/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.data.jdbc;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Arrays;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.geotools.data.jdbc.fidmapper.FIDMapper;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.filter.FilterCapabilities;
import org.geotools.filter.FunctionImpl;
import org.geotools.filter.LikeFilterImpl;
import org.geotools.jdbc.JDBCDataStore;
import org.geotools.jdbc.PrimaryKey;
import org.geotools.util.Converters;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.feature.type.AttributeDescriptor;
import org.opengis.feature.type.GeometryDescriptor;
import org.opengis.filter.And;
import org.opengis.filter.BinaryComparisonOperator;
import org.opengis.filter.BinaryLogicOperator;
import org.opengis.filter.ExcludeFilter;
import org.opengis.filter.Filter;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.FilterVisitor;
import org.opengis.filter.Id;
import org.opengis.filter.IncludeFilter;
import org.opengis.filter.Not;
import org.opengis.filter.Or;
import org.opengis.filter.PropertyIsBetween;
import org.opengis.filter.PropertyIsEqualTo;
import org.opengis.filter.PropertyIsGreaterThan;
import org.opengis.filter.PropertyIsGreaterThanOrEqualTo;
import org.opengis.filter.PropertyIsLessThan;
import org.opengis.filter.PropertyIsLessThanOrEqualTo;
import org.opengis.filter.PropertyIsLike;
import org.opengis.filter.PropertyIsNotEqualTo;
import org.opengis.filter.PropertyIsNull;
import org.opengis.filter.expression.Add;
import org.opengis.filter.expression.BinaryExpression;
import org.opengis.filter.expression.Divide;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.ExpressionVisitor;
import org.opengis.filter.expression.Function;
import org.opengis.filter.expression.Literal;
import org.opengis.filter.expression.Multiply;
import org.opengis.filter.expression.NilExpression;
import org.opengis.filter.expression.PropertyName;
import org.opengis.filter.expression.Subtract;
import org.opengis.filter.identity.Identifier;
import org.opengis.filter.spatial.BBOX;
import org.opengis.filter.spatial.Beyond;
import org.opengis.filter.spatial.BinarySpatialOperator;
import org.opengis.filter.spatial.Contains;
import org.opengis.filter.spatial.Crosses;
import org.opengis.filter.spatial.DWithin;
import org.opengis.filter.spatial.Disjoint;
import org.opengis.filter.spatial.Equals;
import org.opengis.filter.spatial.Intersects;
import org.opengis.filter.spatial.Overlaps;
import org.opengis.filter.spatial.Touches;
import org.opengis.filter.spatial.Within;
import com.vividsolutions.jts.geom.Geometry;
/**
* Encodes a filter into a SQL WHERE statement. It should hopefully be generic
* enough that any SQL database will work with it.
* This generic SQL encoder should eventually
* be able to encode all filters except Geometry Filters.
* This is because the OGC's SFS for SQL document specifies
* two ways of doing SQL databases, one with native geometry types and one
* without. To implement an encoder for one of the two types simply subclass
* off of this encoder and put in the proper GeometryFilter visit method. Then
* add the filter types supported to the capabilities by overriding the
* {{@link #createFilterCapabilities()} method.
*
*
* This version was ported from the original to support org.opengis.filter type
* Filters.
*
* @author originally by Chris Holmes, TOPP
* @author ported by Saul Farber, MassGIS
*
* @task REVISIT: need to figure out exceptions, we're currently eating io
* errors, which is bad. Probably need a generic visitor exception.
*
*/
/*
* TODO: Use the new FilterCapabilities. This may fall out of using the new
* PrePostFilterSplitter code.
*
* TODO: Use the new Geometry classes from org.opengis. Not sure
* when this will be required, but it's on the horizon here.
*
* Non Javadoc comments:
*
* Note that the old method allowed us to write WAY fewer methods, as we didn't
* need to cover all the cases with exlpicit methods (as the new
* org.opengis.filter.FilterVisitor and ExpressionVisitor methods require
* us to do).
*
* The code is split into methods to support the FilterVisitor interface first
* then the ExpressionVisitor methods second.
