refactor: Trim the last of the gzip code

Collapses the byte-body content-type resolution into two expressions and
inlines the remaining single-use string constants.

Author: thced

src/main/java/com/retailsvc/http/internal/ResponseCompression.java

@@ -8,9 +8,6 @@
 /** Response content-coding policy, and the gzip primitives the renderer writes through. */
 public final class ResponseCompression {
 
-  private static final String TEXT_PREFIX = "text/";
-  private static final String EVENT_STREAM = "text/event-stream";
-
   private static final Set<String> COMPRESSIBLE_TYPES =
       Set.of(
           "application/json",
@@ -35,8 +32,8 @@ public static boolean isCompressible(String contentType) {
       return false;
     }
     String mediaType = ContentTypeHeader.mediaType(contentType);
-    if (mediaType.startsWith(TEXT_PREFIX)) {
-      return !EVENT_STREAM.equals(mediaType);
+    if (mediaType.startsWith("text/")) {
+      return !"text/event-stream".equals(mediaType);
     }
     if (mediaType.endsWith("+json") || mediaType.endsWith("+xml") || mediaType.endsWith("+yaml")) {
       return true;

src/main/java/com/retailsvc/http/internal/ResponseRenderer.java

@@ -129,15 +129,9 @@ private static long declaredLength(Headers headers) {
   private void renderBytes(
       HttpExchange exchange, Headers headers, int status, String contentType, Object body)
       throws IOException {
-    byte[] bytes;
-    String effectiveContentType;
-    if (body instanceof byte[] raw) {
-      bytes = raw;
-      effectiveContentType = contentType != null ? contentType : OCTET_STREAM;
-    } else {
-      effectiveContentType = contentType != null ? contentType : DEFAULT_JSON;
-      bytes = serialize(body, effectiveContentType);
-    }
+    String effectiveContentType =
+        contentType != null ? contentType : (body instanceof byte[] ? OCTET_STREAM : DEFAULT_JSON);
+    byte[] bytes = body instanceof byte[] raw ? raw : serialize(body, effectiveContentType);
     defaultContentType(headers, effectiveContentType);
     byte[] payload = maybeCompress(exchange, headers, status, effectiveContentType, bytes);
     exchange.sendResponseHeaders(status, payload.length == 0 ? -1 : payload.length);