Getting error "Cannot serialize because cannot determine how to serialize content-type application/x-www-form-urlencoded

When i try to upload the file using restapi I am getting below error . could you please help me how to fix the issue 

 given()  
         .header("Content-Type","application/x-www-form-urlencoded")
         .header("Accept","application/json")   
          .formParam("batchfile", new File("A.pdf"))
         .formParam("allowDuplicates","False").relaxedHTTPSValidation()
         .auth()
         .oauth2(acessToken)                                
         .post("url").then().log().all();