*
*/
public class FilterToSQL implements FilterVisitor, ExpressionVisitor {
/** error message for exceptions */
protected static final String IO_ERROR = "io problem writing filter";
/** The filter types that this class can encode */
protected FilterCapabilities capabilities = null;
/** Standard java logger */
private static Logger LOGGER = org.geotools.util.logging.Logging.getLogger("org.geotools.filter");
/** Character used to escape database schema, table and column names */
private String sqlNameEscape = "";
/** where to write the constructed string from visiting the filters. */
protected Writer out;
/**
* the fid mapper used to encode the fid filters
* @deprecated use {@link #primaryKey}
*/
protected FIDMapper mapper;
/**
* The primary key corresponding to the table the filter is being encoded
* against.
*/
protected PrimaryKey primaryKey;
/** The schema that contains the table the filter being encoded against. */
protected String databaseSchema;
/** the schmema the encoder will be used to be encode sql for */
protected SimpleFeatureType featureType;
/** flag which indicates that the encoder is currently encoding a function */
protected boolean encodingFunction = false;
/** the geometry descriptor corresponding to the current binary spatial filter being encoded */
protected GeometryDescriptor currentGeometry;
/** the srid corresponding to the current binary spatial filter being encoded */
protected Integer currentSRID;
/**
* Default constructor
*/
public FilterToSQL() {
}
public FilterToSQL(Writer out) {
this.out = out;
}
/**
* Sets the writer the encoder will write to.
*/
public void setWriter(Writer out) {
this.out = out;
}
/**
* Performs the encoding, sends the encoded sql to the writer passed in.
*
* @param filter the Filter to be encoded.
*
* @throws OpenGISFilterToOpenGISFilterToSQLEncoderException If filter type not supported, or if there
* were io problems.
*/
public void encode(Filter filter) throws FilterToSQLException {
if (out == null) throw new FilterToSQLException("Can't encode to a null writer.");
if (getCapabilities().fullySupports(filter)) {
try {
out.write("WHERE ");
filter.accept(this, null);
//out.write(";");
} catch (java.io.IOException ioe) {
LOGGER.warning("Unable to export filter" + ioe);
throw new FilterToSQLException("Problem writing filter: ", ioe);
}
} else {
throw new FilterToSQLException("Filter type not supported");
}
}
/**
* purely a convenience method.
*
* Equivalent to:
*
* StringWriter out = new StringWriter();
* new FilterToSQL(out).encode(filter);
* out.getBuffer().toString();
*
* @param filter
* @return a string representing the filter encoded to SQL.
* @throws FilterToSQLException
*/
public String encodeToString(Filter filter) throws FilterToSQLException {
StringWriter out = new StringWriter();
this.out = out;
this.encode(filter);
return out.getBuffer().toString();
}
/**
* Performs the encoding, sends the encoded sql to the writer passed in.
*
* @param filter the Filter to be encoded.
*
* @throws OpenGISFilterToOpenGISFilterToSQLEncoderException If filter type not supported, or if there
* were io problems.
*/
public void encode(Expression expression) throws FilterToSQLException {
if (out == null) throw new FilterToSQLException("Can't encode to a null writer.");
expression.accept(this, null);
}
/**
* purely a convenience method.
*
* Equivalent to:
*
* StringWriter out = new StringWriter();
* new FilterToSQL(out).encode(filter);
* out.getBuffer().toString();
*
* @param filter
* @return a string representing the filter encoded to SQL.
* @throws FilterToSQLException
*/
public String encodeToString(Expression expression) throws FilterToSQLException {
StringWriter out = new StringWriter();
this.out = out;
this.encode(expression);
return out.getBuffer().toString();
}
/**
* Sets the featuretype the encoder is encoding sql for.
* <p>
* This is used for context for attribute expressions when encoding to sql.
* </p>
*
* @param featureType
*/
public void setFeatureType(SimpleFeatureType featureType) {
this.featureType = featureType;
}
/**
* Sets the FIDMapper that will be used in subsequente visit calls. There
* must be a FIDMapper in order to invoke the FIDFilter encoder.
*
* @param mapper
* @deprecated use {@link #setPrimaryKey(PrimaryKey)}
*/
public void setFIDMapper(FIDMapper mapper) {
this.mapper = mapper;
}
/**
* @deprecated use {@link #getPrimaryKey()}
*/
public FIDMapper getFIDMapper() {
return this.mapper;
}
public PrimaryKey getPrimaryKey() {
return primaryKey;
}
public void setPrimaryKey(PrimaryKey primaryKey) {
this.primaryKey = primaryKey;
}
public String getDatabaseSchema() {
return databaseSchema;
}
public void setDatabaseSchema(String databaseSchema) {
this.databaseSchema = databaseSchema;
}
/**
* Sets the capabilities of this filter.
