java - How can I get PNG Image from this code? Not able to view PNG Image in new Tab

Question

This is the groovy file for viewing the document. Please help me with this.

def viewDocument(byte [] documentContentByte, def contentType){
        log.debug("Entering viewDocument")
        response.setContentType(contentType)
        OutputStream out = response.getOutputStream()
        out.write(documentContentByte)
        out.flush()
        out.close()
        log.debug("Exiting viewDocument")
    }

This is the code where I am passing the byte [] to the method. I am able to view the PDF Format but Not able to view the PNG Image.

def viewShippingLabelAsPDF() {
        log.debug("Entering viewShippingLabelAsPDF");
        try {
            ViewDocumentResponse resp = session.getAttribute("viewLabelResp")
            
            if(resp!=null && resp.documentContentByte!=null && resp.documentContent!=null && resp.documentContent.substring(0, 20).contains("PDF")){
                
                log.info("In PDF");
                def contentType = "application/pdf" 
                byte[] contentByte = resp.getDocumentContentByte();
                
                viewDocument(contentByte, contentType);
            }

            else if(resp!=null && resp.documentContentByte!=null && resp.documentContent!=null && resp.documentContentDecoded!=null && resp.documentContentDecoded.substring(0, 10).contains("PNG")){
                
                log.info("In PNG");
                def contentType = "image/png";
                byte[] contentByte = resp.getDocumentContentByte();
                
                viewDocument(contentByte, contentType)
            }
            else {
                log.info("Not selected any in ViewLabel..Abhishek")
            }
        } catch (Exception e) {
            log.error("Exception in viewShippingLabelAsPDF::" +e)
        }
        log.debug("Exiting viewShippingLabelAsPDF");
    }
    ```
The output is Blank page with black color in background.

question from:https://stackoverflow.com/questions/65546432/how-can-i-get-png-image-from-this-code-not-able-to-view-png-image-in-new-tab

Answer 1

Waitting for answers