be.ugent.rml.functions.FunctionUtils Maven / Gradle / Ivy
package be.ugent.rml.functions;
import be.ugent.rml.NAMESPACES;
import be.ugent.rml.Utils;
import be.ugent.rml.store.Quad;
import be.ugent.rml.store.QuadStore;
import be.ugent.rml.term.NamedNode;
import be.ugent.rml.term.Term;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.time.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class FunctionUtils {
private static final Logger logger = LoggerFactory.getLogger(FunctionUtils.class);
public static Class functionRequire(File file, String className) throws IOException {
String path = file.getPath();
if (path.endsWith(".jar")) {
return FunctionUtils.getClass(file, className, "application/java-archive");
} else if (path.endsWith(".java")) {
return FunctionUtils.getClass(file, className, "text/x-java-source");
}
throw new IOException("Not a valid path for a JAVA implementation: " + path);
}
public static List getFunctionParameterUris(QuadStore store, List parameterResources) {
List parameterPredicates = new ArrayList<>();
for (Term subject : parameterResources) {
parameterPredicates.add(Utils.getObjectsFromQuads(getQuadsByFunctionPrefix(store, subject, "predicate", null)).get(0));
}
return parameterPredicates;
}
public static Class[] parseFunctionParameters(QuadStore store, List parameterResources) {
Class[] args = new Class[parameterResources.size()];
for (int i = 0; i < parameterResources.size(); i++) {
Term subject = parameterResources.get(i);
Term type = Utils.getObjectsFromQuads(getQuadsByFunctionPrefix(store, subject, "type", null)).get(0);
try {
args[i] = FunctionUtils.getParamType(type);
} catch (Exception e) {
args[i] = String.class;
}
}
return args;
}
/**
* Generates strings from a function object. Possible lists/sets/bags/... in the object are unrolled recursively
* and a string value is generated from each "simple" (i.e., not a list/set/bag/...) child object.
*
* @param o Function object, can be iterable.
* @param result A string list to which string values of objects are added
*/
public static void functionObjectToList(Object o, List result) {
if (o != null) {
// if o has child objects, recursively call this function on each child
if (o instanceof Iterable) {
((Iterable) o).forEach(item -> {
functionObjectToList(item, result);
});
}
// if o has no children, call toString() to serialize it into a string
else {
// numeric and boolean types are trivially serialized correctly
// times/dates objects in the java.time package use the relevant ISO-8601 standard,
// which is also used by xsd types and thus RDF types
result.add(o.toString());
}
}
}
private static Class getParamType(Term type) {
String typeStr = type.getValue();
switch (typeStr) {
// This is quite crude, based on https://www.w3.org/TR/xmlschema11-2/#built-in-datatypes
case "http://www.w3.org/2001/XMLSchema#any":
return Object.class;
case "http://www.w3.org/2001/XMLSchema#string":
return String.class;
case "http://www.w3.org/2001/XMLSchema#unsignedLong":
case "http://www.w3.org/2001/XMLSchema#long":
return Long.class;
case "http://www.w3.org/2001/XMLSchema#integer":
case "http://www.w3.org/2001/XMLSchema#int":
case "http://www.w3.org/2001/XMLSchema#short":
case "http://www.w3.org/2001/XMLSchema#byte":
case "http://www.w3.org/2001/XMLSchema#nonNegativeInteger":
case "http://www.w3.org/2001/XMLSchema#positiveInteger":
case "http://www.w3.org/2001/XMLSchema#unsignedInt":
case "http://www.w3.org/2001/XMLSchema#unsignedShort":
case "http://www.w3.org/2001/XMLSchema#unsignedByte":
case "http://www.w3.org/2001/XMLSchema#nonPositiveInteger":
case "http://www.w3.org/2001/XMLSchema#negativeInteger":
return Integer.class;
case "http://www.w3.org/2001/XMLSchema#boolean":
return Boolean.class;
case "http://www.w3.org/2001/XMLSchema#date":
// "Local" just means "without a time zone"
return LocalDate.class;
case "http://www.w3.org/2001/XMLSchema#dateTime":
// again "Local" means "without a time zone"
// (An xsd:dateTime actually has an OPTIONAL time zone, so there is a small semantic difference
// with java.time.LocalDateTime, this is a best effort.)
