Solving issues of System.HttpResponse[Status=Method Not Allowed, StatusCode=405]

Question

I am trying to use REST in posting/inserting List of Account records from an origin org (OrgA) into a target org (OrgB). I have this error of "[45]|DEBUG|RESPONSE_BODY : System.HttpResponse[Status=Method Not Allowed, StatusCode=405]" which failing on the line where i do : HttpResponse res1 = http2.send(req1); How can I solve this issue? In my origin org I have the following code:

public class submitDataToTargetOrg {
    public static Map<String, String> oauthCustomSettings = Utils.getCustomSettingsKeyValueMapFull('Org_Credentials');
    public static List<String> oauthCustomSettingsValues = oauthCustomSettings.values();
    public static String clientId = oauthCustomSettingsValues.get(0).subStringBetween('|ClientId : |', '|ClientId|');
    public static String clientSecret = oauthCustomSettingsValues.get(0).subStringBetween('|ClientSec : |', '|ClientSec|');
    public static String userName= oauthCustomSettingsValues.get(0).subStringBetween('|UserName : |', '|UserName|');
    public static String password= oauthCustomSettingsValues.get(0).subStringBetween('|Password : |', '|Password|'); 
    public static void submitDataUsingGet(List<SObject> jsonToSubmit) {


    public static void submitDataUsingGet(List<SObject> jsonToSubmit) {

    List<Account> accList = (List<Account>)jsonToSubmit;
    String reqbody = 'grant_type=password&client_id='+clientId+'&client_secret='+clientSecret+'&username='+userName+'&password='+password;

    Http http = new Http();
    HttpRequest req = new HttpRequest();
    req.setBody(reqbody);
    req.setMethod('POST');
    req.setEndpoint('https://login.salesforce.com/services/oauth2/token');

    HttpResponse res = http.send(req);
    OAuth2 objAuthenticationInfo = (OAuth2)JSON.deserialize(res.getbody(), OAuth2.class);

    if(objAuthenticationInfo.access_token!=null){
        String requestBody = '{"req":{"accounts":'+JSON.serialize(accList)+'}}';
        String requestBody = JSON.serialize(postBody);
        Http http2 = new Http();
        HttpRequest req1 = new HttpRequest();
        string endP = 'https://eu6.salesforce.com/services/apexrest/getAccountData';//+jsonToSubmit;
        req1.setHeader('Authorization','Bearer '+objAuthenticationInfo.access_token);
        req1.setHeader('Content-Type','application/json');
        req1.setMethod('POST');
        req1.setBody(requestBody);
        req1.setEndpoint(endP);
        HttpResponse res1 = http2.send(req1);
        //List<Account> deserializedAccounts = (List<Account>)JSON.deserialize(jsonToSubmit, List<Account>.class);
        //if (deserializedAccounts.size() > 0) Database.delete([SELECT Id FROM Account WHERE Id IN: deserializedAccounts]);
    }
}

In the target org I have the following:

@RestResource(urlmapping = '/getAccountData/*')
    global  class accountRestService {

    PRIVATE STATIC FINAL BOOLEAN LOG_THIS_CLASS = TRUE;

    global class requestBody {
        global List<Account> accounts;
    }

    @httpPOST
    global static List<Account> populateAccountObject(accountRestService.requestBody req){
        //List<Account> deserializedAccounts = (List<Account>)JSON.deserialize(req.accounts, List<Account>.class);
        if (LOG_THIS_CLASS) System.debug('the request in populateAccountObject.. : ' + req);
        insert req.accounts;
        //String AccId = RestContext.request.params.get('AccountId');
        return req.accounts;
    }
}

Answer 1

May be because you are posting a POST request

i.e. req1.setMethod('POST');

And you have declared your service as PUT method

i.e. @httpPut

So you can try either by making

req1.setMethod('PUT');
or
@httpPost

Edit: Add the below changes as well to avoid getting 'Jason parse error'.

Update the JSON that you are sending in request body.

Remove These line;

Map<Id, Account> postBody = new Map<Id, Account>();
for(Account acc : (List<Account>)jsonToSubmit) postBody.put(acc.Id, acc);


String requestBody = JSON.serialize(postBody);

And add this instead;

List<Account> accList = (List<Account>)jsonToSubmit;
String requestBody = '{"req":{"accounts":'+JSON.serialize(accList)+'}}';

I referred this post.