Fix bug for FeignException cannot get the correct charset (#1325)

core/src/main/java/feign/FeignException.java

@@ -450,11 +450,11 @@ private static String getResponseBodyPreview(byte[] body, Charset charset) {
     private static Charset getResponseCharset(Map<String, Collection<String>> headers) {
 
       Collection<String> strings = headers.get("content-type");
-      if (strings == null || strings.size() == 0) {
+      if (strings == null || strings.isEmpty()) {
         return null;
       }
 
-      Pattern pattern = Pattern.compile("charset=([^\\s])");
+      Pattern pattern = Pattern.compile(".*charset=([^\\s|^;]+).*");
       Matcher matcher = pattern.matcher(strings.iterator().next());
       if (!matcher.lookingAt()) {
         return null;

core/src/test/java/feign/FeignExceptionTest.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2020 The Feign Authors
+ * Copyright 2012-2021 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -16,7 +16,7 @@
 import org.junit.Test;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
-import java.util.Collections;
+import java.util.*;
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class FeignExceptionTest {
@@ -58,6 +58,58 @@ public void canCreateWithRequestOnly() {
     assertThat(exception.request()).isNotNull();
   }
 
+  @Test
+  public void createFeignExceptionWithCorrectCharsetResponse() {
+    Map<String, Collection<String>> map = new HashMap<>();
+    map.put("connection", new ArrayList<>(Collections.singletonList("keep-alive")));
+    map.put("content-length", new ArrayList<>(Collections.singletonList("100")));
+    map.put("content-type",
+        new ArrayList<>(Collections.singletonList("application/json;charset=UTF-16BE")));
+
+    Request request = Request.create(Request.HttpMethod.GET,
+        "/home", Collections.emptyMap(),
+        "data".getBytes(StandardCharsets.UTF_16BE),
+        StandardCharsets.UTF_16BE,
+        null);
+
+    Response response = Response.builder()
+        .status(400)
+        .body("response".getBytes(StandardCharsets.UTF_16BE))
+        .headers(map)
+        .request(request)
+        .build();
+
+    FeignException exception = FeignException.errorStatus("methodKey", response);
+    assertThat(exception.getMessage())
+        .isEqualTo("[400] during [GET] to [/home] [methodKey]: [response]");
+  }
+
+  @Test
+  public void createFeignExceptionWithErrorCharsetResponse() {
+    Map<String, Collection<String>> map = new HashMap<>();
+    map.put("connection", new ArrayList<>(Collections.singletonList("keep-alive")));
+    map.put("content-length", new ArrayList<>(Collections.singletonList("100")));
+    map.put("content-type",
+        new ArrayList<>(Collections.singletonList("application/json;charset=UTF-8")));
+
+    Request request = Request.create(Request.HttpMethod.GET,
+        "/home", Collections.emptyMap(),
+        "data".getBytes(StandardCharsets.UTF_16BE),
+        StandardCharsets.UTF_16BE,
+        null);
+
+    Response response = Response.builder()
+        .status(400)
+        .body("response".getBytes(StandardCharsets.UTF_16BE))
+        .headers(map)
+        .request(request)
+        .build();
+
+    FeignException exception = FeignException.errorStatus("methodKey", response);
+    assertThat(exception.getMessage())
+        .isNotEqualTo("[400] during [GET] to [/home] [methodKey]: [response]");
+  }
+
   @Test(expected = NullPointerException.class)
   public void nullRequestShouldThrowNPEwThrowable() {
     new Derived(404, "message", null, new Throwable());