在Salesforce的visualforce页面中以pdf格式显示/下载web服务响应(blob

<apex:page controller="PDFController">
    <apex:form>
        <apex:commandButton value="Generate PDF" action="{!generatePDF}" rerender="pdfPanel"/>
        <apex:outputPanel id="pdfPanel">
            <apex:outputPanel rendered="{!showPDF}">
                <apex:iframe src="{!pdfURL}" width="100%" height="500px"/>
            </apex:outputPanel>
            <apex:outputPanel rendered="{!showDownloadLink}">
                <apex:commandLink value="Download PDF" action="{!downloadPDF}"/>
            </apex:outputPanel>
        </apex:outputPanel>
    </apex:form>
</apex:page>

public class PDFController {
    public Blob pdfBlob { get; set; }
    public Boolean showPDF { get; set; }
    public Boolean showDownloadLink { get; set; }
    public String pdfURL { get; set; }
    
    public void generatePDF() {
        // Call the web service and get the response as a blob
        // Replace the following code with your actual web service call
        // This is just a sample code to demonstrate the concept
        HttpRequest req = new HttpRequest();
        req.setEndpoint('https://example.com/webservice');
        req.setMethod('GET');
        HttpResponse res = new Http().send(req);
        pdfBlob = res.getBodyAsBlob();
        
        // Convert the blob to PDF format
        pdfBlob = pdfBlob.toPDF('Sample PDF');
        
        // Set the flags to show the PDF and download link
        showPDF = true;
        showDownloadLink = true;
        
        // Generate a unique URL for the PDF file
        pdfURL = '/servlet/servlet.FileDownload?file=' + EncodingUtil.urlEncode('Sample.pdf', 'UTF-8');
    }
    
    public PageReference downloadPDF() {
        // Set the response headers to download the PDF file
        PageReference pdfPage = new PageReference('/servlet/servlet.FileDownload?file=' + EncodingUtil.urlEncode('Sample.pdf', 'UTF-8'));
        pdfPage.getHeaders().put('Content-Disposition', 'attachment; filename=Sample.pdf');
        return pdfPage;
    }
}