fix: Response.charset does not support RFC 7231 compliant Content-Type headers using quotation marks as application/json; charset="utf-8" (#2444)

Co-authored-by: Stefan Vitz (C804185) <stefan.vitz@sanitas.com>
Co-authored-by: Marvin <velo@users.noreply.github.com>

Author: 3 people

core/src/main/java/feign/Response.java

@@ -168,9 +168,9 @@ public int status() {
   }
 
   /**
-   * Nullable and not set when using http/2
-   *
-   * <p>See https://github.com/http2/http2-spec/issues/202
+   * Nullable and not set when using http/2 See <a
+   * href="/http2/http2-spec/issues/202">...</a> See <a
+   * href="https://github.com/http2/http2-spec/issues/202">...</a>
    */
   public String reason() {
     return reason;
@@ -200,6 +200,12 @@ public ProtocolVersion protocolVersion() {
     return protocolVersion;
   }
 
+  /**
+   * Returns a charset object based on the requests content type. Defaults to UTF-8 See <a
+   * href="https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.3">rfc7231 - Accept-Charset</a>
+   * See <a href="https://datatracker.ietf.org/doc/html/rfc7231#section-3.1.1.1">rfc7231 - Media
+   * Type</a>
+   */
   public Charset charset() {
 
     Collection<String> contentTypeHeaders = headers().get("Content-Type");
@@ -210,7 +216,8 @@ public Charset charset() {
         if (contentTypeParmeters.length > 1) {
           String[] charsetParts = contentTypeParmeters[1].split("=");
           if (charsetParts.length == 2 && "charset".equalsIgnoreCase(charsetParts[0].trim())) {
-            return Charset.forName(charsetParts[1]);
+            String charsetString = charsetParts[1].replaceAll("\"", "");
+            return Charset.forName(charsetString);
           }
         }
       }
@@ -309,7 +316,7 @@ public Reader asReader() {
     }
 
     @Override
-    public Reader asReader(Charset charset) throws IOException {
+    public Reader asReader(Charset charset) {
       checkNotNull(charset, "charset should not be null");
       return new InputStreamReader(inputStream, charset);
     }
@@ -354,23 +361,23 @@ public boolean isRepeatable() {
     }
 
     @Override
-    public InputStream asInputStream() throws IOException {
+    public InputStream asInputStream() {
       return new ByteArrayInputStream(data);
     }
 
     @SuppressWarnings("deprecation")
     @Override
-    public Reader asReader() throws IOException {
+    public Reader asReader() {
       return new InputStreamReader(asInputStream(), UTF_8);
     }
 
     @Override
-    public Reader asReader(Charset charset) throws IOException {
+    public Reader asReader(Charset charset) {
       checkNotNull(charset, "charset should not be null");
       return new InputStreamReader(asInputStream(), charset);
     }
 
     @Override
-    public void close() throws IOException {}
+    public void close() {}
   }
 }

core/src/test/java/feign/ResponseTest.java

@@ -69,6 +69,22 @@ void canAccessHeadersCaseInsensitively() {
             });
   }
 
+  @Test
+  void charsetSupportsMediaTypesWithQuotedCharset() {
+    Map<String, Collection<String>> headersMap = new LinkedHashMap<>();
+    List<String> valueList = Collections.singletonList("application/json; charset=\"utf-8\"");
+    headersMap.put("Content-Type", valueList);
+    Response response =
+        Response.builder()
+            .status(200)
+            .headers(headersMap)
+            .request(
+                Request.create(HttpMethod.GET, "/api", Collections.emptyMap(), null, Util.UTF_8))
+            .body(new byte[0])
+            .build();
+    assertThat(response.charset()).isEqualTo(Util.UTF_8);
+  }
+
   @Test
   void headerValuesWithSameNameOnlyVaryingInCaseAreMerged() {
     Map<String, Collection<String>> headersMap = new LinkedHashMap<>();