*
* @return FilterCapabilities for this Filter
*/
protected FilterCapabilities createFilterCapabilities() {
FilterCapabilities capabilities = new FilterCapabilities();
capabilities.addAll(FilterCapabilities.LOGICAL_OPENGIS);
capabilities.addAll(FilterCapabilities.SIMPLE_COMPARISONS_OPENGIS);
capabilities.addType(PropertyIsNull.class);
capabilities.addType(PropertyIsBetween.class);
capabilities.addType(Id.class);
capabilities.addType(IncludeFilter.class);
capabilities.addType(ExcludeFilter.class);
return capabilities;
}
/**
* Describes the capabilities of this encoder.
*
* <p>
* Performs lazy creation of capabilities.
* </p>
*
* If you're subclassing this class, override createFilterCapabilities
* to declare which filtercapabilities you support. Don't use
* this method.
*
* @return The capabilities supported by this encoder.
*/
public synchronized final FilterCapabilities getCapabilities() {
if (capabilities == null) {
capabilities = createFilterCapabilities();
}
return capabilities; //maybe clone? Make immutable somehow
}
/**
* Sets the capabilities for the encoder.
*/
public void setCapabilities(FilterCapabilities capabilities) {
this.capabilities = capabilities;
}
// BEGIN IMPLEMENTING org.opengis.filter.FilterVisitor METHODS
/**
* @see {@link FilterVisitor#visit(ExcludeFilter, Object)}
*
* Writes the SQL for the IncludeFilter by writing "FALSE".
*
* @param the filter to be visited
*/
public Object visit(ExcludeFilter filter, Object extraData) {
try {
out.write("0 = 1");
} catch (IOException ioe) {
throw new RuntimeException(IO_ERROR, ioe);
}
return extraData;
}
/**
* @see {@link FilterVisitor#visit(IncludeFilter, Object)}
*
* Writes the SQL for the IncludeFilter by writing "TRUE".
*
* @param the filter to be visited
*
*/
public Object visit(IncludeFilter filter, Object extraData) {
try {
out.write("1 = 1");
} catch (IOException ioe) {
throw new RuntimeException(IO_ERROR, ioe);
}
return extraData;
}
/**
* Writes the SQL for the PropertyIsBetween Filter.
*
* @param filter the Filter to be visited.
*
* @throws RuntimeException for io exception with writer
*/
public Object visit(PropertyIsBetween filter, Object extraData) throws RuntimeException {
LOGGER.finer("exporting PropertyIsBetween");
Expression expr = (Expression) filter.getExpression();
Expression lowerbounds = (Expression) filter.getLowerBoundary();
Expression upperbounds = (Expression) filter.getUpperBoundary();
Class context;
AttributeDescriptor attType = (AttributeDescriptor)expr.evaluate(featureType);
if (attType != null) {
context = attType.getType().getBinding();
} else {
//assume it's a string?
context = String.class;
}
try {
expr.accept(this, extraData);
out.write(" BETWEEN ");
lowerbounds.accept(this, context);
out.write(" AND ");
upperbounds.accept(this, context);
} catch (java.io.IOException ioe) {
throw new RuntimeException(IO_ERROR, ioe);
}
return extraData;
}
/**
* Writes the SQL for the Like Filter. Assumes the current java
* implemented wildcards for the Like Filter: . for multi and .? for
* single. And replaces them with the SQL % and _, respectively.
*
* @param filter the Like Filter to be visited.
*
* @task REVISIT: Need to think through the escape char, so it works right
* when Java uses one, and escapes correctly with an '_'.
*/
public Object visit(PropertyIsLike filter, Object extraData)
{
char esc = filter.getEscape().charAt(0);
char multi = filter.getWildCard().charAt(0);
char single = filter.getSingleChar().charAt(0);
boolean matchCase = filter.isMatchingCase();
String literal = filter.getLiteral();
Expression att = filter.getExpression();
//JD: hack for date values, we append some additional padding to handle
// the matching of time/timezone/etc...
