Magento – Magento Marketplace-Code Validation

I have submitted one module in Magento Marketplace. They gave me 2 errors in my code.

Use of echo language construct is discouraged.

Use of exit language construct is discouraged.

For echo, I have added /* @noEscape */ before echo.

But for exit, I don't know, how to solve error.

Code piece from Observer.php

           if ($maintenancePageBody != '') {
                if ($redirectPage == 0) {
                    /* @noEscape */ echo $blankpageMsg;
                } else if ($redirectPage == 1) {
                    /* @noEscape */ echo $maintenancePage;
                } else if ($redirectPage == 2 && $customUrl != '') {
                    header('Location:' . $customUrl);
                    exit;
                } else {
                    /* @noEscape */ echo $maintenancePage;
                }
            }
           // exit; /* my code */
           $this->getResponse()->setBody(); // I used this line instead of `exit`

Magento Marketplace error is,

Use of exit language construct is discouraged.

File: Model/Observer.php Line: 717 Column: 17 Source:
MEQP1.Security.LanguageConstruct.ExitUsage

EDIT

I submitted extension again.
echo error still occurs. $maintenancePage variable has HTML content.

Would anyone please help me, what should I do for echo and exit ?