[refactor] Java21: Use SequencedCollection (readability)

Author: dizzzz

exist-core/src/main/java/org/exist/client/InteractiveClient.java

@@ -1943,7 +1943,7 @@ private boolean processCommandLineActions() throws IOException {
         } else if (options.xpath.isPresent() || !options.queryFiles.isEmpty()) {
             String xpath = null;
             if (!options.queryFiles.isEmpty()) {
-                try (final BufferedReader reader = Files.newBufferedReader(options.queryFiles.get(0))) {
+                try (final BufferedReader reader = Files.newBufferedReader(options.queryFiles.getFirst())) {
                     final StringBuilder buf = new StringBuilder();
                     String line;
                     while ((line = reader.readLine()) != null) {

exist-core/src/main/java/org/exist/collections/triggers/CSVExtractingTrigger.java

@@ -104,15 +104,15 @@ public void configure(final DBBroker broker, final Txn transaction, final Collec
         if(separators == null || separators.size() != 1) {
             throw new TriggerException("A separator parameter must be provided to the CSVExtractingTrigger configuration");
         } else {
-            this.separator = separators.get(0);
+            this.separator = separators.getFirst();
         }
 
         //get the extractions
         final List<Map<String, List>> paths = (List<Map<String, List>>)parameters.get("path");
         for(final Map<String, List> path : paths){
             final List<String> xpaths = path.get("xpath");
             if(xpaths != null && xpaths.size() == 1) {
-                String xpath = xpaths.get(0);
+                String xpath = xpaths.getFirst();
 
                 //split out the path and preficate (if present) from the xpath
                 String pathExpr;

exist-core/src/main/java/org/exist/collections/triggers/HistoryTrigger.java

@@ -81,7 +81,7 @@ public void configure(final DBBroker broker, final Txn transaction, final Collec
 
         if(parameters.containsKey(PARAM_ROOT_NAME)) {
             try {
-                rootPath = XmldbURI.xmldbUriFor(parameters.get(PARAM_ROOT_NAME).get(0).toString());
+                rootPath = XmldbURI.xmldbUriFor(parameters.get(PARAM_ROOT_NAME).getFirst().toString());
             } catch(final URISyntaxException e) {
                 throw new TriggerException(e);
             }

exist-core/src/main/java/org/exist/collections/triggers/STXTransformerTrigger.java

@@ -63,7 +63,7 @@ public class STXTransformerTrigger extends SAXTrigger implements DocumentTrigger
     @Override
     public void configure(DBBroker broker, Txn transaction, Collection parent, Map<String, List<?>> parameters) throws TriggerException {
         super.configure(broker, transaction, parent, parameters);
-        final String stylesheet = (String)parameters.get("src").get(0);
+        final String stylesheet = (String)parameters.get("src").getFirst();
         if(stylesheet == null) {
                 throw new TriggerException("STXTransformerTrigger requires an attribute 'src'");
         }

exist-core/src/main/java/org/exist/collections/triggers/XQueryTrigger.java

@@ -134,14 +134,14 @@ public void configure(final DBBroker broker, final Txn transaction, final Collec
 			}
 
  			final List<String> urlQueries = (List<String>) parameters.get("url");
-            this.urlQuery = urlQueries != null ? urlQueries.get(0) : null;
+            this.urlQuery = urlQueries != null ? urlQueries.getFirst() : null;
 
             final List<String> strQueries = (List<String>) parameters.get("query");
- 			this.strQuery = strQueries != null ? strQueries.get(0) : null;
+ 			this.strQuery = strQueries != null ? strQueries.getFirst() : null;
 
 			for (final Map.Entry<String, List<?>> entry : parameters.entrySet()) {
  				final String paramName = entry.getKey();
-				final Object paramValue = entry.getValue().get(0);
+				final Object paramValue = entry.getValue().getFirst();
 
  				//get the binding prefix (if any)
                 switch (paramName) {

exist-core/src/main/java/org/exist/config/ConfigurationImpl.java

@@ -81,7 +81,7 @@ public Configuration getConfiguration(String name) {
         if (list == null)
             {return null;}
         if (list.size() > 0)
-            {return list.get(0);}
+            {return list.getFirst();}
         return null;
     }
 

exist-core/src/main/java/org/exist/dom/persistent/Match.java

@@ -202,7 +202,7 @@ public Match continuedBy(final Match other) {
             return null;
         }
 
-        final int wildCardSize = newMatchOffsets.get(0).length - matchTerm.length() - other.matchTerm.length();
+        final int wildCardSize = newMatchOffsets.getFirst().length - matchTerm.length() - other.matchTerm.length();
         final StringBuilder matched = new StringBuilder(matchTerm);
         for (int ii = 0; ii < wildCardSize; ii++) {
             matched.append('?');
@@ -319,7 +319,7 @@ public Match filterOutOverlappingOffsets() {
             }
         });
         final List<Offset> nonOverlappingMatchOffsets = new LinkedList<>();
-        nonOverlappingMatchOffsets.add(newMatchOffsets.remove(0));
+        nonOverlappingMatchOffsets.add(newMatchOffsets.removeFirst());
         for (final Offset o : newMatchOffsets) {
             boolean overlapsExistingOffset = false;
             for (final Offset eo : nonOverlappingMatchOffsets) {

exist-core/src/main/java/org/exist/http/servlets/HttpRequestWrapper.java

@@ -494,7 +494,7 @@ public String getParameter(final String name) {
 
         // If Parameter is a List, get first entry. The data is used later on
         if (o instanceof List lst) {
-            o = lst.get(0);
+            o = lst.getFirst();
         }
 
         // If parameter is file item, convert to string

exist-core/src/main/java/org/exist/http/servlets/HttpServletRequestWrapper.java

@@ -200,7 +200,7 @@ public String getParameter(final String name) {
             final List<RequestParameter> vecParameterValues = params.get(name);
 
             //return the first value in the vector
-            return vecParameterValues.get(0).getValue();
+            return vecParameterValues.getFirst().getValue();
         } else {
             return null;
         }

exist-core/src/main/java/org/exist/http/urlrewrite/XQueryURLRewrite.java

@@ -1198,7 +1198,7 @@ public void addParameter(final String name, final String value) {
         public String getParameter(final String name) {
             final List<String> paramValues = addedParams.get(name);
             if (paramValues != null && paramValues.size() > 0) {
-                return paramValues.get(0);
+                return paramValues.getFirst();
             }
             return null;
         }