AttributeDescriptor ad = (AttributeDescriptor) att.evaluate( featureType );
if ( ad != null && Date.class.isAssignableFrom( ad.getType().getBinding() ) ) {
literal += multi;
}
String pattern = LikeFilterImpl.convertToSQL92(esc, multi, single, matchCase, literal);
try {
if (!matchCase){
out.write(" UPPER(");
}
att.accept(this, extraData);
if (!matchCase){
out.write(") LIKE '");
} else {
out.write(" LIKE '");
}
out.write(pattern);
out.write("' ");
} catch (java.io.IOException ioe) {
throw new RuntimeException(IO_ERROR, ioe);
}
return extraData;
}
/**
* Write the SQL for an And filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(And filter, Object extraData) {
return visit((BinaryLogicOperator)filter, "AND");
}
/**
* Write the SQL for a Not filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(Not filter, Object extraData) {
return visit((BinaryLogicOperator)filter, "NOT");
}
/**
* Write the SQL for an Or filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(Or filter, Object extraData) {
return visit((BinaryLogicOperator)filter, "OR");
}
/**
* Common implementation for BinaryLogicOperator filters. This way
* they're all handled centrally.
*
* @param filter the logic statement to be turned into SQL.
* @param extraData extra filter data. Not modified directly by this method.
*/
protected Object visit(BinaryLogicOperator filter, Object extraData) {
LOGGER.finer("exporting LogicFilter");
String type = (String)extraData;
try {
java.util.Iterator list = filter.getChildren().iterator();
if (filter instanceof Not) {
out.write(type + " (");
((Filter) list.next()).accept(this, extraData);
out.write(")");
} else { //AND or OR
out.write("(");
while (list.hasNext()) {
((Filter) list.next()).accept(this, extraData);
if (list.hasNext()) {
out.write(" " + type + " ");
}
}
out.write(")");
}
} catch (java.io.IOException ioe) {
throw new RuntimeException(IO_ERROR, ioe);
}
return extraData;
}
/**
* Write the SQL for this kind of filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(PropertyIsEqualTo filter, Object extraData) {
visitBinaryComparisonOperator((BinaryComparisonOperator)filter, "=");
return extraData;
}
/**
* Write the SQL for this kind of filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(PropertyIsGreaterThanOrEqualTo filter, Object extraData) {
visitBinaryComparisonOperator((BinaryComparisonOperator)filter, ">=");
return extraData;
}
/**
* Write the SQL for this kind of filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(PropertyIsGreaterThan filter, Object extraData) {
visitBinaryComparisonOperator((BinaryComparisonOperator)filter, ">");
return extraData;
}
/**
* Write the SQL for this kind of filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(PropertyIsLessThan filter, Object extraData) {
visitBinaryComparisonOperator((BinaryComparisonOperator)filter, "<");
return extraData;
}
/**
* Write the SQL for this kind of filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(PropertyIsLessThanOrEqualTo filter, Object extraData) {
visitBinaryComparisonOperator((BinaryComparisonOperator)filter, "<=");
return extraData;
}
/**
* Write the SQL for this kind of filter
*
* @param filter the filter to visit
* @param extraData extra data (unused by this method)
*
*/
public Object visit(PropertyIsNotEqualTo filter, Object extraData) {
visitBinaryComparisonOperator((BinaryComparisonOperator)filter, "!=");
return extraData;
}
/**
* Common implementation for BinaryComparisonOperator filters. This way
* they're all handled centrally.
*
* DJB: note, postgis overwrites this implementation because of the way
* null is handled. This is for <PropertyIsNull> filters and <PropertyIsEqual> filters
* are handled. They will come here with "property = null".
* NOTE:
* SELECT * FROM <table> WHERE <column> isnull; -- postgresql
* SELECT * FROM <table> WHERE isnull(<column>); -- oracle???
*
* @param filter the comparison to be turned into SQL.
*
* @throws RuntimeException for io exception with writer
*/
protected void visitBinaryComparisonOperator(BinaryComparisonOperator filter, Object extraData) throws RuntimeException {
LOGGER.finer("exporting SQL ComparisonFilter");
Expression left = filter.getExpression1();
Expression right = filter.getExpression2();
Class leftContext = null, rightContext = null;
if (left instanceof PropertyName) {
// aha! It's a propertyname, we should get the class and pass it in
// as context to the tree walker.
