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BATCH-768:Updated reference documentation for m1. Also added classes to samples that are necessary for docs.

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lucasward
2008-08-15 20:25:37 +00:00
parent 3c59f6504b
commit 00bd1f4b89
1 changed files with 43 additions and 42 deletions
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85
docs/src/site/docbook/reference/readersAndWriters.xml
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@@ -1951,15 +1951,15 @@
that contains another <classname>ItemReader</classname>. For
example:</para>
<programlisting> public class CompositeItemWriter implements ItemWriter {
<programlisting> public class CompositeItemWriter&lt;T&gt; implements ItemWriter&lt;T&gt; {
ItemWriter itemWriter;
ItemWriter&lt;T&gt; itemWriter;
public CompositeItemWriter(ItemWriter itemWriter) {
public CompositeItemWriter(ItemWriter&lt;T&gt; itemWriter) {
this.itemWriter = itemWriter;
}
public void write(Object item) throws Exception {
public void write(T item) throws Exception {
//Add business logic here
@@ -1990,10 +1990,10 @@
just want to modify the item. For this scenario, Spring Batch provides the
<classname>ItemTransformer</classname> interface:</para>
<programlisting> public interface ItemTransformer {
<programlisting> public interface ItemProcessor&lt;I, O&gt; {
Object transform(Object item) throws Exception;
}</programlisting>
O process(I item) throws Exception;
}</programlisting>
<para>An <classname>ItemTransformer</classname> is very simple, given one
object, transorm it and return another. The object provided may or may not
@@ -2015,7 +2015,7 @@
public Bar(Foo foo) {}
}
public class FooTransformer implements ItemTransformer{
public class FooTransformer implements ItemProcessor{
//Preform simple transformation, convert a Foo to a Barr
public Object transform(Object item) throws Exception {
@@ -2126,7 +2126,7 @@
<classname>BarTransformer</classname> can be 'chained' together to give
the resultant <classname>Foobar</classname>:</para>
<programlisting> CompositeItemTransformer compositeTransformer = new CompositeItemTransformer();
<programlisting> CompositeItemProcessor compositeTransformer = new CompositeItemProcessor();
List itemTransformers = new ArrayList();
itemTransformers.add(new FooTransformer());
itemTransformers.add(new BarTransformer());
@@ -2299,15 +2299,15 @@
basic contract of <classname>ItemReader</classname>,
<methodname>read</methodname>:</para>
<programlisting> public class CustomItemReader implements ItemReader{
<programlisting> public class CustomItemReader&lt;T&gt; implements ItemReader&lt;T&gt;{
List items;
List&lt;T&gt; items;
public CustomItemReader(List items) {
public CustomItemReader(List&lt;T&gt; items) {
this.items = items;
}
public Object read() throws Exception, UnexpectedInputException,
public T read() throws Exception, UnexpectedInputException,
NoWorkFoundException, ParseException {
if (!items.isEmpty()) {
@@ -2326,12 +2326,12 @@
thus satisfying the most basic requirements of an
<classname>ItemReader</classname>, as illustrated below:</para>
<programlisting> List items = new ArrayList();
<programlisting> List&lt;String&gt; items = new ArrayList&lt;String&gt;();
items.add("1");
items.add("2");
items.add("3");
ItemReader itemReader = new CustomItemReader(items);
ItemReader itemReader = new CustomItemReader&lt;String&gt;(items);
assertEquals("1", itemReader.read());
assertEquals("2", itemReader.read());
assertEquals("3", itemReader.read());
@@ -2351,17 +2351,17 @@
empty, but we'll need to add code to them in order to support the
rollback scenario:</para>
<programlisting> public class CustomItemReader implements ItemReader{
<programlisting> public class CustomItemReader&lt;T&gt; implements ItemReader&lt;T&gt;{
List items;
List&lt;T&gt; items;
int currentIndex = 0;
int lastMarkedIndex = 0;
