrom(org.springframework.batch.item.StreamContext)
+	 */
+	public void restoreFrom(StreamContext data) {
+		
 	}
 
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/reader/StagingItemReader.java

@@ -5,6 +5,7 @@ import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Properties;
 
 import org.apache.commons.lang.SerializationUtils;
 import org.apache.commons.logging.Log;
@@ -12,7 +13,8 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.batch.execution.scope.StepContext;
 import org.springframework.batch.execution.scope.StepContextAware;
 import org.springframework.batch.item.KeyedItemReader;
-import org.springframework.batch.item.ResourceLifecycle;
+import org.springframework.batch.item.StreamContext;
+import org.springframework.batch.item.stream.GenericStreamContext;
 import org.springframework.batch.repeat.synch.BatchTransactionSynchronizationManager;
 import org.springframework.batch.sample.item.writer.StagingItemWriter;
 import org.springframework.beans.factory.DisposableBean;
@@ -26,7 +28,7 @@ import org.springframework.transaction.support.TransactionSynchronizationAdapter
 import org.springframework.transaction.support.TransactionSynchronizationManager;
 import org.springframework.util.Assert;
 
-public class StagingItemReader extends JdbcDaoSupport implements KeyedItemReader, ResourceLifecycle, DisposableBean,
+public class StagingItemReader extends JdbcDaoSupport implements KeyedItemReader, DisposableBean,
 		StepContextAware {
 
 	// Key for buffer in transaction synchronization manager
@@ -250,5 +252,21 @@ public class StagingItemReader extends JdbcDaoSupport implements KeyedItemReader
 			return "list=" + list + "; iter.hasNext()=" + iter.hasNext();
 		}
 	}
+	
+	/**
+	 * Return empty {@link StreamContext}.
+	 * @see org.springframework.batch.item.ItemStream#getRestartData()
+	 */
+	public StreamContext getRestartData() {
+		return new GenericStreamContext(new Properties());
+	}
+	
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#restoreFrom(org.springframework.batch.item.StreamContext)
+	 */
+	public void restoreFrom(StreamContext data) {
+		
+	}
 
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/writer/CustomerCreditIncreaseWriter.java

@@ -3,6 +3,7 @@ package org.springframework.batch.sample.item.writer;
 import java.math.BigDecimal;
 
 import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.writer.AbstractItemWriter;
 import org.springframework.batch.sample.dao.CustomerCreditDao;
 import org.springframework.batch.sample.domain.CustomerCredit;
 
@@ -11,7 +12,7 @@ import org.springframework.batch.sample.domain.CustomerCredit;
  * 
  * @author Robert Kasanicky
  */
-public class CustomerCreditIncreaseWriter implements ItemWriter {
+public class CustomerCreditIncreaseWriter extends AbstractItemWriter implements ItemWriter {
 
 	public static final BigDecimal FIXED_AMOUNT = new BigDecimal(1000);
 	
@@ -34,6 +35,9 @@ public class CustomerCreditIncreaseWriter implements ItemWriter {
 		customerCreditDao.writeCredit(customerCredit);
 	}
 
+	public void open() throws Exception {
+	}
+
 	public void close() throws Exception {
 	}
 

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/writer/CustomerCreditUpdateWriter.java

@@ -17,12 +17,13 @@
 package org.springframework.batch.sample.item.writer;
 
 import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.writer.AbstractItemWriter;
 import org.springframework.batch.sample.dao.CustomerCreditDao;
 import org.springframework.batch.sample.domain.CustomerCredit;
 
 
 
-public class CustomerCreditUpdateWriter implements ItemWriter {
+public class CustomerCreditUpdateWriter extends AbstractItemWriter implements ItemWriter {
     private double creditFilter = 800;
     private CustomerCreditDao dao;
 

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/writer/CustomerUpdateWriter.java

@@ -17,6 +17,7 @@
 package org.springframework.batch.sample.item.writer;
 
 import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.writer.AbstractItemWriter;
 import org.springframework.batch.sample.dao.JdbcCustomerDebitWriter;
 import org.springframework.batch.sample.domain.CustomerDebit;
 import org.springframework.batch.sample.domain.Trade;
@@ -27,7 +28,7 @@ import org.springframework.batch.sample.domain.Trade;
  * 
  * @author Robert Kasanicky
  */
-public class CustomerUpdateWriter implements ItemWriter {
+public class CustomerUpdateWriter extends AbstractItemWriter implements ItemWriter {
     private JdbcCustomerDebitWriter dao;
 
     public void write(Object data) {
@@ -42,9 +43,6 @@ public class CustomerUpdateWriter implements ItemWriter {
         this.dao = outputSource;
     }
 
