Fix bug with posting items to the API

Author: nightowlengineer

src/main/java/engineer/nightowl/sonos/api/resource/BaseResource.java

@@ -13,15 +13,20 @@
 import engineer.nightowl.sonos.api.util.SonosUtilityHelper;
 import org.apache.commons.io.IOUtils;
 import org.apache.http.Header;
-import org.apache.http.client.methods.*;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpDelete;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.client.methods.HttpRequestBase;
+import org.apache.http.client.methods.HttpUriRequest;
 import org.apache.http.client.utils.URIBuilder;
+import org.apache.http.entity.ContentType;
 import org.apache.http.entity.StringEntity;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.UnsupportedEncodingException;
 import java.net.URISyntaxException;
 
 /**
@@ -37,6 +42,7 @@ class BaseResource
             .setSerializationInclusion(JsonInclude.Include.NON_NULL);
     /**
      * Sonos can provide a header describing the response type
+     *
      * @see engineer.nightowl.sonos.api.enums.SonosType
      */
     private static final String SONOS_TYPE_HEADER = "X-Sonos-Type";
@@ -232,8 +238,8 @@ <T, U> T postToApi(final Class<T> returnType, final String token, final String p
             try
             {
                 json = OM.writeValueAsString(content);
-                requestContent = new StringEntity(json);
-            } catch (final JsonProcessingException | UnsupportedEncodingException e)
+                requestContent = new StringEntity(json, ContentType.APPLICATION_JSON);
+            } catch (final JsonProcessingException e)
             {
                 throw new SonosApiClientException("Unable to convert POST request parameters", e);
             }