Styjun

I am having trouble with deserialising a jsonstring. In my debug I get the error System.JSONException: Unknown field: MyJSON.number. As number is a reserved field in salesforce I replace it with numberRep. I dont get why I get this error.

webservice

 @HttpPost
 global static void createOpportunity() 
 RestRequest req = RestContext.request; 
 string a = req.requestBody.toString().remove('\');
 system.debug('DEB1: '+ a); 
 MyJSON tClass = MyJSON.parse(a);
 system.debug('DEB2: '+ tClass);
 system.debug('DEB3: '+ tClass.billing.address_1 );
 system.debug('DEB4: '+ tClass.cart_hash);
 

Class

public class MyJSON
 public Integer id; //160
 public Integer parent_id; //0
 public String numberRep; //160
 public String order_key; //wc_order_mGsqFiG3RfTGz
 public String created_via; //admin
 public String version; //3.5.7
 public String status; //pending
 public String currencyRep; //EUR
 public String date_created; //2019-03-22T07:29:08
 public String date_created_gmt; //2019-03-22T07:29:08
 public String date_modified; //2019-03-22T07:29:14
 public String date_modified_gmt; //2019-03-22T07:29:14
 public String discount_total; //0.00
 public String discount_tax; //0.00
 public String shipping_total; //0.00
 public String shipping_tax; //0.00
 public String cart_tax; //0.00
 public String total; //0.00
 public String total_tax; //0.00
 public boolean prices_include_tax;
 public Integer customer_id; //0
 public String customer_ip_address; //
 public String customer_user_agent; //
 public String customer_note; //
 public cls_billing billing;
 public cls_shipping shipping;
 public String payment_method; //
 public String payment_method_title; //
 public String transaction_id; //
 public cls_date_paid date_paid;
 public cls_date_paid_gmt date_paid_gmt;
 public cls_date_completed date_completed;
 public cls_date_completed_gmt date_completed_gmt;
 public String cart_hash; //
 public cls_meta_data[] meta_data;
 public cls_line_items[] line_items;
 public cls_tax_lines[] tax_lines;
 public cls_shipping_lines[] shipping_lines;
 public cls_fee_lines[] fee_lines;
 public cls_coupon_lines[] coupon_lines;
 public cls_refunds[] refunds;
 public class cls_billing 
 public String first_name; //
 public String last_name; //
 public String company; //
 public String address_1; //
 public String address_2; //
 public String city; //
 public String state; //
 public String postcode; //
 public String country; //
 public String email; //
 public String phone; //
 
 public class cls_shipping 
 public String first_name; //
 public String last_name; //
 public String company; //
 public String address_1; //
 public String address_2; //
 public String city; //
 public String state; //
 public String postcode; //
 public String country; //
 
 public class cls_date_paid 
 
 public class cls_date_paid_gmt 
 
 public class cls_date_completed 
 
 public class cls_date_completed_gmt 
 
 public class cls_meta_data 
 
 public class cls_line_items 
 
 public class cls_tax_lines 
 
 public class cls_shipping_lines 
 
 public class cls_fee_lines 
 
 public class cls_coupon_lines 
 
 public class cls_refunds 
 
 public static MyJSON parse(String json)
 String jsonReplace = json.replace('"currency":', '"currencyRep":');
 jsonReplace = jsonReplace.replace('"number"','"numberRep"');
 return (MyJSON) System.JSON.deserializeStrict(json, MyJSON.class);
 

Jsonstring

"id":164,"parent_id":0,"number":"164","order_key":"wc_order_UeaNTHik3jec4","created_via":"admin","version":"3.5.7","status":"completed","currency":"EUR","date_created":"2019-03-22T08:37:18","date_created_gmt":"2019-03-22T08:37:18","date_modified":"2019-03-22T08:37:32","date_modified_gmt":"2019-03-22T08:37:32","discount_total":"0.00","discount_tax":"0.00","shipping_total":"0.00","shipping_tax":"0.00","cart_tax":"0.00","total":"0.00","total_tax":"0.00","prices_include_tax":false,"customer_id":0,"customer_ip_address":"","customer_user_agent":"","customer_note":"","billing":"first_name":"","last_name":"","company":"","address_1":"","address_2":"","city":"","state":"","postcode":"","country":"","email":"","phone":"","shipping":"first_name":"","last_name":"","company":"","address_1":"","address_2":"","city":"","state":"","postcode":"","country":"","payment_method":"","payment_method_title":"","transaction_id":"","date_paid":"2019-03-22","date_paid_gmt":"2019-03-22T08:37:32","date_completed":"2019-03-22T08:37:32","date_completed_gmt":"2019-03-22T08:37:32","cart_hash":"","meta_data":[],"line_items":[],"tax_lines":[],"shipping_lines":[],"fee_lines":[],"coupon_lines":[],"refunds":[]

Your class passes the wrong string to JSON.deserialize().

public static MyJSON parse(String json){
 String jsonReplace = json.replace('"currency":', '"currencyRep":');
 jsonReplace = jsonReplace.replace('"number"','"numberRep"');
 return (MyJSON) System.JSON.deserializeStrict(json, MyJSON.class);

You're transforming the string, but then not using the transformed version. Change the final line to

 return (MyJSON) System.JSON.deserializeStrict(jsonReplace, MyJSON.class);