From c770f442c0f20a2d5791304c7071b5e78e7201da Mon Sep 17 00:00:00 2001
From: Martin Ndegwa <mndegwa@ona.io>
Date: Thu, 22 Aug 2024 21:20:05 +0300
Subject: [PATCH] Fix character encoding issue when parsing custom HTTP
 responses

---
 .../plugins/endpoint/BaseEndpoint.java        | 19 +++++++++++++++++++
 .../endpoint/LocationHierarchyEndpoint.java   |  7 ++++---
 .../endpoint/PractitionerDetailEndpoint.java  |  7 ++++---
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/BaseEndpoint.java b/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/BaseEndpoint.java
index ff3c97c..80c0114 100644
--- a/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/BaseEndpoint.java
+++ b/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/BaseEndpoint.java
@@ -1,11 +1,17 @@
 package org.smartregister.fhir.gateway.plugins.endpoint;
 
 import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.nio.charset.StandardCharsets;
 
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.smartregister.fhir.gateway.plugins.RestUtils;
 
 import com.google.fhir.gateway.TokenVerifier;
@@ -14,6 +20,8 @@
 import ca.uhn.fhir.parser.IParser;
 
 public abstract class BaseEndpoint extends HttpServlet {
+    private static final Logger logger = LoggerFactory.getLogger(BaseEndpoint.class);
+
     protected final TokenVerifier tokenVerifier = TokenVerifier.createFromEnvVars();
     protected final FhirContext fhirR4Context = FhirContext.forR4();
     protected final IParser fhirR4JsonParser = fhirR4Context.newJsonParser().setPrettyPrint(true);
@@ -24,4 +32,15 @@ protected void doOptions(HttpServletRequest request, HttpServletResponse respons
     }
 
     protected BaseEndpoint() throws IOException {}
+
+    protected void writeUTF8StringToStream(OutputStream fileOutputStream, String content) {
+        try (OutputStreamWriter outputStreamWriter =
+                        new OutputStreamWriter(fileOutputStream, StandardCharsets.UTF_8);
+                PrintWriter printWriter = new PrintWriter(outputStreamWriter)) {
+            printWriter.println(content);
+            printWriter.flush();
+        } catch (IOException e) {
+            logger.error(e.getMessage());
+        }
+    }
 }
diff --git a/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/LocationHierarchyEndpoint.java b/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/LocationHierarchyEndpoint.java
index 216004a..b0c79f9 100644
--- a/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/LocationHierarchyEndpoint.java
+++ b/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/LocationHierarchyEndpoint.java
@@ -57,15 +57,16 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
                 resultContent = fhirR4JsonParser.encodeResourceToString(resultBundle);
             }
             response.setContentType("application/json");
-            response.getOutputStream().print(resultContent);
+            writeUTF8StringToStream(response.getOutputStream(), resultContent);
             response.setStatus(HttpStatus.SC_OK);
         } catch (AuthenticationException authenticationException) {
             response.setContentType("application/json");
-            response.getOutputStream().print(authenticationException.getMessage());
+            writeUTF8StringToStream(
+                    response.getOutputStream(), authenticationException.getMessage());
             response.setStatus(authenticationException.getStatusCode());
         } catch (Exception exception) {
             response.setContentType("application/json");
-            response.getOutputStream().print(exception.getMessage());
+            writeUTF8StringToStream(response.getOutputStream(), exception.getMessage());
             response.setStatus(HttpStatus.SC_INTERNAL_SERVER_ERROR);
         }
     }
diff --git a/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/PractitionerDetailEndpoint.java b/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/PractitionerDetailEndpoint.java
index a9f1040..3f17417 100755
--- a/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/PractitionerDetailEndpoint.java
+++ b/plugins/src/main/java/org/smartregister/fhir/gateway/plugins/endpoint/PractitionerDetailEndpoint.java
@@ -53,15 +53,16 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
             }
 
             response.setContentType("application/json");
-            response.getOutputStream().print(resultContent);
+            writeUTF8StringToStream(response.getOutputStream(), resultContent);
             response.setStatus(HttpStatus.SC_OK);
         } catch (AuthenticationException authenticationException) {
             response.setContentType("application/json");
-            response.getOutputStream().print(authenticationException.getMessage());
+            writeUTF8StringToStream(
+                    response.getOutputStream(), authenticationException.getMessage());
             response.setStatus(authenticationException.getStatusCode());
         } catch (Exception exception) {
             response.setContentType("application/json");
-            response.getOutputStream().print(exception.getMessage());
+            writeUTF8StringToStream(response.getOutputStream(), exception.getMessage());
             response.setStatus(HttpStatus.SC_INTERNAL_SERVER_ERROR);
         }
     }