public CustomItemReader(List items) {
public CustomItemReader(List&lt;T&gt; items) {
this.items = items;
}
public Object read() throws Exception, UnexpectedInputException,
public T read() throws Exception, UnexpectedInputException,
NoWorkFoundException, ParseException {
if (currentIndex &lt; items.size()) {
@@ -2434,49 +2434,51 @@
implemented with the <classname>ItemStream</classname>
interface:</para>
<programlisting> public class CustomItemReader implements ItemReader, ItemStream{
<programlisting> public class CustomItemReader&lt;T&gt; implements ItemReader&lt;T&gt;, ItemStream{
List items;
List&lt;T&gt; items;
int currentIndex = 0;
int lastMarkedIndex = 0;
private static String CURRENT_INDEX = "current.index";
private static final String CURRENT_INDEX = "current.index";
public CustomItemReader(List items) {
public CustomItemReader(List&lt;T&gt; items) {
this.items = items;
}
public Object read() throws Exception, UnexpectedInputException,
public T read() throws Exception, UnexpectedInputException,
NoWorkFoundException, ParseException {
if (currentIndex &lt; items.size()) {
return items.get(currentIndex++);
}
return null;
return null;
}
public void mark() throws MarkFailedException {
lastMarkedIndex = currentIndex;
};
}
public void reset() throws ResetFailedException {
currentIndex = lastMarkedIndex;
}
public void open(ExecutionContext executionContext) throws ItemStreamTException {
public void open(ExecutionContext executionContext) throws ItemStreamException {
if(executionContext.containsKey(CURRENT_INDEX)){
currentIndex = new Long(executionContext.getLong(CURRENT_INDEX)).intValue();
}
else{
currentIndex = 0;
lastMarkedIndex = 0;
}
}
}
public void close(ExecutionContext executionContext) throws ItemStreamException {}
public void update(ExecutionContext executionContext) throws ItemStreamException {
executionContext.putLong(CURRENT_INDEX, new Long(currentIndex).longValue());
};
public void close(ExecutionContext executionContext) throws ItemStreamException {}
}</programlisting>
<para>On each call to <classname>ItemStream</classname>
@@ -2494,11 +2496,11 @@
assertEquals("1", itemReader.read());
((ItemStream)itemReader).update(executionContext);
List items = new ArrayList();
List&lt;String&gt; items = new ArrayList&lt;String&gt;();
items.add("1");
items.add("2");
items.add("3");
itemReader = new CustomItemReader(items);
itemReader = new CustomItemReader&lt;String&gt;(items);
((ItemStream)itemReader).open(executionContext);
assertEquals("2", itemReader.read());</programlisting>
@@ -2532,11 +2534,11 @@
example. As with the <classname>ItemReader</classname> example, a List
will be used in order to keep the example as simple as possible:</para>
<programlisting> public class CustomItemWriter implements ItemWriter{
<programlisting> public class CustomItemWriter&lt;T&gt; implements ItemWriter&lt;T&gt;{
List output = new ArrayList();
List&lt;T&gt; output = new ArrayList&lt;T&gt;();
public void write(Object item) throws Exception {
public void write(T item) throws Exception {
output.add(item);
}
@@ -2563,12 +2565,12 @@
<methodname>flush</methodname> and <methodname>clear</methodname>
should be implemented to allow for a buffering solution:</para>
<programlisting> public class CustomItemWriter implements ItemWriter{
<programlisting> public class CustomItemWriter&lt;T&gt; implements ItemWriter&lt;T&gt;{
List output = new ArrayList();
List buffer = new ArrayList();
List&lt;T&gt; output = new ArrayList&lt;T&gt;();
List&lt;T&gt; buffer = new ArrayList&lt;T&gt;();
public void write(Object item) throws Exception {
public void write(T item) throws Exception {
buffer.add(item);
}
@@ -2577,9 +2579,8 @@
}
public void flush() throws FlushFailedException {
for(Iterator it = buffer.iterator(); it.hasNext();){
output.add(it.next());
it.remove();
for(T t:buffer){
output.add(t);
}
}
}</programlisting>