return LocalDateTime.class;
case "http://www.w3.org/2001/XMLSchema#dateTimeStamp":
return ZonedDateTime.class;
case "http://www.w3.org/2001/XMLSchema#dayTimeDuration":
case "http://www.w3.org/2001/XMLSchema#yearMonthDuration":
return Duration.class;
case "http://www.w3.org/2001/XMLSchema#gDay":
// TODO there is no java.time equivalent of xsd:day
// (There is java.time.DayOfWeek, but xsd:day would corresponds to java.time.DayOfMonth .)
throw new DateTimeException("There is no java.time equivalent of xsd:day. Crashing.");
case "http://www.w3.org/2001/XMLSchema#gMonth":
return Month.class;
case "http://www.w3.org/2001/XMLSchema#gMonthDay":
return MonthDay.class;
case "http://www.w3.org/2001/XMLSchema#gYear":
return Year.class;
case "http://www.w3.org/2001/XMLSchema#gYearMonth":
return YearMonth.class;
case "http://www.w3.org/2001/XMLSchema#decimal":
case "http://www.w3.org/2001/XMLSchema#double":
case "http://www.w3.org/2001/XMLSchema#float":
return Double.class;
case "http://www.w3.org/1999/02/22-rdf-syntax-ns#List":
return List.class;
default:
throw new Error("Couldn't derive type from " + type);
}
}
private static Class getClass(File sourceFile, String className, String mime) throws IOException {
logger.info("Found class on path " + sourceFile.getCanonicalPath());
switch (mime) {
case "text/x-java-source":
return FunctionUtils.getClassFromJAVA(sourceFile, className);
case "application/java-archive":
return FunctionUtils.getClassFromJAR(sourceFile, className);
}
return null;
}
private static Class getClassFromJAVA(File sourceFile, String className) {
Class cls = null;
// TODO let's not recompile every time
// Compile source file.
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
int res = compiler.run(null, null, null, sourceFile.getPath());
if (res != 0) {
return null;
}
// Load and instantiate compiled class.
URLClassLoader classLoader = null;
try {
classLoader = URLClassLoader.newInstance(new URL[]{(new File(sourceFile.getParent())).toURI().toURL()});
cls = Class.forName(className, true, classLoader);
} catch (MalformedURLException | ClassNotFoundException e) {
e.printStackTrace();
}
return cls;
}
private static Class getClassFromJAR(File sourceFile, String className) {
Class cls = null;
URLClassLoader child = null;
try {
child = URLClassLoader.newInstance(new URL[]{sourceFile.toURI().toURL()});
cls = Class.forName(className, true, child);
} catch (MalformedURLException | ClassNotFoundException e) {
e.printStackTrace();
}
return cls;
}
/**
* Retrieve triples of a store based on a predicate, taking into account deprecated FnO prefixed predicates
* @param store The triple store to retrieve the triples from
* @param s the subject
* @param functionTerm the unprefixed function term
* @param o the object
* @return the quads that are conform to the triple pattern fragment
*/
static List getQuadsByFunctionPrefix(QuadStore store, Term s, String functionTerm, Term o) {
List prefices = Arrays.asList(NAMESPACES.FNO_S, NAMESPACES.FNO, NAMESPACES.FNO_OLD);
return getQuadsByPrefix(store, s, functionTerm, o, prefices);
}
/**
* Retrieve triples of a store based on a predicate, taking into account multiple prefixes
* @param store The triple store to retrieve the triples from
* @param s the subject
* @param pString the unprefixed predicate term
* @param o the object
* @param prefices the list of prefices on which to look for, in order of 'correctness' (all prefixes except for the first one are assumed deprecated)
* @return the quads that are conform to the triple pattern fragment
*/
private static List getQuadsByPrefix(QuadStore store, Term s, String pString, Term o, List prefices) {
String preferredPrefix = prefices.get(0);
Term realTerm;
List quads = new ArrayList<>();
for (int i = 0; i < prefices.size(); i++) {
realTerm = new NamedNode(prefices.get(i) + pString);
quads = store.getQuads(s, realTerm, o);
if (quads.size() > 0) {
if (i != 0) {
logger.warn(prefices.get(i) + "is a deprecated prefix, please use " + preferredPrefix);
}
return quads;
}
}
return quads;
}
}
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