Fix URL concatenation

Fix Patreon#40

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.4.3
+## Fixed
+* URL concatenation on the different versions of the JDK and upstream projects' dependencies
+
 # 0.4.2
 ## Fixed
 * GRANT_TYPE_TOKEN_REFRESH now has the correct value

pom.xml

@@ -78,7 +78,7 @@ and https://issues.apache.org/jira/browse/SUREFIRE-1588 -->
 
     <groupId>com.patreon</groupId>
     <artifactId>patreon</artifactId>
-    <version>0.4.2</version>
+    <version>0.4.3</version>
 
     <name>${project.groupId}:${project.artifactId}</name>
     <description>Interact with the Patreon API via OAuth</description>

src/main/java/com/patreon/resources/RequestUtil.java

@@ -3,6 +3,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
 import java.net.URL;
 
 import static com.patreon.PatreonAPI.BASE_URI;
@@ -13,8 +14,7 @@
 public class RequestUtil {
 
   public InputStream request(String pathSuffix, String accessToken) throws IOException {
-      String prefix = BASE_URI + "/api/oauth2/api/";
-      URL url = new URL(prefix.concat(pathSuffix));
+      URL url = buildUrl(pathSuffix);
       HttpURLConnection connection = (HttpURLConnection) url.openConnection();
       connection.setRequestProperty("Authorization", "Bearer ".concat(accessToken));
       connection.setRequestProperty("User-Agent",
@@ -26,6 +26,16 @@ public InputStream request(String pathSuffix, String accessToken) throws IOExcep
     return connection.getInputStream();
   }
 
+  private URL buildUrl(String pathSuffix) throws MalformedURLException {
+    if (pathSuffix.startsWith("/")) {
+      pathSuffix = pathSuffix.substring(1, pathSuffix.length());
+    }
+
+    String prefix = BASE_URI + "/api/oauth2/api/";
+    URL url = new URL(prefix.concat(pathSuffix));
+    return url;
+  }
+
   private String getVersion() throws IOException {
     InputStream resourceAsStream = this.getClass().getResourceAsStream("/version.properties");
     java.util.Properties prop = new java.util.Properties();