AttributeDescriptor attType = (AttributeDescriptor)left.evaluate(featureType);
if (attType != null) {
rightContext = attType.getType().getBinding();
}
}
if (right instanceof PropertyName) {
AttributeDescriptor attType = (AttributeDescriptor)right.evaluate(featureType);
if (attType != null) {
leftContext = attType.getType().getBinding();
}
}
//case sensitivity
boolean matchCase = true;
if ( !filter.isMatchingCase() ) {
//we only do for = and !=
if ( filter instanceof PropertyIsEqualTo ||
filter instanceof PropertyIsNotEqualTo ) {
//and only for strings
if ( String.class.equals( leftContext )
|| String.class.equals( rightContext ) ) {
matchCase = false;
}
}
}
String type = (String) extraData;
try {
if ( matchCase ) {
left.accept(this, leftContext);
out.write(" " + type + " ");
right.accept(this, rightContext);
}
else {
//wrap both sides in "lower"
FunctionImpl f = new FunctionImpl();
f.setName( "lower" );
f.setParameters(Arrays.asList(left));
f.accept(this, Arrays.asList(leftContext));
out.write(" " + type + " ");
f.setParameters(Arrays.asList(right));
f.accept(this, Arrays.asList(rightContext));
}
} catch (java.io.IOException ioe) {
throw new RuntimeException(IO_ERROR, ioe);
}
}
/**
* Writes the SQL for the Null Filter.
*
* @param filter the null filter to be written to SQL.
*
* @throws RuntimeException for io exception with writer
*/
public Object visit(PropertyIsNull filter, Object extraData) throws RuntimeException {
LOGGER.finer("exporting NullFilter");
Expression expr = filter.getExpression();
try {
expr.accept(this, extraData);
out.write(" IS NULL ");
} catch (java.io.IOException ioe) {
throw new RuntimeException(IO_ERROR, ioe);
}
return extraData;
}
/**
* Encodes an Id filter
*
* @param filter the
*
* @throws RuntimeException If there's a problem writing output
*
*/
public Object visit(Id filter, Object extraData) {
if (mapper == null) {
throw new RuntimeException(
"Must set a fid mapper before trying to encode FIDFilters");
}
Set ids = filter.getIdentifiers();
LOGGER.finer("Exporting FID=" + ids);
// prepare column name array
String[] colNames = new String[mapper.getColumnCount()];
for (int i = 0; i < colNames.length; i++) {
colNames[i] = mapper.getColumnName(i);
}
for (Iterator i = ids.iterator(); i.hasNext(); ) {
try {
Identifier id = (Identifier) i.next();
Object[] attValues = mapper.getPKAttributes(id.toString());
out.write("(");
for (int j = 0; j < attValues.length; j++) {
out.write( escapeName(colNames[j]) );
out.write(" = '");
out.write(attValues[j].toString()); //DJB: changed this to attValues[j] from attValues[i].
out.write("'");
if (j < (attValues.length - 1)) {
out.write(" AND ");
}
}
out.write(")");
if (i.hasNext()) {
out.write(" OR ");
}
} catch (java.io.IOException e) {
throw new RuntimeException(IO_ERROR, e);
}
}
return extraData;
}
public Object visit(BBOX filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Beyond filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Contains filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Crosses filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Disjoint filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(DWithin filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Equals filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Intersects filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Overlaps filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Touches filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
public Object visit(Within filter, Object extraData) {
return visitBinarySpatialOperator((BinarySpatialOperator)filter, extraData);
}
protected Object visitBinarySpatialOperator(BinarySpatialOperator filter,
Object extraData) {
// basic checks
if (filter == null)
throw new NullPointerException(
"Filter to be encoded cannot be null");
if (!(filter instanceof BinaryComparisonOperator))
throw new IllegalArgumentException(
"This filter is not a binary comparison, "
+ "can't do SDO relate against it: "
+ filter.getClass());
// extract the property name and the geometry literal
PropertyName property;
Literal geometry;
BinaryComparisonOperator op = (BinaryComparisonOperator) filter;
if (op.getExpression1() instanceof PropertyName
&& op.getExpression2() instanceof Literal) {
property = (PropertyName) op.getExpression1();
geometry = (Literal) op.getExpression2();
} else if (op.getExpression2() instanceof PropertyName
&& op.getExpression1() instanceof Literal) {
property = (PropertyName) op.getExpression2();
geometry = (Literal) op.getExpression1();
} else {
throw new IllegalArgumentException(
"Can only encode spatial filters that do "
+ "compare a property name and a geometry");
}
// handle native srid
currentGeometry = null;
currentSRID = null;
if (featureType != null) {
// going thru evaluate ensures we get the proper result even if the
// name has
// not been specified (convention -> the default geometry)
AttributeDescriptor descriptor = (AttributeDescriptor) property
.evaluate(featureType);
if (descriptor instanceof GeometryDescriptor) {
currentGeometry = (GeometryDescriptor) descriptor;
currentSRID = (Integer) descriptor.getUserData().get(
JDBCDataStore.JDBC_NATIVE_SRID);
}
}
return visitBinarySpatialOperator(filter, property, geometry, filter
.getExpression1() instanceof Literal, extraData);
}
protected Object visitBinarySpatialOperator(BinarySpatialOperator filter,
PropertyName property, Literal geometry, boolean swapped,
Object extraData) {
throw new RuntimeException(
"Subclasses must implement this method in order to handle geometries");
}
/**
* Encodes a null filter value. The current implementation
* does exactly nothing.
