Merge pull request #54 from SentryMan/exception-handling

Add retry exception handler

Author: rbygrave

client/src/main/java/io/avaje/http/client/DHttpClientRequestWithRetry.java

@@ -22,14 +22,34 @@ final class DHttpClientRequestWithRetry extends DHttpClientRequest {
   @Override
   protected <T> HttpResponse<T> performSend(HttpResponse.BodyHandler<T> responseHandler) {
     HttpResponse<T> res;
-    res = super.performSend(responseHandler);
-    if (res.statusCode() < 300) {
-      return res;
-    }
-    while (retryHandler.isRetry(retryCount++, res)) {
-      res = super.performSend(responseHandler);
+    HttpException ex;
+
+    do {
+      try {
+        res = super.performSend(responseHandler);
+        ex = null;
+      } catch (final HttpException e) {
+        ex = e;
+        res = null;
+      }
+      if (res != null && res.statusCode() < 300) {
+        return res;
+      }
+      retryCount++;
+    } while (retry(res, ex));
+
+    if (res == null && ex != null) {
+      throw ex;
     }
+
     return res;
   }
 
+  protected boolean retry(HttpResponse<?> res, HttpException ex) {
+
+    if (res != null) {
+      return retryHandler.isRetry(retryCount, res);
+    }
+    return retryHandler.isExceptionRetry(retryCount, ex);
+  }
 }

client/src/main/java/io/avaje/http/client/HttpException.java

@@ -91,28 +91,37 @@ public HttpException(int statusCode, Throwable cause) {
   }
 
   /**
-   * Return the response body content as a bean
+   * Return the response body content as a bean, or else null if body content doesn't exist.
    *
    * @param cls The type of bean to convert the response to
    * @return The response as a bean
    */
   public <T> T bean(Class<T> cls) {
+    if (httpResponse == null) {
+      return null;
+    }
     final BodyContent body = context.readErrorContent(responseAsBytes, httpResponse);
     return context.readBean(cls, body);
   }
 
   /**
-   * Return the response body content as a UTF8 string.
+   * Return the response body content as a UTF8 string, or else null if body content doesn't exist.
    */
   public String bodyAsString() {
+    if (httpResponse == null) {
+      return null;
+    }
     final BodyContent body = context.readErrorContent(responseAsBytes, httpResponse);
     return new String(body.content(), StandardCharsets.UTF_8);
   }
 
-  /**
-   * Return the response body content as raw bytes.
+  /** 
+   * Return the response body content as raw bytes, or else null if body content doesn't exist.
    */
   public byte[] bodyAsBytes() {
+    if (httpResponse == null) {
+      return null;
+    }
     final BodyContent body = context.readErrorContent(responseAsBytes, httpResponse);
     return body.content();
   }

client/src/main/java/io/avaje/http/client/RetryHandler.java

@@ -11,9 +11,19 @@ public interface RetryHandler {
    * Return true if the request should be retried.
    *
    * @param retryCount The number of retry attempts already executed
-   * @param response   The HTTP response
+   * @param response The HTTP response
    * @return True if the request should be retried or false if not
    */
   boolean isRetry(int retryCount, HttpResponse<?> response);
 
+  /**
+   * Return true if the request should be retried.
+   *
+   * @param retryCount The number of retry attempts already executed
+   * @param exception The Wrapped Error thrown by the underlying Http Client
+   * @return True if the request should be retried or false if not
+   */
+  default boolean isExceptionRetry(int retryCount, HttpException exception) {
+    throw exception;
+  }
 }