-	public void close() {
-	}
-
 	public void init() {
 	}
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/writer/DummyItemWriter.java

@@ -15,19 +15,16 @@
  */
 package org.springframework.batch.sample.item.writer;
 
-import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.writer.AbstractItemWriter;
 
 /**
  * @author Dave Syer
  *
  */
-public class DummyItemWriter implements ItemWriter {
+public class DummyItemWriter extends AbstractItemWriter  {
 
 	public void write(Object item) throws Exception {
 		// NO-OP
 	}
 
-	public void close() throws Exception {
-	}
-
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/writer/PersonWriter.java

@@ -18,12 +18,12 @@ package org.springframework.batch.sample.item.writer;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.writer.AbstractItemWriter;
 import org.springframework.batch.sample.domain.Person;
 
 
 
-public class PersonWriter implements ItemWriter {
+public class PersonWriter extends AbstractItemWriter  {
     private static Log log = LogFactory.getLog(PersonWriter.class);
  
     public void write(Object data) {
@@ -36,9 +36,6 @@ public class PersonWriter implements ItemWriter {
         log.debug("Processing: " + data);
     }
 
-	public void close() {
-	}
-
 	public void init() {
 	}
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/writer/PlayerItemWriter.java

@@ -1,10 +1,10 @@
 package org.springframework.batch.sample.item.writer;
 
-import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.writer.AbstractItemWriter;
 import org.springframework.batch.sample.dao.PlayerDao;
 import org.springframework.batch.sample.domain.Player;
 
-public class PlayerItemWriter implements ItemWriter {
+public class PlayerItemWriter extends AbstractItemWriter {
 
 	PlayerDao playerDao;
 	
@@ -16,6 +16,4 @@ public class PlayerItemWriter implements ItemWriter {
 		this.playerDao = playerDao;
 	}
 
-	public void close() throws Exception {
-	}
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/writer/StagingItemWriter.java

@@ -2,11 +2,14 @@ package org.springframework.batch.sample.item.writer;
 
 import java.io.Serializable;
 import java.sql.Types;
+import java.util.Properties;
 
 import org.apache.commons.lang.SerializationUtils;
 import org.springframework.batch.execution.scope.StepContext;
 import org.springframework.batch.execution.scope.StepContextAware;
 import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.StreamContext;
+import org.springframework.batch.item.stream.GenericStreamContext;
 import org.springframework.jdbc.core.support.JdbcDaoSupport;
 import org.springframework.jdbc.support.incrementer.DataFieldMaxValueIncrementer;
 import org.springframework.util.Assert;
@@ -73,7 +76,37 @@ public class StagingItemWriter extends JdbcDaoSupport implements
 						new int[] { Types.BIGINT, Types.BIGINT, Types.BLOB, Types.CHAR});
 	}
 
+
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#open()
+	 */
+	public void open() throws Exception {
+		// no-op
+	}
+	
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#close()
+	 */
 	public void close() throws Exception {
+		// no-op
+	}
+
+	/**
+	 * Return empty {@link StreamContext}.
+	 * @see org.springframework.batch.item.ItemStream#getRestartData()
+	 */
+	public StreamContext getRestartData() {
+		return new GenericStreamContext(new Properties());
+	}
+	
+	/**
+	 * Do nothing.
+	 * @see org.springframework.batch.item.ItemStream#restoreFrom(org.springframework.batch.item.StreamContext)
+	 */
+	public void restoreFrom(StreamContext data) {
+		
 	}
 
 }

spring-batch-samples/src/main/java/org/springframework/batch/sample/item/writer/TradeWriter.java

@@ -18,13 +18,13 @@ package org.springframework.batch.sample.item.writer;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.writer.AbstractItemWriter;
 import org.springframework.batch.sample.dao.TradeDao;
 import org.springframework.batch.sample.domain.Trade;
 
 
 
-public class TradeWriter implements ItemWriter {
+public class TradeWriter extends AbstractItemWriter {
     private static Log log = LogFactory.getLog(TradeWriter.class);
     private TradeDao dao;