Issue #1606 Customize the length of the body in FeignException builder (

#1767)

Co-authored-by: Witalij Berdinskich <radio_rogal@keemail.me>
Co-authored-by: Marvin Froeder <velo@users.noreply.github.com>

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

@@ -37,10 +37,10 @@ public class FeignException extends RuntimeException {
   private static final String EXCEPTION_MESSAGE_TEMPLATE_NULL_REQUEST =
       "request should not be null";
   private static final long serialVersionUID = 0;
-  private int status;
+  private final int status;
   private byte[] responseBody;
   private Map<String, Collection<String>> responseHeaders;
-  private Request request;
+  private final Request request;
 
   protected FeignException(int status, String message, Throwable cause) {
     super(message, cause);
@@ -183,6 +183,11 @@ static FeignException errorReading(Request request, Response response, IOExcepti
   }
 
   public static FeignException errorStatus(String methodKey, Response response) {
+    return errorStatus(methodKey, response, null, null);
+  }
+
+  public static FeignException errorStatus(
+      String methodKey, Response response, Integer maxBodyBytesLength, Integer maxBodyCharsLength) {
 
     byte[] body = {};
     try {
@@ -196,6 +201,8 @@ public static FeignException errorStatus(String methodKey, Response response) {
         new FeignExceptionMessageBuilder()
             .withResponse(response)
             .withMethodKey(methodKey)
+            .withMaxBodyBytesLength(maxBodyBytesLength)
+            .withMaxBodyCharsLength(maxBodyCharsLength)
             .withBody(body)
             .build();
 
@@ -434,6 +441,8 @@ private static class FeignExceptionMessageBuilder {
 
     private byte[] body;
     private String methodKey;
+    private Integer maxBodyBytesLength;
+    private Integer maxBodyCharsLength;
 
     public FeignExceptionMessageBuilder withResponse(Response response) {
       this.response = response;
@@ -450,9 +459,25 @@ public FeignExceptionMessageBuilder withMethodKey(String methodKey) {
       return this;
     }
 
+    public FeignExceptionMessageBuilder withMaxBodyBytesLength(Integer length) {
+      this.maxBodyBytesLength = length;
+      return this;
+    }
+
+    public FeignExceptionMessageBuilder withMaxBodyCharsLength(Integer length) {
+      this.maxBodyCharsLength = length;
+      return this;
+    }
+
     public String build() {
       StringBuilder result = new StringBuilder();
 
+      if (maxBodyBytesLength == null) {
+        maxBodyBytesLength = MAX_BODY_BYTES_LENGTH;
+      }
+      if (maxBodyCharsLength == null) {
+        maxBodyCharsLength = MAX_BODY_CHARS_LENGTH;
+      }
       if (response.reason() != null) {
         result.append(format("[%d %s]", response.status(), response.reason()));
       } else {
@@ -468,32 +493,32 @@ public String build() {
       return result.toString();
     }
 
-    private static String getBodyAsString(byte[] body, Map<String, Collection<String>> headers) {
+    private String getBodyAsString(byte[] body, Map<String, Collection<String>> headers) {
       Charset charset = getResponseCharset(headers);
       if (charset == null) {
         charset = Util.UTF_8;
       }
       return getResponseBody(body, charset);
     }
 
-    private static String getResponseBody(byte[] body, Charset charset) {
-      if (body.length < MAX_BODY_BYTES_LENGTH) {
+    private String getResponseBody(byte[] body, Charset charset) {
+      if (body.length < maxBodyBytesLength) {
         return new String(body, charset);
       }
       return getResponseBodyPreview(body, charset);
     }
 
-    private static String getResponseBodyPreview(byte[] body, Charset charset) {
+    private String getResponseBodyPreview(byte[] body, Charset charset) {
       try {
         Reader reader = new InputStreamReader(new ByteArrayInputStream(body), charset);
-        CharBuffer result = CharBuffer.allocate(MAX_BODY_CHARS_LENGTH);
+        CharBuffer result = CharBuffer.allocate(maxBodyCharsLength);
 
         reader.read(result);
         reader.close();
         ((Buffer) result).flip();
-        return result.toString() + "... (" + body.length + " bytes)";
+        return result + "... (" + body.length + " bytes)";
       } catch (IOException e) {
-        return e.toString() + ", failed to parse response";
+        return e + ", failed to parse response";
       }
     }
 

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

@@ -164,6 +164,54 @@ public void canGetResponseHeadersFromException() {
             });
   }
 
+  @Test
+  public void lengthOfBodyExceptionTest() {
+    String bigResponse =
+        "I love a storm in early May\n"
+            + "When springtime’s boisterous, firstborn thunder\n"
+            + "Over the sky will gaily wander\n"
+            + "And growl and roar as though in play.\n"
+            + "\n"
+            + "A peal, another — gleeful, cheering…\n"
+            + "Rain, raindust… On the trees, behold!-\n"
+            + "The drops hang, each a long pearl earring;\n"
+            + "Bright sunshine paints the thin threads gold.\n"
+            + "\n"
+            + "A stream downhill goes rushing reckless,\n"
+            + "And in the woods the birds rejoice.\n"
+            + "Din. Clamour. Noise. All nature echoes\n"
+            + "The thunder’s youthful, merry voice.\n"
+            + "\n"
+            + "You’ll say: ‘Tis laughing, carefree Hebe —\n"
+            + "She fed her father’s eagle, and\n"
+            + "The Storm Cup brimming with a seething\n"
+            + "And bubbling wine dropped from her hand";
+
+    Request request =
+        Request.create(
+            Request.HttpMethod.GET,
+            "/home",
+            Collections.emptyMap(),
+            "data".getBytes(StandardCharsets.UTF_8),
+            StandardCharsets.UTF_8,
+            null);
+
+    Response response =
+        Response.builder()
+            .status(400)
+            .request(request)
+            .body(bigResponse, StandardCharsets.UTF_8)
+            .build();
+
+    FeignException defaultException = FeignException.errorStatus("methodKey", response);
+    assertThat(defaultException.getMessage().length()).isLessThan(bigResponse.length());
+
+    FeignException customLengthBodyException =
+        FeignException.errorStatus("methodKey", response, 4000, 2000);
+    assertThat(customLengthBodyException.getMessage().length())
+        .isGreaterThanOrEqualTo(bigResponse.length());
+  }
+
   @Test(expected = NullPointerException.class)
   public void nullRequestShouldThrowNPEwThrowable() {
     new Derived(404, "message", null, new Throwable());