src/main/java/com/squareup/connect/api/CustomersApi.java
public CompleteResponse<RetrieveCustomerResponse>retrieveCustomerWithHttpInfo(String customerId) throws ApiException {
    Object localVarPostBody = null;
    
    // verify the required parameter 'customerId' is set
    if (customerId == null) {
      throw new ApiException(400, "Missing the required parameter 'customerId' when calling retrieveCustomer");
    }
    
    // create path and map variables
    String localVarPath = "/v2/customers/{customer_id}"
      .replaceAll("\\{" + "customer_id" + "\\}", apiClient.escapeString(customerId.toString()));

    // query params
    List<Pair> localVarQueryParams = new ArrayList<Pair>();
    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
    localVarHeaderParams.put("Square-Version", "2019-11-20");

    
    
    final String[] localVarAccepts = {
      "application/json"
    };
    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);

    final String[] localVarContentTypes = {
      "application/json"
    };
    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);

    String[] localVarAuthNames = new String[] { "oauth2" };

    GenericType<RetrieveCustomerResponse> localVarReturnType = new GenericType<RetrieveCustomerResponse>() {};
    return (CompleteResponse<RetrieveCustomerResponse>)apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarPostBody, localVarHeaderParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
  }
/**
   * RetrieveCustomer
   * Returns details for a single customer.
   * @param customerId The ID of the customer to retrieve. (required)
   * @return CompleteResponse<RetrieveCustomerResponse>
   * @throws ApiException if fails to make API call
   */
RetrieveCustomer
Returns details for a single customer.
@param customerId The ID of the customer to retrieve. (required)
@return CompleteResponse
@throws ApiException if fails to make API call
RetrieveCustomer Returns details for a single customer . @param customerId The ID of the customer to retrieve . ( required ) @return CompleteResponse @throws ApiException if fails to make API call
public CompleteResponse<RetrieveCustomerResponse>retrieveCustomerWithHttpInfo(String customerId) throws ApiException {
    Object localVarPostBody = null;
    if (customerId == null) {
      throw new ApiException(400, "Missing the required parameter 'customerId' when calling retrieveCustomer");
    }
    String localVarPath = "/v2/customers/{customer_id}"
      .replaceAll("\\{" + "customer_id" + "\\}", apiClient.escapeString(customerId.toString()));
    List<Pair> localVarQueryParams = new ArrayList<Pair>();
    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
    localVarHeaderParams.put("Square-Version", "2019-11-20");
    final String[] localVarAccepts = {
      "application/json"
    };
    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
    final String[] localVarContentTypes = {
      "application/json"
    };
    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
    String[] localVarAuthNames = new String[] { "oauth2" };
    GenericType<RetrieveCustomerResponse> localVarReturnType = new GenericType<RetrieveCustomerResponse>() {};
    return (CompleteResponse<RetrieveCustomerResponse>)apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarPostBody, localVarHeaderParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
  }
public CompleteResponse < RetrieveCustomerResponse > retrieveCustomerWithHttpInfo ( String customerId ) throws ApiException { Object localVarPostBody = null ; if ( customerId == null ) { throw new ApiException ( 400 , "Missing the required parameter 'customerId' when calling retrieveCustomer" ) ; } String localVarPath = "/v2/customers/{customer_id}" . replaceAll ( "\\{" + "customer_id" + "\\}" , apiClient . escapeString ( customerId . toString ( ) ) ) ; List < Pair > localVarQueryParams = new ArrayList < Pair > ( ) ; Map < String , String > localVarHeaderParams = new HashMap < String , String > ( ) ; Map < String , Object > localVarFormParams = new HashMap < String , Object > ( ) ; localVarHeaderParams . put ( "Square-Version" , "2019-11-20" ) ; final String [ ] localVarAccepts = { "application/json" } ; final String localVarAccept = apiClient . selectHeaderAccept ( localVarAccepts ) ; final String [ ] localVarContentTypes = { "application/json" } ; final String localVarContentType = apiClient . selectHeaderContentType ( localVarContentTypes ) ; String [ ] localVarAuthNames = new String [ ] { "oauth2" } ; GenericType < RetrieveCustomerResponse > localVarReturnType = new GenericType < RetrieveCustomerResponse > ( ) { } ; return ( CompleteResponse < RetrieveCustomerResponse > ) apiClient . invokeAPI ( localVarPath , "GET" , localVarQueryParams , localVarPostBody , localVarHeaderParams , localVarFormParams , localVarAccept , localVarContentType , localVarAuthNames , localVarReturnType ) ; }
RetrieveCustomer
 Returns details for a single customer.
RetrieveCustomer Returns details for a single customer .
// verify the required parameter 'customerId' is set // create path and map variables // query params