prevent empty argument errors (#655)

Some xsl crosswalks call functions that expect parameters, but for various reasons, parameters are empty. That is now checked and logged.

Author: MajoBerger

dspace-oai/src/main/java/org/dspace/xoai/services/impl/resources/functions/LogMissingFn.java

@@ -20,6 +20,7 @@
 import net.sf.saxon.s9api.SequenceType;
 import net.sf.saxon.s9api.XdmAtomicValue;
 import net.sf.saxon.s9api.XdmValue;
+import org.apache.logging.log4j.Logger;
 import org.bouncycastle.util.Arrays;
 import org.dspace.utils.XslLogUtil;
 
@@ -30,6 +31,7 @@
  */
 public class LogMissingFn implements ExtensionFunction {
 
+    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(LogMissingFn.class);
     @Override
     public QName getName() {
         return new QName(BASE, "logMissing");
@@ -53,8 +55,27 @@ public XdmValue call(XdmValue[] xdmValues) throws SaxonApiException {
         if (Objects.isNull(xdmValues) || Arrays.isNullOrContainsNull(xdmValues)) {
             return new XdmAtomicValue("");
         }
-        return new XdmAtomicValue(checks(XslLogUtil.logMissing(xdmValues[0].itemAt(0).getStringValue(),
-                xdmValues[1].itemAt(0).getStringValue())));
+
+        String val0;
+        try {
+            val0 = xdmValues[0].itemAt(0).getStringValue();
+        } catch (Exception e) {
+            // e.g. when no parameter is passed and xdmValues[0] ends with index error
+            log.warn("Empty value to call of function LogMissingFn in the first argument");
+            val0 = "";
+        }
+
+        String val1;
+        try {
+            val1 = xdmValues[1].itemAt(0).getStringValue();
+        } catch (Exception e) {
+            // e.g. when no parameter is passed and xdmValues[0] ends with index error
+            log.warn("Empty value to call of function LogMissingFn in the second argument");
+            val1 = "";
+        }
+
+
+        return new XdmAtomicValue(checks(XslLogUtil.logMissing(val0,val1)));
     }
 
     private String checks(String got) {

dspace-oai/src/main/java/org/dspace/xoai/services/impl/resources/functions/NodeListXslFunction.java

@@ -8,7 +8,6 @@
 
 package org.dspace.xoai.services.impl.resources.functions;
 
-import static org.apache.logging.log4j.LogManager.getLogger;
 import static org.dspace.xoai.services.impl.resources.functions.StringXSLFunction.BASE;
 
 import java.util.Objects;
@@ -38,12 +37,10 @@
  */
 public abstract class NodeListXslFunction implements ExtensionFunction {
 
+    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(NodeListXslFunction.class);
     protected abstract String getFnName();
 
     protected abstract NodeList getNodeList(String param);
-
-    private static final Logger log = getLogger(NodeListXslFunction.class);
-
     @Override
     final public QName getName() {
         return new QName(BASE, getFnName());
@@ -58,7 +55,7 @@ final public SequenceType getResultType() {
     final public SequenceType[] getArgumentTypes() {
         return new SequenceType[]{
                 SequenceType.makeSequenceType(
-                        ItemType.STRING, OccurrenceIndicator.ONE)};
+                        ItemType.STRING, OccurrenceIndicator.ZERO_OR_MORE)};
     }
 
     @Override
@@ -67,7 +64,17 @@ final public XdmValue call(XdmValue[] xdmValues) throws SaxonApiException {
             return new XdmAtomicValue("");
         }
 
-        NodeList nodeList = getNodeList(xdmValues[0].itemAt(0).getStringValue());
+        String val;
+        try {
+            val = xdmValues[0].itemAt(0).getStringValue();
+        } catch (Exception e) {
+            // e.g. when no parameter is passed and xdmValues[0] ends with index error
+            log.warn("Empty value in call of function of NodeListXslFunction type");
+            val = "";
+        }
+
+
+        NodeList nodeList = getNodeList(val);
         Node oneNode = nodeList.item(0);
 
         DocumentBuilder db = new Processor(false).newDocumentBuilder();

dspace-oai/src/main/java/org/dspace/xoai/services/impl/resources/functions/NodeXslFunction.java

@@ -25,6 +25,7 @@
 import net.sf.saxon.s9api.SequenceType;
 import net.sf.saxon.s9api.XdmAtomicValue;
 import net.sf.saxon.s9api.XdmValue;
+import org.apache.logging.log4j.Logger;
 import org.bouncycastle.util.Arrays;
 import org.w3c.dom.Node;
 
@@ -35,6 +36,7 @@
  */
 public abstract class NodeXslFunction implements ExtensionFunction {
 
+    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(NodeXslFunction.class);
     protected abstract String getFnName();
 
     protected abstract Node getNode(String param);
@@ -61,7 +63,16 @@ final public XdmValue call(XdmValue[] xdmValues) throws SaxonApiException {
         if (Objects.isNull(xdmValues) || Arrays.isNullOrContainsNull(xdmValues)) {
             return new XdmAtomicValue("");
         }
-        Node node = getNode(xdmValues[0].itemAt(0).getStringValue());
+        String val;
+        try {
+            val = xdmValues[0].itemAt(0).getStringValue();
+        } catch (Exception e) {
+            // e.g. when no parameter is passed and xdmValues[0] ends with index error
+            log.warn("Empty value in call of function of NodeXslFunction type");
+            val = "";
+        }
+
+        Node node = getNode(val);
         if (Objects.isNull(node)) {
             try {
                 node = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();

dspace-oai/src/main/java/org/dspace/xoai/services/impl/resources/functions/StringXSLFunction.java

@@ -18,6 +18,7 @@
 import net.sf.saxon.s9api.SequenceType;
 import net.sf.saxon.s9api.XdmAtomicValue;
 import net.sf.saxon.s9api.XdmValue;
+import org.apache.logging.log4j.Logger;
 import org.bouncycastle.util.Arrays;
 
 
@@ -28,6 +29,7 @@
  */
 public abstract class StringXSLFunction implements ExtensionFunction {
 
+    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(StringXSLFunction.class);
     public static final String BASE = "http://custom.crosswalk.functions";
 
     protected String uncertainString(Object val) {
@@ -63,7 +65,17 @@ final public XdmValue call(XdmValue[] xdmValues) throws SaxonApiException {
         if (Objects.isNull(xdmValues) || Arrays.isNullOrContainsNull(xdmValues)) {
             return new XdmAtomicValue("");
         }
-        return new XdmAtomicValue(checks(getStringResult(xdmValues[0].itemAt(0).getStringValue())));
+
+        String val;
+        try {
+            val = xdmValues[0].itemAt(0).getStringValue();
+        } catch (Exception e) {
+            // e.g. when no parameter is passed and xdmValues[0] ends with index error
+            log.warn("Empty value in call of function of StringXslFunction type");
+            val = "";
+        }
+
+        return new XdmAtomicValue(checks(getStringResult(val)));
     }
 
     private String checks(String got) {