I am having some problems using JXPath with Maps and variables.
I have one or more maps that I add as variables to a global context.
When I retrieve a value from a map containing repeating data using a
hard-coded index in the expression, it works OK as follows:
Iterator iter = (Iterator)context.iterate("$map/dataMap/Foo/Bar[3]");
If I replace the hard-coded index value with a simple Integer-type
variable,
it also works:
context.getVariables.declareVariable("index", new Integer(3));
Iterator iter = (Iterator)context.iterate("$map/dataMap/Foo/Bar
[$index]");
But, if I use a variable that points to a map containing an Integer value
as the index, I don't get the expected results.
Iterator iter = (Iterator)context.iterate("$map/dataMap/Foo/Bar
[$map/dataMap/Foo/Count]");
It seems to return the entire contents of "$map/dataMap/Foo/Bar".
Furthermore, if I evaluate the expression "$map/dataMap/Foo/Count",
the result is 3 of type Integer, as I would expect.
Has anyone else seen any problems in this area?
The following is a simple program showing the above problems.
import java.util.*;
import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.jxpath.JXPathException;
public class TestMap3 {
public TestMap3(String args[]) {
}
private void run() {
MapHolder mh1 = new MapHolder();
JXPathContext context = JXPathContext.newContext(null, null);
context.getVariables().declareVariable("map1", mh1);
context.getVariables().declareVariable("index", new Integer(2));
// Hard-coding array index works OK
getXPathValue(context, "$map1/dataMap/Foo/Dog[2]");
// Using a simple Integer variable as the index works OK
getXPathValue(context, "$map1/dataMap/Foo/Dog[$index]");
// 1st problem: If Foo/Count is 2, this expression should return
one
// value only ("St. Bernard"), but instead returns entire list of
dogs.
// (In fact, no matter what Foo/Count is (1, 2, or 299) it always
returns
// entire list of dogs.)
getXPathValue(context, "$map1/dataMap/Foo/Count"); // verify index
value
getXPathValue(context, "$map1/dataMap/Foo/Dog
[$map1/dataMap/Foo/Count]");
// Another related problem: Use getValue(): No matter what the
value of
// Foo/Count is, it always returns 1st dog ("Shepard")
Object result = context.getValue("$map1/dataMap/Foo/Dog
[$map1/dataMap/Foo/Count]");
System.out.println("\n ****** Result using getValue():");
System.out.println(" " + result + ";\tType: " +
result.getClass().getName());
System.out.println("\n MainMap: " + mh1.getDataMap());
}
/**
* Evaluate the given expression within the JXPath context and
* display the results.
*
* Returns the result object (if more than one, returns last one)
*/
private static Object getXPathValue(JXPathContext context, String expr)
{
java.util.Iterator iter;
Object result = null;
System.out.println("\n ****** Result of \"" + expr + "\":");
iter = (java.util.Iterator)context.iterate(expr);
if (!iter.hasNext())
System.out.println(" EMPTY!!!");
else {
while (iter.hasNext()) {
result = iter.next();
System.out.println(" " + result + ";\tType: " +
result.getClass().getName());
}
}
return result;
}
/**
*
*/
public static void main(String args[]) {
TestMap3 testMap = new TestMap3(args);
testMap.run();
}
public class MapHolder {
private Map dataMap = null;
public MapHolder() {
// Populate map contents
dataMap = new HashMap();
List l0 = new ArrayList();
dataMap.put("Foo", l0);
Map m = new HashMap();
List l = new ArrayList();
m.put("Count", l);
l.add(new Integer(299));
l0.add(m);
m = new HashMap();
l = new ArrayList();
m.put("Dog", l);
l.add("Shepard");
l.add("St. Bernard");
l0.add(m);
}
public Map getDataMap() {
return dataMap;
}
}
}
Steve Pannier
Jacada, Inc.
(763) 201-0002 Ext. 219
[EMAIL PROTECTED]
http://www.jacada.com
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