From d9d83179e293503a99e1f4ed6d69ab3b62e10fd9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mathias=20R=C3=BChle?= <math2306@hotmail.com>
Date: Wed, 3 Jan 2024 16:25:34 +0100
Subject: [PATCH] Wrap HTTP Exceptions in Flare Client with Additional
 Information

---
 .../flare/FlareWebserviceClientImpl.java      | 23 ++++++++++++++-----
 .../flare/FlareWebserviceClientImplTest.java  | 22 ++++++++++++++++--
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/feasibility-dsf-process/src/main/java/de/medizininformatik_initiative/feasibility_dsf_process/client/flare/FlareWebserviceClientImpl.java b/feasibility-dsf-process/src/main/java/de/medizininformatik_initiative/feasibility_dsf_process/client/flare/FlareWebserviceClientImpl.java
index de7cf51..fb0a5ac 100644
--- a/feasibility-dsf-process/src/main/java/de/medizininformatik_initiative/feasibility_dsf_process/client/flare/FlareWebserviceClientImpl.java
+++ b/feasibility-dsf-process/src/main/java/de/medizininformatik_initiative/feasibility_dsf_process/client/flare/FlareWebserviceClientImpl.java
@@ -3,6 +3,7 @@
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
+import org.apache.http.client.methods.HttpUriRequest;
 import org.apache.http.entity.ByteArrayEntity;
 import org.apache.http.impl.client.BasicResponseHandler;
 import org.apache.http.message.BasicHeader;
@@ -11,6 +12,7 @@
 import java.net.URI;
 
 import static ca.uhn.fhir.rest.api.Constants.HEADER_CONTENT_TYPE;
+import static java.lang.String.format;
 
 /**
  * Client for communicating with a Flare instance.
@@ -31,19 +33,28 @@ public int requestFeasibility(byte[] structuredQuery) throws IOException, Interr
         req.setEntity(new ByteArrayEntity(structuredQuery));
         req.setHeader(new BasicHeader(HEADER_CONTENT_TYPE, "application/sq+json"));
 
-        var response = httpClient.execute(req, new BasicResponseHandler());
+        var response = sendRequest(req);
 
         return Integer.parseInt(response);
     }
 
-    private URI resolve(String path) {
-        return flareBaseUrl.resolve((flareBaseUrl.getPath() + path).replaceAll("//", "/"));
-    }
-
     @Override
     public void testConnection() throws IOException {
         var req = new HttpGet(resolve("/cache/stats"));
 
-        httpClient.execute(req, new BasicResponseHandler());
+        sendRequest(req);
+    }
+
+    private URI resolve(String path) {
+        return flareBaseUrl.resolve((flareBaseUrl.getPath() + path).replaceAll("//", "/"));
+    }
+
+    private String sendRequest(HttpUriRequest req) throws IOException {
+        try {
+            return httpClient.execute(req, new BasicResponseHandler());
+        } catch (IOException e) {
+            throw new IOException(
+                    format("Error sending %s request to flare webservice url '%s'.", req.getMethod(), req.getURI()), e);
+        }
     }
 }
diff --git a/feasibility-dsf-process/src/test/java/de/medizininformatik_initiative/feasibility_dsf_process/client/flare/FlareWebserviceClientImplTest.java b/feasibility-dsf-process/src/test/java/de/medizininformatik_initiative/feasibility_dsf_process/client/flare/FlareWebserviceClientImplTest.java
index 8043878..b633e7f 100644
--- a/feasibility-dsf-process/src/test/java/de/medizininformatik_initiative/feasibility_dsf_process/client/flare/FlareWebserviceClientImplTest.java
+++ b/feasibility-dsf-process/src/test/java/de/medizininformatik_initiative/feasibility_dsf_process/client/flare/FlareWebserviceClientImplTest.java
@@ -18,6 +18,8 @@
 import java.net.URISyntaxException;
 import java.time.Duration;
 
+import static jakarta.ws.rs.HttpMethod.POST;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -28,14 +30,16 @@
 @ExtendWith(MockitoExtension.class)
 public class FlareWebserviceClientImplTest {
 
-    private org.apache.http.client.HttpClient httpClient;
+    private HttpClient httpClient;
+    private URI flareBaseUrl;
     private FlareWebserviceClient flareWebserviceClient;
     @Captor ArgumentCaptor<HttpPost> postCaptor;
 
     @BeforeEach
     public void setUp() throws URISyntaxException {
         httpClient = mock(HttpClient.class);
-        flareWebserviceClient = new FlareWebserviceClientImpl(httpClient, new URI("http://localhost:5000/"));
+        flareBaseUrl = new URI("http://localhost:5000/");
+        flareWebserviceClient = new FlareWebserviceClientImpl(httpClient, flareBaseUrl);
     }
 
     @Test
@@ -134,4 +138,18 @@ void testOtherEvaluationStrategyFails() throws Exception {
 
         assertEquals("EVALUATION_STRATEGY is not set to 'structured-query'.", e.getMessage());
     }
+
+    @Test
+    void sendErrorGetsRethrownWithAdditionalInformation() throws Exception {
+        byte[] structuredQuery = "foo".getBytes();
+        IOException error = new IOException("error-151930");
+        when(httpClient.execute(any(HttpPost.class), any(BasicResponseHandler.class))).thenThrow(error);
+
+        assertThatThrownBy(() -> {
+            flareWebserviceClient.requestFeasibility(structuredQuery);
+        })
+            .hasMessage("Error sending %s request to flare webservice url '%s'.", POST,
+                    flareBaseUrl.resolve("/query/execute"))
+            .hasCause(error);
+    }
 }