diff --git a/pom.xml b/pom.xml
index 9ea3b39..f2eff55 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>xyz.etztech</groupId>
     <artifactId>plugin-api</artifactId>
-    <version>1.0.6</version>
+    <version>1.0.7</version>
     <build>
         <plugins>
             <plugin>
@@ -30,12 +30,12 @@
         <dependency>
             <groupId>com.zaxxer</groupId>
             <artifactId>HikariCP</artifactId>
-            <version>2.6.1</version>
+            <version>3.4.5</version>
         </dependency>
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
-            <version>1.4.197</version>
+            <version>1.4.200</version>
         </dependency>
     </dependencies>
 
diff --git a/src/main/java/xyz/etztech/core/db/DataSource.java b/src/main/java/xyz/etztech/core/db/DataSource.java
index 2e1216e..bdb32e0 100644
--- a/src/main/java/xyz/etztech/core/db/DataSource.java
+++ b/src/main/java/xyz/etztech/core/db/DataSource.java
@@ -11,13 +11,13 @@ import java.sql.SQLException;
  * A class to initialize an H2 database and retrieve connections
  */
 public class DataSource {
-    private HikariConfig config = new HikariConfig();
-    private HikariDataSource dataSource;
+    private final HikariDataSource dataSource;
 
     /** Create a data source for a plugin
      * @param plugin The plugin using this database. Used for creation purposes.
      */
     public DataSource(JavaPlugin plugin) {
+        HikariConfig config = new HikariConfig();
         config.setJdbcUrl("jdbc:h2:" + plugin.getDataFolder().getAbsolutePath() + "/" + plugin.getName().toLowerCase());
         config.setDriverClassName("org.h2.Driver");
         dataSource = new HikariDataSource(config);
diff --git a/src/main/java/xyz/etztech/core/web/MultipartUtility.java b/src/main/java/xyz/etztech/core/web/MultipartUtility.java
index 7da290a..684d98f 100644
--- a/src/main/java/xyz/etztech/core/web/MultipartUtility.java
+++ b/src/main/java/xyz/etztech/core/web/MultipartUtility.java
@@ -21,10 +21,10 @@ import java.util.List;
 public class MultipartUtility {
     private final String boundary;
     private static final String LINE_FEED = "\r\n";
-    private HttpURLConnection httpConn;
-    private String charset;
-    private OutputStream outputStream;
-    private PrintWriter writer;
+    private final HttpURLConnection httpConn;
+    private final String charset;
+    private final OutputStream outputStream;
+    private final PrintWriter writer;
 
     /**
      * This constructor initializes a new HTTP POST request where content type
@@ -59,10 +59,10 @@ public class MultipartUtility {
      * @param value field value
      */
     public void addFormField(String name, String value) {
-        writer.append("--" + boundary).append(LINE_FEED);
-        writer.append("Content-Disposition: form-data; name=\"" + name + "\"")
+        writer.append("--").append(boundary).append(LINE_FEED);
+        writer.append("Content-Disposition: form-data; name=\"").append(name).append("\"")
                 .append(LINE_FEED);
-        writer.append("Content-Type: text/plain; charset=" + charset).append(
+        writer.append("Content-Type: text/plain; charset=").append(charset).append(
                 LINE_FEED);
         writer.append(LINE_FEED);
         writer.append(value).append(LINE_FEED);
@@ -78,14 +78,10 @@ public class MultipartUtility {
     public void addFilePart(String fieldName, File uploadFile)
             throws IOException {
         String fileName = uploadFile.getName();
-        writer.append("--" + boundary).append(LINE_FEED);
-        writer.append(
-                "Content-Disposition: form-data; name=\"" + fieldName
-                        + "\"; filename=\"" + fileName + "\"")
+        writer.append("--").append(boundary).append(LINE_FEED);
+        writer.append("Content-Disposition: form-data; name=\"").append(fieldName).append("\"; filename=\"").append(fileName).append("\"")
                 .append(LINE_FEED);
-        writer.append(
-                "Content-Type: "
-                        + URLConnection.guessContentTypeFromName(fileName))
+        writer.append("Content-Type: ").append(URLConnection.guessContentTypeFromName(fileName))
                 .append(LINE_FEED);
         writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED);
         writer.append(LINE_FEED);
@@ -110,7 +106,7 @@ public class MultipartUtility {
      * @param value - value of the header field
      */
     public void addHeaderField(String name, String value) {
-        writer.append(name + ": " + value).append(LINE_FEED);
+        writer.append(name).append(": ").append(value).append(LINE_FEED);
         writer.flush();
     }
 
@@ -123,7 +119,7 @@ public class MultipartUtility {
         StringBuilder response = new StringBuilder();
 
         //writer.append(LINE_FEED).flush();
-        writer.append("--" + boundary + "--").append(LINE_FEED);
+        writer.append("--").append(boundary).append("--").append(LINE_FEED);
         writer.close();
 
         // checks server's status code first
diff --git a/src/main/java/xyz/etztech/core/web/Response.java b/src/main/java/xyz/etztech/core/web/Response.java
index 2fff89e..0167ab8 100644
--- a/src/main/java/xyz/etztech/core/web/Response.java
+++ b/src/main/java/xyz/etztech/core/web/Response.java
@@ -18,7 +18,7 @@ public class Response {
     private Boolean status;
     private String message;
 
-    private static Logger log = Logger.getLogger("Minecraft");
+    private static final Logger log = Logger.getLogger("Minecraft");
 
     /**
      * @param httpResponse A JSON array e.g. multiple results from one call