* Please note that this encoder is a bit more strict than you may be used to * (the Common Query Language for example demands Equals.getExpression1() is a * PropertyName). If you used FilterFactory to produce your filter you should be * okay (as it only provides methods to make a valid Filter); if not please * expect ClassCastExceptions. *
* This visitor will return a StringBuilder; you can also provide a StringBuilder * as the data parameter in order to cut down on the number of objects * created during encoding. *
*
* FilterToCQL toCQL = new FilterToCQL();
* StringBuilder output = filter.accepts( toCQL, new StringBuilder() );
* String cql = output.toString();
*
* @author Johann Sorel
*/
class FilterToCQL implements FilterVisitor {
/** Standard java logger */
private static Logger LOGGER = org.geotools.util.logging.Logging.getLogger(FilterToCQL.class.getName());
/**
* Exclude everything; using an old SQL trick of 1=0.
*/
public Object visit(ExcludeFilter filter, Object extraData) {
return FilterToTextUtil.buildExclude(extraData);
}
/**
* Include everything; using an old SQL trick of 1=1.
*/
public Object visit(IncludeFilter filter, Object extraData) {
return FilterToTextUtil.buildInclude(extraData);
}
public Object visit(And filter, Object extraData) {
return FilterToTextUtil.buildBinaryLogicalOperator("AND", this, filter, extraData);
}
/**
* Encoding an Id filter is not supported by CQL.
* * This is because in the Catalog specification retreiving an object * by an id is a distinct operation seperate from a filter based query. */ public Object visit(Id filter, Object extraData) { throw new IllegalStateException("Cannot encode an Id as legal CQL"); } public Object visit(Not filter, Object extraData) { LOGGER.finer("exporting Not filter"); return FilterToTextUtil.buildNot(this,filter, extraData); } public Object visit(Or filter, Object extraData) { LOGGER.finer("exporting Or filter"); return FilterToTextUtil.buildBinaryLogicalOperator("OR", this, filter, extraData); } public Object visit(PropertyIsBetween filter, Object extraData) { return FilterToTextUtil.buildBetween(filter, extraData); } public Object visit(PropertyIsEqualTo filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildComparison(filter, extraData, "="); } public Object visit(PropertyIsNotEqualTo filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildComparison(filter, extraData, "!="); } public Object visit(PropertyIsGreaterThan filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildComparison(filter, extraData, ">"); } public Object visit(PropertyIsGreaterThanOrEqualTo filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildComparison(filter, extraData, ">="); } public Object visit(PropertyIsLessThan filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildComparison(filter, extraData, "<"); } public Object visit(PropertyIsLessThanOrEqualTo filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildComparison(filter, extraData, "<="); } public Object visit(PropertyIsLike filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression()); return FilterToTextUtil.buildIsLike(filter, extraData); } private void checkLeftExpressionIsProperty(Expression expr) { if(!(expr instanceof PropertyName)){ throw new RuntimeException("CQL requires a PropertyName"); } } public Object visit(PropertyIsNull filter, Object extraData) { return FilterToTextUtil.buildIsNull(filter, extraData); } public Object visit(PropertyIsNil filter, Object extraData) { throw new UnsupportedOperationException("isNil not supported"); } public Object visit(BBOX filter, Object extraData) { return FilterToTextUtil.buildBBOX(filter, extraData); } public Object visit(Beyond filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildDistanceBufferOperation("BEYOND", filter, extraData); } public Object visit(Contains filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildBinarySpatialOperator("CONTAINS", filter, extraData); } public Object visit(Crosses filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildBinarySpatialOperator("CROSSES", filter, extraData); } public Object visit(Disjoint filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildBinarySpatialOperator("DISJOINT", filter, extraData); } public Object visit(DWithin filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildDWithin(filter, extraData); } public Object visit(Equals filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildBinarySpatialOperator("EQUALS", filter, extraData); } public Object visit(Intersects filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildBinarySpatialOperator("INTERSECTS", filter, extraData); } public Object visit(Overlaps filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildBinarySpatialOperator("OVERLAP", filter, extraData); } public Object visit(Touches filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildBinarySpatialOperator("TOUCH", filter, extraData); } public Object visit(Within filter, Object extraData) { checkLeftExpressionIsProperty(filter.getExpression1()); return FilterToTextUtil.buildBinarySpatialOperator("WITHIN", filter, extraData); } /** * A filter has not been provided. *
* In general this is a bad situtation which we ask people to
* represent with Filter.INCLUDES or Filter.EXCLUDES depending
* on what behaviour they want to see happen - in this case
* literally null was provided.
*
*/ public Object visitNullFilter(Object extraData) { throw new NullPointerException("Cannot encode null as a Filter"); } public Object visit(After after, Object extraData) { return FilterToTextUtil.buildBinaryTemporalOperator("AFTER", after, extraData); } public Object visit(Before before, Object extraData) { return FilterToTextUtil.buildBinaryTemporalOperator("BEFORE", before, extraData); } public Object visit(During during, Object extraData) { return FilterToTextUtil.buildDuring(during, extraData); } public Object visit(AnyInteracts anyInteracts, Object extraData) { throw new UnsupportedOperationException("Temporal filter AnyInteracts has not a CQL expression"); } public Object visit(Begins begins, Object extraData) { throw new UnsupportedOperationException("Temporal filter Begins has not a CQL expression"); } public Object visit(BegunBy begunBy, Object extraData) { throw new UnsupportedOperationException("Temporal filter BegunBy has not a CQL expression"); } public Object visit(EndedBy endedBy, Object extraData) { throw new UnsupportedOperationException("Temporal filter EndedBy has not a CQL expression"); } public Object visit(Ends ends, Object extraData) { throw new UnsupportedOperationException("Temporal filter Ends has not a CQL expression"); } public Object visit(Meets meets, Object extraData) { throw new UnsupportedOperationException("Temporal filter Meets has not a CQL expression"); } public Object visit(MetBy metBy, Object extraData) { throw new UnsupportedOperationException("Temporal filter MetBy has not a CQL expression"); } public Object visit(OverlappedBy overlappedBy, Object extraData) { throw new UnsupportedOperationException("Temporal filter OverlappedBy not implemented"); } public Object visit(TContains contains, Object extraData) { throw new UnsupportedOperationException("Temporal filter TContains has not a CQL expression"); } public Object visit(TEquals equals, Object extraData) { throw new UnsupportedOperationException("Temporal filter TEquals has not a CQL expression"); } public Object visit(TOverlaps contains, Object extraData) { throw new UnsupportedOperationException("Temporal filter TOverlaps has not a CQL expression"); } }