Optimise performance by instantiating context only once

Author: leonardehrenfried

application/src/ext/java/org/opentripplanner/ext/ojp/trias/OjpToTriasTransformer.java

@@ -29,6 +29,8 @@ class OjpToTriasTransformer {
     "trias_to_ojp2.0_request.xslt"
   );
 
+  private static final JAXBContext CONTEXT = jaxbContext();
+
   static String transform(OJP ojp) {
     var writer = new StringWriter();
     transform(ojp, writer);
@@ -37,8 +39,7 @@ static String transform(OJP ojp) {
 
   static void transform(OJP ojp, Writer writer) {
     try {
-      var context = JAXBContext.newInstance(OJP.class);
-      var marshaller = context.createMarshaller();
+      var marshaller = CONTEXT.createMarshaller();
 
       // Convert Java object to XML string
       var outputStream = new ByteArrayOutputStream();
@@ -53,8 +54,6 @@ static void transform(OJP ojp, Writer writer) {
   }
 
   static OJP triasToOjp(String trias) throws JAXBException, TransformerException {
-    var context = JAXBContext.newInstance(OJP.class);
-
     var xmlSource = new StreamSource(
       new ByteArrayInputStream(trias.getBytes(StandardCharsets.UTF_8))
     );
@@ -64,7 +63,7 @@ static OJP triasToOjp(String trias) throws JAXBException, TransformerException {
     transformer.transform(xmlSource, new StreamResult(writer));
     var transformedXml = writer.toString(StandardCharsets.UTF_8);
 
-    var unmarshaller = context.createUnmarshaller();
+    var unmarshaller = CONTEXT.createUnmarshaller();
     return (OJP) unmarshaller.unmarshal(
       new ByteArrayInputStream(transformedXml.getBytes(StandardCharsets.UTF_8))
     );
@@ -87,4 +86,12 @@ static Templates loadTemplate(String name) {
       throw new RuntimeException(e);
     }
   }
+
+  private static JAXBContext jaxbContext() {
+    try {
+      return JAXBContext.newInstance(OJP.class);
+    } catch (JAXBException e) {
+      throw new RuntimeException(e);
+    }
+  }
 }