* @param extraData extra data to be used to evaluate the filter
* @return the untouched extraData parameter
*/
public Object visitNullFilter(Object extraData) {
return extraData;
}
// END IMPLEMENTING org.opengis.filter.FilterVisitor METHODS
// START IMPLEMENTING org.opengis.filter.ExpressionVisitor METHODS
/**
* Writes the SQL for the attribute Expression.
*
* @param expression the attribute to turn to SQL.
*
* @throws RuntimeException for io exception with writer
*/
public Object visit(PropertyName expression, Object extraData) throws RuntimeException {
LOGGER.finer("exporting PropertyName");
try {
//first evaluate expression against feautre type get the attribute,
// this handles xpath
AttributeDescriptor attribute = null;
try {
attribute = (AttributeDescriptor) expression.evaluate(featureType);
}
catch( Exception e ) {
//just log and fall back on just encoding propertyName straight up
String msg = "Error occured mapping " + expression + " to feature type";
LOGGER.log( Level.WARNING, msg, e );
}
if ( attribute != null ) {
//use the name of the attribute
out.write(escapeName(attribute.getLocalName()));
}
else {
//fall back to just encoding the properyt name
out.write(escapeName(expression.getPropertyName()));
}
} catch (java.io.IOException ioe) {
throw new RuntimeException("IO problems writing attribute exp", ioe);
}
return extraData;
}
/**
* Export the contents of a Literal Expresion
*
* @param expression
* the Literal to export
*
* @throws RuntimeException
* for io exception with writer
*/
public Object visit(Literal expression, Object context)
throws RuntimeException {
LOGGER.finer("exporting LiteralExpression");
// type to convert the literal to
Class target = null;
if ( context instanceof Class ) {
target = (Class) context;
}
try {
//evaluate the expression
Object literal = evaluateLiteral( expression, target );
// handle geometry case
if (literal instanceof Geometry) {
// call this method for backwards compatibility with subclasses
visitLiteralGeometry(CommonFactoryFinder.getFilterFactory(null).literal(literal));
} else {
// write out the literal allowing subclasses to override this
// behaviour (for writing out dates and the like using the BDMS custom functions)
writeLiteral(literal);
}
} catch (IOException e) {
throw new RuntimeException("IO problems writing literal", e);
}
return context;
}
protected Object evaluateLiteral(Literal expression, Class target ) {
Object literal = null;
// HACK: let expression figure out the right value for numbers,
// since the context is almost always improperly set and the
// numeric converters try to force floating points to integrals
if(target != null && !(Number.class.isAssignableFrom(target)))
// use the target type
literal = expression.evaluate(null, target);
// if the target was not known, of the conversion failed, try the
// type guessing dance literal expression does only for the following
// method call
if(literal == null)
literal = expression.evaluate(null);
// if that failed as well, grab the value as is
if(literal == null)
literal = expression.getValue();
return literal;
}
/**
* Writes out a non null, non geometry literal. The base class properly handles
* null, numeric and booleans (true|false), and turns everything else into a string.
