ISSUE-466 # Handle unknown-length empty HTTP responses

core/src/main/java/org/jsmart/zerocode/core/httpclient/BasicHttpClient.java

@@ -1,5 +1,6 @@
 package org.jsmart.zerocode.core.httpclient;
 
+import java.io.EOFException;
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.nio.charset.Charset;
@@ -186,14 +187,30 @@ public Response handleResponse(CloseableHttpResponse httpResponse) throws IOExce
      */
     public Response createCharsetResponse(CloseableHttpResponse httpResponse) throws IOException {
         HttpEntity entity = httpResponse.getEntity();
-        Charset charset = ContentType.getOrDefault(httpResponse.getEntity()).getCharset();
+        Charset charset = entity == null ? null : ContentType.getOrDefault(entity).getCharset();
         charset = (charset == null) ? Charset.defaultCharset() : charset;
         return Response
                 .status(httpResponse.getStatusLine().getStatusCode())
-                .entity(entity != null ? IOUtils.toString(entity.getContent(), charset) : null)
+                .entity(readResponseEntity(entity, charset))
                 .build();
     }
 
+    private String readResponseEntity(HttpEntity entity, Charset charset) throws IOException {
+        if (entity == null || entity.getContentLength() == 0) {
+            return null;
+        }
+
+        try {
+            return IOUtils.toString(entity.getContent(), charset);
+        } catch (EOFException ex) {
+            if (entity.getContentLength() < 0) {
+                LOGGER.warn("Received EOF while reading response body with unknown content length. Treating body as empty.");
+                return null;
+            }
+            throw ex;
+        }
+    }
+
     /**
      * If(optionally) query parameters was sent as a JSON in the request below, this gets available to this method
      * for processing them with the url.

core/src/test/java/org/jsmart/zerocode/core/httpclient/BasicHttpClientTest.java

@@ -2,13 +2,17 @@
 
 import com.github.tomakehurst.wiremock.client.WireMock;
 import com.github.tomakehurst.wiremock.junit.WireMockRule;
+import java.io.EOFException;
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
+import org.apache.http.Header;
+import org.apache.http.HttpEntity;
+import org.apache.http.StatusLine;
 import org.apache.http.client.methods.CloseableHttpResponse;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.RequestBuilder;
@@ -28,6 +32,8 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.Is.is;
 import static org.hamcrest.core.IsNot.not;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 public class BasicHttpClientTest {
     private BasicHttpClient basicHttpClient;
@@ -216,4 +222,23 @@ public void willMockDefaultResponseEncoding() throws Exception {
         final String responseBodyActual = (String) basicHttpClient.handleResponse(closeableHttpResponse).getEntity();
         assertThat(responseBodyActual, CoreMatchers.is(response));
     }
-}
+
+    @Test
+    public void willHandleUnknownLengthEmptyResponse() throws Exception {
+        CloseableHttpResponse closeableHttpResponse = mock(CloseableHttpResponse.class);
+        StatusLine statusLine = mock(StatusLine.class);
+        HttpEntity entity = mock(HttpEntity.class);
+
+        when(closeableHttpResponse.getStatusLine()).thenReturn(statusLine);
+        when(closeableHttpResponse.getEntity()).thenReturn(entity);
+        when(closeableHttpResponse.getAllHeaders()).thenReturn(new Header[0]);
+        when(statusLine.getStatusCode()).thenReturn(401);
+        when(entity.getContentLength()).thenReturn(-1L);
+        when(entity.getContent()).thenThrow(new EOFException());
+
+        javax.ws.rs.core.Response handledResponse = basicHttpClient.handleResponse(closeableHttpResponse);
+
+        assertThat(handledResponse.getStatus(), is(401));
+        assertThat(handledResponse.getEntity(), is((Object) null));
+    }
+}