Jsf file download doesn't work

问题

When I click the h:commandButton it execute the myBean.dowanlod() method, but it doesn't download any files. Here is my methods in the backing bean. No exceptions. Cursor gets busy and seems like waiting for a response. Are there any additional configurations for this kind of operations or is there any wrong with this code?

<h:commandButton value="download" action="#{myBean.download()}" /> 

@ManagedBean
@SessionScoped    
public class MyBean implements Serializable{
   //....

   public String download{

    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExternalContext externalContext = facesContext.getExternalContext();

    String fileName = "test.txt";
    String filePath = "D:\\test.txt"; //externalContext.getRealPath("") + File.separator + fileName;
    File file = new File(filePath);

    externalContext.setResponseHeader("Content-Type", "text/plain");
    externalContext.setResponseHeader("Content-Length", String.valueOf(file.length()));
    externalContext.setResponseHeader("Content-Disposition", "attachment;filename=\"" + fileName + "\"");


    InputStream input = null;
    OutputStream output = null;

    try {
        input = new FileInputStream(file);
        output = externalContext.getResponseOutputStream();
        IOUtils.copy(input, output);
    } catch (FileNotFoundException ex) {
        ex.printStackTrace();
    } catch (IOException ex) {
        ex.printStackTrace();
    } finally {
        IOUtils.closeQuietly(output);
        IOUtils.closeQuietly(input);
    }

    facesContext.responseComplete();
    return null;
  }

  //...
}

回答1:

ICEfaces has the strange "feature" that it implicitly converts all standard JSF <h:commandButton> to ajax-enabled command buttons. However, it's not possible to download files using ajax. You need to explicitly turn it off. You can do that on a per-button basis by nesting a <f:ajax disabled="true">.

<h:commandButton value="download" action="#{myBean.download()}" />
    <f:ajax disabled="true"/>
</h:commandButton>

回答2:

Previously I had <h:head> and <ice:form>. This file download thing doesn't work with those namespaces. Just using <head> and <h:form> resolve the problem. I'm learning JSF, so I have no idea about this. Somehow it works for me. And I found much better file download tutorial from BalusC's blog. If anyone knows or can guess the reason please give some ideas.

来源：https://stackoverflow.com/questions/15131582/jsf-file-download-doesnt-work

标签

jsf

java-ee

jsf-2

icefaces

Jsf file download doesn't work

问题

回答1:

See also:

回答2: