Download file from url using Oracle ADF & Java- Download Manager

In this tutorial i will show you how to download a file from its url (web)-
as- http://www.tutorialspoint.com/java/java_tutorial.pdf
This will work as a simple download manager, you can add file url to download it and save it.
This tutorial makes use of FileHandling and java.net.URL class in java.

• User Interface is very simple to design as it have only one input text and one button, so create a fusion web application , and a bounded taskflow with a page fragment in it
• Now drag a Input text to enter url and a button to perform action on it from Componenet palette .
• Bind input text to bean to get its value from page



 private RichInputText fileUrlBind;

    public void setFileUrlBind(RichInputText fileUrlBind) {
        this.fileUrlBind = fileUrlBind;
    }

    public RichInputText getFileUrlBind() {
        return fileUrlBind;
    }

• Now create actionListener to managed bean and write code for downloading file from given url- see code



    public void DownloadFileButton(ActionEvent actionEvent) {
        try {
            if (fileUrlBind.getValue() != null) {
                String fileUrl = fileUrlBind.getValue().toString();
                if (fileUrl.startsWith("http://")) {
                    String msgNm = fileUrl.substring(7);

                    cnctmsgBind.setValue("Connecting to " + msgNm + "....");

                    URL url = new URL(fileUrl);
                    url.openConnection();
                    InputStream reader = url.openStream();


                    FileOutputStream writer =
                        new FileOutputStream("C:/javadrive." + fileUrl.substring(fileUrl.lastIndexOf(".")));
                    byte[] buffer = new byte[153600];
                    int totalBytesRead = 0;
                    int bytesRead = 0;

                   
                    dwnldMsgBind.setValue("Reading file 150KB blocks at a time");
                    while ((bytesRead = reader.read(buffer)) > 0) {
                        writer.write(buffer, 0, bytesRead);
                        buffer = new byte[153600];
                        totalBytesRead += bytesRead;
                    }
                 
                    alerMsgBind.setValue("File is downloaded successfully, look at your c drive :-)");
                    writer.close();
                    reader.close();
                } else {
                    FacesMessage errMsg = new FacesMessage("Something went wrong");
                    errMsg.setSeverity(FacesMessage.SEVERITY_ERROR);
                    errMsg.setDetail("Example- http://www.javadrive.co.in/java.pdf");
                    FacesContext context = FacesContext.getCurrentInstance();
                    context.addMessage(fileUrlBind.getClientId(), errMsg);
                }
            }
        } catch (MalformedURLException e) {
            FacesMessage errMsg = new FacesMessage("Something went wrong");
            errMsg.setSeverity(FacesMessage.SEVERITY_ERROR);
            FacesContext context = FacesContext.getCurrentInstance();
            context.addMessage(null, errMsg);
            e.printStackTrace();
        } catch (IOException e) {
            FacesMessage errMsg = new FacesMessage("Something went wrong");
            errMsg.setSeverity(FacesMessage.SEVERITY_ERROR);
            FacesContext context = FacesContext.getCurrentInstance();
            context.addMessage(null, errMsg);
            e.printStackTrace();
        }


    }






• Now Run your application and see downloaded file in your c drive as path is hard coded in bean

•  See your downloaded file in c drive

 

•  Download Sample Application- Happy Coding Sample ADF Application