fix issue 911

src/main/java/spark/http/matching/Body.java

@@ -32,6 +32,9 @@ final class Body {
 
     private Object content;
 
+    //CS304 Issue link: https://github.com/perwendel/spark/issues/911
+    private final Configuration configuration = Configuration.getConfiguration();
+
     public static Body create() {
         return new Body();
     }
@@ -62,7 +65,9 @@ public void serializeTo(HttpServletResponse httpResponse,
 
         if (!httpResponse.isCommitted()) {
             if (httpResponse.getContentType() == null) {
-                httpResponse.setContentType("text/html; charset=utf-8");
+                //CS304 Issue link: https://github.com/perwendel/spark/issues/911
+                String type = configuration.getDefaultContentType();
+                httpResponse.setContentType(type);
             }
 
             // Check if GZIP is wanted/accepted and in that case handle that

src/main/java/spark/http/matching/Configuration.java

@@ -0,0 +1,23 @@
+package spark.http.matching;
+
+//CS304 Issue link: https://github.com/perwendel/spark/issues/911
+public class Configuration {
+    private String defaultContentType;
+    private static final Configuration configuration = new Configuration();
+
+    private Configuration() {
+        defaultContentType = "text/html; charset=utf-8";
+    }
+
+    public static Configuration getConfiguration(){
+        return configuration;
+    }
+
+    public void setDefaultContentType(String type) {
+        defaultContentType = type;
+    }
+
+    public String getDefaultContentType() {
+        return defaultContentType;
+    }
+}

src/test/java/spark/issue911Test.java

@@ -0,0 +1,49 @@
+package spark;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.Before;
+import spark.http.matching.Configuration;
+
+import static spark.Spark.*;
+
+public class issue911Test {
+    Configuration configuration;
+
+    //CS304 Issue link: https://github.com/perwendel/spark/issues/911
+    @Before
+    public void init(){
+        configuration = Configuration.getConfiguration();
+    }
+
+    //CS304 Issue link: https://github.com/perwendel/spark/issues/911
+    @Test
+    public void TestResponseDefaultContentType() throws Exception {
+        get("/hello", (request, response) -> {
+            Assert.assertEquals("text/html; charset=utf-8", response.type());
+            return "Hello World!";
+        });
+    }
+
+    //CS304 Issue link: https://github.com/perwendel/spark/issues/911
+    @Test
+    public void TestResponseTypeModifiedByBefore() throws Exception {
+        before("/hello", (request, response) -> response.type("application/json"));
+        get("/hello", (request, response) -> {
+            Assert.assertEquals("text/html; charset=utf-8", configuration.getDefaultContentType());
+            Assert.assertEquals("application/json", response.type());
+            return "Hello World!";
+        });
+    }
+
+    //CS304 Issue link: https://github.com/perwendel/spark/issues/911
+    @Test
+    public void TestSetDefaultContentType() throws Exception {
+        configuration.setDefaultContentType("text/html");
+        get("/hello", (request, response) -> {
+            Assert.assertEquals("text/html",configuration.getDefaultContentType());
+            Assert.assertEquals("text/html", response.type());
+            return "Hello World!";
+        });
+    }
+}