[BKNDLSS-24972]: Add upload file method for Java sdk (#504)

* [BKNDLSS-24972]: Add upload file method for Java sdk

* [BKNDLSS-24972]: Improve async method

Co-authored-by: Vladimir Yalovy <[email protected]>

Author: JoeSilentJoe

src/com/backendless/Files.java

@@ -72,6 +72,61 @@ static Files getInstance()
     return instance;
   }
 
+  public BackendlessFile upload( String urlToFile, String backendlessPath )
+  {
+    return upload( urlToFile, backendlessPath, false );
+  }
+
+  public BackendlessFile upload( String urlToFile, String backendlessPath, boolean overwrite )
+  {
+    if( urlToFile == null || urlToFile.isEmpty() )
+      throw new NullPointerException( ExceptionMessage.NULL_URL_TO_FILE );
+
+    if( backendlessPath == null )
+      throw new NullPointerException( ExceptionMessage.NULL_PATH );
+
+    final String resultURL = Invoker.invokeSync( FILE_MANAGER_SERVER_ALIAS, "upload", new Object[] { urlToFile, backendlessPath, overwrite } );
+    return new BackendlessFile( resultURL );
+  }
+
+  public void upload( String urlToFile, String backendlessPath, AsyncCallback<BackendlessFile> responder )
+  {
+    upload( urlToFile, backendlessPath, false, responder );
+  }
+
+  public void upload( String urlToFile, String backendlessPath, boolean overwrite, final AsyncCallback<BackendlessFile> responder )
+  {
+    try
+    {
+      if( urlToFile == null || urlToFile.isEmpty() )
+        throw new NullPointerException( ExceptionMessage.NULL_URL_TO_FILE );
+
+      if( backendlessPath == null )
+        throw new NullPointerException( ExceptionMessage.NULL_PATH );
+
+      Invoker.invokeAsync( FILE_MANAGER_SERVER_ALIAS, "upload", new Object[] { urlToFile, backendlessPath, overwrite }, new AsyncCallback<String>()
+      {
+        @Override
+        public void handleResponse( String response )
+        {
+          responder.handleResponse( new BackendlessFile( response ) );
+        }
+
+        @Override
+        public void handleFault( BackendlessFault fault )
+        {
+          if( responder != null )
+            responder.handleFault( fault );
+        }
+      } );
+    }
+    catch( Throwable e )
+    {
+      if( responder != null )
+        responder.handleFault( new BackendlessFault( e ) );
+    }
+  }
+
   public BackendlessFile upload( File file, String path ) throws Exception
   {
     return upload( file, path, false );

src/com/backendless/exceptions/ExceptionMessage.java

@@ -52,6 +52,7 @@ public class ExceptionMessage
   public final static String NULL_EMPTY_TEMPLATE_NAME = "Template name can not be null or empty.";
   public final static String NULL_EMAIL_ENVELOPE = "EmailEnvelope can not be null.";
 
+  public final static String NULL_URL_TO_FILE = "URL to file cannot be null.";
   public final static String NULL_FILE = "File cannot be null.";
   public final static String NULL_PATH = "File path cannot be null or empty.";
   public final static String NULL_NAME = "File name cannot be null or empty.";