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BATCH-915:MultiResourceItemReader no longer throws ItemStreamExceptions in open except in a restart scenario, the inner class has also been removed.

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lucasward
2009-09-17 23:50:07 +00:00
parent 6272d2844e
commit 2a39ca7a25
2 changed files with 86 additions and 78 deletions
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103
spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/MultiResourceItemReader.java
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@@ -40,14 +40,15 @@ import org.springframework.util.ClassUtils;
* Input resources are ordered using {@link #setComparator(Comparator)} to make
* sure resource ordering is preserved between job runs in restart scenario.
*
* Reset (rollback) capability is implemented by item buffering.
*
*
* @author Robert Kasanicky
* @author Lucas Ward
*/
public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
private static final Log logger = LogFactory.getLog(MultiResourceItemReader.class);
private static final String RESOURCE_KEY = "resourceIndex";
private final ExecutionContextUserSupport executionContextUserSupport = new ExecutionContextUserSupport();
@@ -55,9 +56,9 @@ public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
private Resource[] resources;
private MultiResourceIndex index = new MultiResourceIndex();
private boolean saveState = true;
private int currentResource = -1;
// signals there are no resources to read -> just return null on first read
private boolean noInput;
@@ -85,11 +86,17 @@ public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
if (noInput) {
return null;
}
//If there is no resource, then this is the first item, set the current
//resource to 0 and open the first delegate.
if(currentResource == -1){
currentResource = 0;
delegate.setResource(resources[currentResource]);
delegate.open(new ExecutionContext());
}
T item;
item = readNextItem();
index.incrementItemCount();
return item;
}
@@ -105,14 +112,14 @@ public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
while (item == null) {
index.incrementResourceCount();
currentResource++;
if (index.currentResource >= resources.length) {
if (currentResource >= resources.length) {
return null;
}
delegate.close();
delegate.setResource(resources[index.currentResource]);
delegate.setResource(resources[currentResource]);
delegate.open(new ExecutionContext());
item = delegate.read();
@@ -126,7 +133,6 @@ public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
* and reset instance variable values.
*/
public void close() throws ItemStreamException {
index = new MultiResourceIndex();
delegate.close();
noInput = false;
}
@@ -148,19 +154,13 @@ public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
Arrays.sort(resources, comparator);
index.open(executionContext);
delegate.setResource(resources[index.currentResource]);
delegate.open(new ExecutionContext());
try {
for (int i = 0; i < index.currentItem; i++) {
delegate.read();
}
if (executionContext.containsKey(executionContextUserSupport.getKey(RESOURCE_KEY))) {
currentResource = executionContext.getInt(executionContextUserSupport.getKey(RESOURCE_KEY));
delegate.setResource(resources[currentResource]);
delegate.open(executionContext);
}
catch (Exception e) {
throw new ItemStreamException("Could not restore position on restart", e);
else{
currentResource = -1;
}
}
@@ -169,7 +169,8 @@ public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
*/
public void update(ExecutionContext executionContext) throws ItemStreamException {
if (saveState) {
index.update(executionContext);
executionContext.putInt(executionContextUserSupport.getKey(RESOURCE_KEY), currentResource);
delegate.update(executionContext);
}
}
@@ -207,62 +208,10 @@ public class MultiResourceItemReader<T> implements ItemReader<T>, ItemStream {
}
public Resource getCurrentResource() {
if (index.currentResource >= resources.length) {
if (currentResource >= resources.length) {
return null;
}
return resources[index.currentResource];
}
/**
* Facilitates keeping track of the position within multi-resource input.
*/
private class MultiResourceIndex {
private static final String RESOURCE_KEY = "resourceIndex";
private static final String ITEM_KEY = "itemIndex";
private int currentResource = 0;
private int markedResource = 0;
private int currentItem = 0;
private int markedItem = 0;
public void incrementItemCount() {
currentItem++;
}
public void incrementResourceCount() {
currentResource++;
currentItem = 0;
}
public void mark() {
markedResource = currentResource;
markedItem = currentItem;
}
public void reset() {
currentResource = markedResource;
currentItem = markedItem;
}
public void open(ExecutionContext ctx) {
if (ctx.containsKey(executionContextUserSupport.getKey(RESOURCE_KEY))) {
currentResource = ctx.getInt(executionContextUserSupport.getKey(RESOURCE_KEY));
}
if (ctx.containsKey(executionContextUserSupport.getKey(ITEM_KEY))) {
currentItem = ctx.getInt(executionContextUserSupport.getKey(ITEM_KEY));
}
}
public void update(ExecutionContext ctx) {
ctx.putInt(executionContextUserSupport.getKey(RESOURCE_KEY), index.currentResource);
ctx.putInt(executionContextUserSupport.getKey(ITEM_KEY), index.currentItem);
}
return resources[currentResource];
}
}