<AspireDataSet>
<!-- A set of key value pairs at the root level -->
<key1>val1</key1>
<key2>val2</key2>
<!-- A set of named loops -->
<loop name="loop">
</loop>
<loop name="loop2">
</loop>
</AspireDataSet>
Inner loop further expanded
<loop name="loopname">
<row>
<!-- a set of key value pairs -->
<key1>val1</key1>
<key2>val2</key2>
<!-- a set of named loops -->
<loop name="loopname1">
</loop>
<!-- a set of named loops -->
<loop name="loopname2">
</loop>
</row>
<row>
</row>
</loop>
import com.ai.htmlgen.*;
import com.ai.common.TransformException;
import Java.io.*;
import com.ai.data.*;
// above code removed for clarity
public static void staticTransform(ihds data, PrintWriter out)
throws TransformException
{
try
{
writeALoop("MainData",data,out,"");
}
catch(DataException x)
{
throw new TransformException(
"Error: DebugTextTransform: Data Exception",x);
}
}
/**********************************************************
* A recursive function to write out a loop worth of ihds
**********************************************************
*/
private static void writeALoop(
String loopname, ihds data, PrintWriter out, String is)
throws DataException
{
println(out,is, ">> Writing data for loop:" + loopname);
// write metadata
IMetaData m = data.getMetaData();
IIterator columns = m.getIterator();
StringBuffer colBuffer = new StringBuffer();
for(columns.moveToFirst();!columns.isAtTheEnd();columns.moveToNext())
{
String columnName = (String)columns.getCurrentElement();
colBuffer.append(columnName).append("|");
}
println(out,is,colBuffer.toString());
//write individual rows
for(data.moveToFirst();!data.isAtTheEnd();data.moveToNext())
{
StringBuffer rowBuffer = new StringBuffer();
for(columns.moveToFirst();!columns.isAtTheEnd();columns.moveToNext())
{
String columnName = (String)columns.getCurrentElement();
rowBuffer.append(data.getValue(columnName));
rowBuffer.append("|");
}
println(out,is,rowBuffer.toString());
// recursive call to print children
IIterator children = data.getChildNames();
for(children.moveToFirst();!children.isAtTheEnd();children.moveToNext())
{
// for each child
String childName = (String)children.getCurrentElement();
ihds child = data.getChild(childName);
writeALoop(childName,child,out,is + "\t");
}
}
println(out,is,">> Writing data for loop:" + loopname + " is complete");
}
private static void println(PrintWriter out, String indentationString,
String line)
{
out.print(indentationString);
out.print(line);
out.print("\n");
}
// code removed for clarity
###################################
# ihdsTest data definition: section1
###################################
request.ihdsTest.className=com.ai.htmlgen.DBHashTableFormHandler1
request.ihdsTest.loopNames=loop1,loop2
#section1 - main key value pairs
request.ihdsTest.mainDataRequest.classname=com.ai.db.DBRequestExecutor2
request.ihdsTest.mainDataRequest.db=my-database
request.ihdsTest.mainDataRequest.stmt=some-select
#section2 - loop1
request.ihdsTest.loop1.class_request.className=com.ai.htmlgen.GenericTableHandler6
request.ihdsTest.loop1.loopNames=loop11
request.ihdsTest.loop1.query_request.className=com.ai.data.RowFileReader
request.ihdsTest.loop1.query_request.filename=aspire:\\samples
\\pop-table-tags\\properties\\pop-table.data
#section3 - loop2
request.ihdsTest.loop2.class_request.className=com.ai.htmlgen.GenericTableHandler6
request.ihdsTest.loop2.loopNames=loop11
request.ihdsTest.loop2.query_request.className=com.ai.data.RowFileReader
request.ihdsTest.loop2.query_request.filename=aspire:\\samples
\\pop-table-tags\\properties\\pop-table.data
#section3 - subloop to loop1
request.loop11.class_request.classname=com.ai.htmlgen.GenericTableHandler6
request.loop11.query_request.classname=com.ai.data.RowFileReader
request.loop11.query_request.filename=aspire:\\samples\\pop-table-tags
\\properties\\pop-table.data
package com.ai.htmlgen;
import com.ai.data.*;
/**
* Represents a Hierarchical Data Set.
* An hds is a collection of rows.
* You can step through the rows using ILoopForwardIterator
* You can find out about the columns via IMetaData.
* An hds is also a collection loops originated using the current row.
*/
public interface ihds extends ILoopForwardIterator
{
/**
* Returns the parent if available
* Returns null if there is no parent
*/
public ihds getParent() throws DataException;
/**
* For the current row return a set of
* child loop names. ILoopForwardIteraor determines
* what the current row is.
*
* @see ILoopForwardIterator
*/
public IIterator getChildNames() throws DataException;
/**
* Given a child name return the child Java object
* represented by ihds again
*/
public ihds getChild(String childName) throws DataException;
/**
* returns a column that is similar to SUM, AVG etc of a
* set of rows that are children to this row.
*/
public String getAggregateValue(String keyname) throws DataException;
/**
* Returns the column names of this loop or table.
* @see IMetaData
*/
public IMetaData getMetaData() throws DataException;
/**
* Releases any resources that may be held by this loop of data
* or table.
*/
public void close() throws DataException;
}
package com.ai.htmlgen;
import com.ai.data.*;
public interface ILoopForwardIterator
{
/**
* getValue from the current row matching the key
*/
public String getValue(final String key);
public void moveToFirst() throws DataException;
public void moveToNext() throws DataException;
public boolean isAtTheEnd() throws DataException;
}
package com.ai.data;
public interface IMetaData
{
public IIterator getIterator();
public int getColumnCount();
public int getIndex(final String attributeName)
throws FieldNameNotFoundException;
}
1. Using Hierarchical Data Sets with Aspire and Tomcat, at OnJava.com
2. Use Aspire and Tomcat to retrieve XML declaratively from any relational database
3. Code Examples for relational data sets