* Subclasses are expected to override this shall they need a different treatment
* (e.g. for dates)
* @param literal
* @throws IOException
*/
protected void writeLiteral(Object literal) throws IOException {
if(literal == null) {
out.write("NULL");
} else if(literal instanceof Number || literal instanceof Boolean) {
out.write(String.valueOf(literal));
} else {
// we don't know what this is, let's convert back to a string
String encoding = (String) Converters.convert(literal,
String.class, null);
if (encoding == null) {
// could not convert back to string, use original l value
encoding = literal.toString();
}
// sigle quotes must be escaped to have a valid sql string
String escaped = encoding.replaceAll("'", "''");
out.write("'" + escaped + "'");
}
}
/**
* Subclasses must implement this method in order to encode geometry
* filters according to the specific database implementation
*
* @param expression
*
* @throws IOException DOCUMENT ME!
* @throws RuntimeException DOCUMENT ME!
*/
protected void visitLiteralGeometry(Literal expression)
throws IOException {
throw new RuntimeException(
"Subclasses must implement this method in order to handle geometries");
}
public Object visit(Add expression, Object extraData) {
return visit((BinaryExpression)expression, "+", extraData);
}
public Object visit(Divide expression, Object extraData) {
return visit((BinaryExpression)expression, "/", extraData);
}
public Object visit(Multiply expression, Object extraData) {
return visit((BinaryExpression)expression, "*", extraData);
}
public Object visit(Subtract expression, Object extraData) {
return visit((BinaryExpression)expression, "-", extraData);
}
/**
* Writes the SQL for the Math Expression.
*
* @param expression the Math phrase to be written.
* @param operator The operator of the expression.
*
* @throws RuntimeException for io problems
*/
protected Object visit(BinaryExpression expression, String operator, Object extraData) throws RuntimeException {
LOGGER.finer("exporting Expression Math");
try {
expression.getExpression1().accept(this, extraData);
out.write(" " + operator + " ");
expression.getExpression2().accept(this, extraData);
} catch (java.io.IOException ioe) {
throw new RuntimeException("IO problems writing expression", ioe);
}
return extraData;
}
/**
* Writes sql for a function expression.
*
* @param expression a function expression
*
* @throws RuntimeException If an IO error occurs.
*/
public Object visit(Function function, Object extraData) throws RuntimeException {
try {
List<Expression> parameters = function.getParameters();
List contexts = null;
//check context, if a list which patches parameter size list assume its context
// to pass along to each Expression for encoding
if( extraData instanceof List && ((List)extraData).size() == parameters.size() ) {
contexts = (List) extraData;
}
//set the encoding function flag to signal we are inside a function
encodingFunction = true;
//write the name
out.write( function.getName() );
//write the arguments
out.write( "(");
for ( int i = 0; i < parameters.size(); i++ ) {
Expression e = parameters.get( i );
Object context = contexts != null ? contexts.get( i ) : extraData;
e.accept(this, context);
if ( i < parameters.size()-1 ) {
out.write( ",");
}
}
out.write( ")");
//reset the encoding function flag
encodingFunction = false;
}
catch (IOException e) {
throw new RuntimeException( e );
}
return extraData;
}
public Object visit(NilExpression expression, Object extraData) {
try {
out.write(" ");
} catch (java.io.IOException ioe) {
throw new RuntimeException("IO problems writing expression", ioe);
}
return extraData;
}
/**
* Sets the SQL name escape string.
*
* <p>
* The value of this string is prefixed and appended to table schema names,
* table names and column names in an SQL statement to support mixed-case
* and non-English names. Without this, the DBMS may assume a mixed-case
* name in the query should be treated as upper-case and an SQLCODE of
* -204 or 206 may result if the name is not found.
* </p>
*
* <p>
* Typically this is the double-quote character, ", but may not be for all
* databases.
* </p>
*
* <p>
* For example, consider the following query:
* </p>
*
* <p>
* SELECT Geom FROM Spear.ArchSites May be interpreted by the database as:
* SELECT GEOM FROM SPEAR.ARCHSITES If the column and table names were
* actually created using mixed-case, the query needs to be specified as:
* SELECT "Geom" from "Spear"."ArchSites"
* </p>
*
* @param escape the character to be used to escape database names
*/
public void setSqlNameEscape(String escape) {
sqlNameEscape = escape;
}
/**
* Surrounds a name with the SQL escape character.
*
* @param name
*
* @return DOCUMENT ME!
*/
public String escapeName(String name) {
return sqlNameEscape + name + sqlNameEscape;
}
}