/**
* Converts the String representation of a {@link Var} back into the object version.
*
* @param varString - The {@link Var} represented as a String. (not null)
* @return A {@link Var} built from the string.
*/
public static Var toVar(final String varString) {
checkNotNull(varString);
if (varString.startsWith("-const-")) {
// The variable is a constant value.
final String[] varParts = varString.split(TYPE_DELIM);
final String name = varParts[0];
final String valueString = name.substring("-const-".length());
final String dataTypeString = varParts[1];
if (dataTypeString.equals(URI_TYPE)) {
// Handle a URI object.
final Var var = new Var(name, new URIImpl(valueString));
var.setAnonymous(true);
return var;
} else {
// Literal value.
final URI dataType = new URIImpl(dataTypeString);
final Literal value = new LiteralImpl(valueString, dataType);
final Var var = new Var(name, value);
var.setAnonymous(true);
return var;
}
} else {
// The variable is a named variable.
return new Var(varString);
}
}
/**
* Create a QueryBuilder for creating a describe query
*
* @param theVars the variables to be described
* @param theValues the specific bound URI values to be described
* @return a describe query builder
*/
public static QueryBuilder<ParsedGraphQuery> describe(String[] theVars, Resource... theValues) {
QueryBuilder<ParsedGraphQuery> aBuilder =
new AbstractQueryBuilder<ParsedGraphQuery>(new ParsedGraphQuery());
aBuilder.reduced();
aBuilder.addProjectionVar("descr_subj", "descr_pred", "descr_obj");
GroupBuilder<?, ?> aGroup = aBuilder.group();
if (theVars != null) {
for (String aVar : theVars) {
Var aVarObj = new Var(aVar);
aVarObj.setAnonymous(true);
aGroup
.filter()
.or(
new SameTerm(aVarObj, new Var("descr_subj")),
new SameTerm(aVarObj, new Var("descr_obj")));
}
}
if (theValues != null) {
for (Resource aVar : theValues) {
Var aSubjVar = new Var("descr_subj");
aSubjVar.setAnonymous(true);
Var aObjVar = new Var("descr_obj");
aObjVar.setAnonymous(true);
aGroup
.filter()
.or(
new SameTerm(new ValueConstant(aVar), aSubjVar),
new SameTerm(new ValueConstant(aVar), aObjVar));
}
}
aGroup.atom("descr_subj", "descr_pred", "descr_obj");
return aBuilder;
}
