Use streams when deserializing objects from http response

Author: TDesjardins

src/main/java/com/github/kaklakariada/fritzbox/http/HttpTemplate.java

@@ -94,22 +94,10 @@ private <T> T parse(final Response response, Class<T> resultType) {
         if (!response.isSuccessful()) {
             throw new FritzBoxException("Request failed: " + response);
         }
-        final String body = getBodyAsString(response);
-        if (body.startsWith("HTTP/1.0 500 Internal Server Error")) {
-            throw new FritzBoxException("Request failed: " + body);
-        }
-        if (LOG.isTraceEnabled()) {
-            LOG.trace("Got response {} with body\n'{}'", response, body.trim());
-        }
-        return deserializer.parse(body.trim(), resultType);
-    }
-
-    private String getBodyAsString(final Response response) {
-        try {
-            return response.body().string();
-        } catch (final IOException e) {
-            throw new HttpException("Error getting body from response " + response, e);
+        if (response.code() == 500) {
+            throw new FritzBoxException("Request failed: " + deserializer.getStringFromStream(response.body().byteStream()));
         }
+        return deserializer.parse(response.body().byteStream(), resultType);
     }
 
     private HttpUrl createUrl(String path, QueryParameters parameters) {

src/main/java/com/github/kaklakariada/fritzbox/mapping/Deserializer.java

@@ -17,6 +17,11 @@
  */
 package com.github.kaklakariada.fritzbox.mapping;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.Scanner;
+
 import org.simpleframework.xml.Serializer;
 import org.simpleframework.xml.core.Persister;
 import org.slf4j.Logger;
@@ -38,25 +43,43 @@ public Deserializer() {
         this.xmlSerializer = xmlSerializer;
     }
 
-    public <T> T parse(String data, Class<T> resultType) {
-        if (resultType == String.class) {
-            return resultType.cast(data);
-        }
-        if (resultType == Boolean.class) {
-            return resultType.cast("1".equals(data));
+    public <T> T parse(InputStream data, Class<T> resultType) {
+        try {
+            final T resultObject;
+            if (resultType == String.class
+                    || resultType == Boolean.class
+                    || resultType == Integer.class) {
+                resultObject = parseSimpleType(resultType, data);
+            } else {
+                resultObject = xmlSerializer.read(resultType, data);
+            }
+            LOG.trace("Parsed response: {}", resultObject);
+            return resultObject;
+        } catch (final Exception e) {
+            throw new DeserializerException("Error parsing response body", e);
         }
-        if (resultType == Integer.class) {
-            if (data.isEmpty() || "inval".equals(data)) {
+    }
+
+    private <T> T parseSimpleType(Class<T> resultType, InputStream data) throws IOException {
+        final String string = getStringFromStream(data);
+        if (resultType == String.class) {
+            return resultType.cast(string);
+        } else if (resultType == Boolean.class) {
+            return resultType.cast("1".equals(string));
+        } else if (resultType == Integer.class) {
+            if (string.isEmpty() || "inval".equals(string)) {
                 return null;
             }
-            return resultType.cast(Integer.parseInt(data));
-        }
-        try {
-            final T object = xmlSerializer.read(resultType, data);
-            LOG.trace("Parsed response: {}", object);
-            return object;
-        } catch (final Exception e) {
-            throw new DeserializerException("Error parsing response body '" + data + "'", e);
+            return resultType.cast(Integer.parseInt(string));
         }
+        throw new IOException("Type '" + resultType + "' is not supported: " + string);
     }
+
+    public String getStringFromStream(InputStream data) {
+        final Scanner scanner = new Scanner(data, StandardCharsets.UTF_8.toString());
+        final String string = scanner.next();
+        scanner.close();
+        return string;
+    }
+
 }

src/test/java/com/github/kaklakariada/fritzbox/mapping/DeserializerTest.java

@@ -18,14 +18,14 @@
 package com.github.kaklakariada.fritzbox.mapping;
 
 import static com.github.kaklakariada.fritzbox.assertions.HomeAutomationAssertions.assertThat;
-import static java.util.stream.Collectors.joining;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -110,16 +110,13 @@ void parseDeviceListAllTogetherWithBlind() throws IOException {
     }
 
     DeviceList parseDeviceList(final Path file) throws IOException {
-        final String content = Files.readString(file);
+        final InputStream content = Files.newInputStream(file);
         return new Deserializer().parse(content, DeviceList.class);
     }
 
     @Test
     void parseDeviceStatsFritzDect200() throws IOException {
-        final String fileContent = Files
-                .readAllLines(Paths.get("src/test/resources/FritzOS29/devicestatsFritzDect200.xml"))
-                .stream()
-                .collect(joining("\n"));
+        final InputStream fileContent = Files.newInputStream(Paths.get("src/test/resources/FritzOS29/devicestatsFritzDect200.xml"));
         final DeviceStats stats = new Deserializer().parse(fileContent, DeviceStats.class);
         assertEquals(1, stats.getTemperature().get().getStats().size(), "Temperature has just one statistics Element");
         assertEquals(Double.valueOf(0.1),
@@ -133,8 +130,7 @@ void parseDeviceStatsFritzDect200() throws IOException {
 
     @Test
     void parseSessionInfo() throws IOException {
-        final String fileContent = Files.readAllLines(Paths.get("src/test/resources/sessionInfo.xml")).stream()
-                .collect(joining("\n"));
+        final InputStream fileContent = Files.newInputStream(Paths.get("src/test/resources/sessionInfo.xml"));
         final SessionInfo sessionInfo = new Deserializer().parse(fileContent, SessionInfo.class);
         assertNotNull(sessionInfo.getUsers());
         assertEquals(3, sessionInfo.getUsers().size());