Fix gzip support for Jetty

Plan/api/src/main/java/com/djrapitops/plan/delivery/web/resolver/ResponseBuilder.java

@@ -66,6 +66,11 @@ public class ResponseBuilder {
         return this;
     }
 
+    protected ResponseBuilder removeHeader(String header) {
+        response.headers.remove(header);
+        return this;
+    }
+
     /**
      * Utility method for building redirects.
      *
@@ -103,7 +108,8 @@ public class ResponseBuilder {
             }
         }
 
-        return setContent(content.getBytes(charset));
+        return setContent(content.getBytes(charset))
+                .removeHeader("Accept-Ranges"); // Can compress
     }
 
     /**

Plan/common/src/main/java/com/djrapitops/plan/delivery/webserver/http/JettyResponseSender.java

@@ -16,13 +16,16 @@
  */
 package com.djrapitops.plan.delivery.webserver.http;
 
+import com.djrapitops.plan.delivery.web.resolver.MimeType;
 import com.djrapitops.plan.delivery.web.resolver.Response;
 import com.djrapitops.plan.delivery.webserver.Addresses;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import org.apache.commons.lang3.StringUtils;
 import org.eclipse.jetty.http.HttpHeader;
 
 import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Map;
@@ -43,16 +46,23 @@ public class JettyResponseSender {
     }
 
     public void send() throws IOException {
-        setResponseHeaders();
         if ("HEAD".equals(servletRequest.getMethod()) || response.getCode() == 204) {
+            setResponseHeaders();
             sendHeadResponse();
-        } else if ("bytes".equalsIgnoreCase(response.getHeaders().get(HttpHeader.ACCEPT_RANGES.asString()))) {
+        } else if (canGzip()) {
-            sendRawBytes();
-        } else {
             sendCompressed();
+        } else {
+            setResponseHeaders();
+            sendRawBytes();
         }
     }
 
+    private boolean canGzip() {
+        String method = servletRequest.getMethod();
+        String mimeType = response.getHeaders().get(HttpHeader.CONTENT_TYPE.asString());
+        return "GET".equals(method) && StringUtils.containsAny(mimeType, MimeType.HTML, MimeType.CSS, MimeType.JS, MimeType.JSON, "text/plain");
+    }
+
     public void sendHeadResponse() throws IOException {
         try {
             response.getHeaders().remove(HttpHeader.CONTENT_LENGTH.asString());
@@ -72,22 +82,40 @@ public class JettyResponseSender {
     }
 
     private void correctRedirect(Map<String, String> responseHeaders) {
-        String redirect = responseHeaders.get("Location");
+        String redirect = responseHeaders.get(HttpHeader.LOCATION.asString());
         if (redirect != null) {
             if (redirect.startsWith("http") || !redirect.startsWith("/")) return;
-            addresses.getAccessAddress().ifPresent(address -> responseHeaders.put("Location", address + redirect));
+            addresses.getAccessAddress().ifPresent(address -> responseHeaders.put(HttpHeader.LOCATION.asString(), address + redirect));
         }
     }
 
     private void sendCompressed() throws IOException {
-        servletResponse.setHeader(HttpHeader.CONTENT_ENCODING.asString(), "gzip");
+        response.getHeaders().remove(HttpHeader.ACCEPT_RANGES.asString());
-        beginSend();
+        response.getHeaders().put(HttpHeader.CONTENT_ENCODING.asString(), "gzip");
-        try (OutputStream out = new GZIPOutputStream(servletResponse.getOutputStream())) {
+
-            send(out);
+        byte[] gzipped = gzip();
+        try (OutputStream out = servletResponse.getOutputStream()) {
+            response.getHeaders().put(HttpHeader.CONTENT_LENGTH.asString(), String.valueOf(gzipped.length));
+            setResponseHeaders();
+
+            servletResponse.setStatus(response.getCode());
+
+            send(out, gzipped);
         }
     }
 
-    private void beginSend() throws IOException {
+    private byte[] gzip() throws IOException {
+        try (ByteArrayOutputStream bufferStream = new ByteArrayOutputStream();
+             GZIPOutputStream gzipStream = new GZIPOutputStream(bufferStream)
+        ) {
+            gzipStream.write(response.getBytes());
+            gzipStream.finish();
+            gzipStream.flush();
+            return bufferStream.toByteArray();
+        }
+    }
+
+    private void beginSend() {
         String length = response.getHeaders().get(HttpHeader.CONTENT_LENGTH.asString());
         if (length == null || "0".equals(length) || response.getCode() == 204 || "HEAD".equals(servletRequest.getMethod())) {
             servletResponse.setHeader(HttpHeader.CONTENT_LENGTH.asString(), null);
@@ -105,8 +133,12 @@ public class JettyResponseSender {
     }
 
     private void send(OutputStream out) throws IOException {
+        send(out, response.getBytes());
+    }
+
+    private void send(OutputStream out, byte[] bytes) throws IOException {
         try (
-                ByteArrayInputStream bis = new ByteArrayInputStream(response.getBytes())
+                ByteArrayInputStream bis = new ByteArrayInputStream(bytes)
         ) {
             byte[] buffer = new byte[2048];
             int count;