Changed hashmap to Treemap per code rabbits suggestion

Author: gitnes94

src/main/java/org/example/http/HttpResponseBuilder.java

@@ -3,13 +3,14 @@
 import java.nio.charset.StandardCharsets;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.TreeMap;
 
 public class HttpResponseBuilder {
 
     private static final String PROTOCOL = "HTTP/1.1";
     private int statusCode = 200;
     private String body = "";
-    private Map<String, String> headers = new LinkedHashMap<>();
+    private Map<String, String> headers = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
 
     private static final String CRLF = "\r\n";
 
@@ -41,34 +42,17 @@ public void setContentTypeFromFilename(String filename) {
             404, "Not Found",
             500, "Internal Server Error");
 
-    public String build() {
+    public String build(){
         StringBuilder sb = new StringBuilder();
         String reason = REASON_PHRASES.getOrDefault(statusCode, "OK");
-
-        // Status line
         sb.append(PROTOCOL).append(" ").append(statusCode).append(" ").append(reason).append(CRLF);
-
-        // User-defined headers
-        headers.forEach((k, v) -> sb.append(k).append(": ").append(v).append(CRLF));
-
-        // Only append Content-Length if not already set
-        if (!headers.containsKey("Content-Length")) {
-            sb.append("Content-Length: ")
-                    .append(body.getBytes(StandardCharsets.UTF_8).length)
-                    .append(CRLF);
-        }
-
-        // Only append Connection if not already set
-        if (!headers.containsKey("Connection")) {
-            sb.append("Connection: close").append(CRLF);
-        }
-
-        // Blank line before body
+        headers.forEach((k,v) -> sb.append(k).append(": ").append(v).append(CRLF));
+        sb.append("Content-Length: ")
+                .append(body.getBytes(StandardCharsets.UTF_8).length);
+        sb.append(CRLF);
+        sb.append("Connection: close").append(CRLF);
         sb.append(CRLF);
-
-        // Body
         sb.append(body);
-
         return sb.toString();
     }
 }