How to Fetch Dynamically generated report from Server in android Using Retrofit?

Question

There are answers to this questions maybe but none of them helped me still getting the same error .

Actually trying to get dynamically generated report in android from server using retrofit .

But I am getting error while returning response . ERROR : onFailure:: Failed java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 1 path $

Please , I need help .

My Jason

{
"LoanDetails": [
                {
                "SrNo": "1",
                "LoanId": "BN582517",
                "StaffName": "Some Name",
                "Gender": "Male",
                "DisbursementDate": "2019-09-11",
                "RecoveryDate": "2019-10-11",
                "NameOfBorrower": "Muhammad Hassan Magsi",
                "GuardianName": "Allah Dino",
                "NICNumber": "Some CNIC",
                 "RegionName": "Some Name",
                "LoanAmountPrincipal": "100000",
                 "InterestRate": "22",
                 "LoanTerm": "12",
                     "TotalLoanAmount": "123000.0000",
                   "TotalRecoveredAmount": "0",
               "Balance": "Balance",
                  "LastPaymentDate": "--",
             "DueInstallment": "0",
              "OverDues": "0",
                "TotalDues": "0",
                  "PrePayment": "0",
                      "ReceiptNo": "3124",
                    "AmountRecovered": "",
               "RemainingDues": "",
                  "Date": "2019-09-11"
                }
          ]
       }

My Interface .

    public interface ApiInterface {

        @GET("employees/tabData/tablet_reports.php")
         Call < ServerResponseParser > getReport(); 
    }

Retrofit Client .

   public class ApiClient {
         public static final String BASE_URL = "http://mmsold.safcosupport.org/";
         public static Retrofit retrofit = null;
         public static final OkHttpClient okHttpClient = new OkHttpClient.Builder()
        .readTimeout(5, TimeUnit.MINUTES)
        .connectTimeout(5, TimeUnit.MINUTES)
        .build();

         public static Retrofit getClient() {

              if (retrofit == null) {
                     Gson gson = new GsonBuilder ()
                    .setLenient()
                    .create();
               retrofit = new Retrofit.Builder()
                             .baseUrl(BASE_URL)
                             .client(okHttpClient)
                             .addConverterFactory( GsonConverterFactory.create(gson))
                             .build();
            }
                return retrofit;
        }
   }

POJO Class .

   public class LoanDetail {
        @SerializedName("SrNo")
        @Expose
        private String srNo;
        @SerializedName("LoanId")
        @Expose
        private String loanId;
   }   

Just sample provide complete class if needed .

ServerResponseParser Class

public class ServerResponseParser implements Serializable {
      @SerializedName("LoanDetails")
      @Expose
      private ArrayList <LoanDetail> loanDetails = new ArrayList <LoanDetail>( );

      public ArrayList < LoanDetail > getLoanDetails () {
         return loanDetails;
      }

     public void setLoanDetails ( ArrayList < LoanDetail > loanDetails ) {
        this.loanDetails = loanDetails;
      }
 }

Code in MainActivity

public void getReport(){
    progressDialog = new ProgressDialog (MainActivity.this);
    progressDialog.setMessage("Fetching Data...");
    progressDialog.setCancelable(false);
    progressDialog.show();

    ApiInterface apiService =
            ApiClient.getClient().create(ApiInterface.class);
    Call<ServerResponseParser> call = apiService.getReport ();

    call.enqueue ( new Callback < ServerResponseParser > () {
        @Override
        public void onResponse ( Call < ServerResponseParser > call , Response < ServerResponseParser > response ) {
            if (response.isSuccessful ()){
                ArrayList<LoanDetail> statioList = response.body().getLoanDetails ();
                Log.e ( "onResponse: " , statioList.toString () + "" );
            }else {
                Log.e ( "onResponse: " , "Empty Response" + response.body ().toString () );
            }
            progressDialog.dismiss ();


        }

        @Override
        public void onFailure ( Call < ServerResponseParser > call , Throwable t ) {

            Log.e (  "onFailure: " , "Failed " + t.getMessage () );
            progressDialog.dismiss ();
        }
    } );


}