Jsf文件下载不起作用 [英] Jsf file download doesn't work

问题描述

当我点击 h：commandButton 时，它会执行 myBean.dowanlod（）方法，但它没有' t下载任何文件。
这是我在backing bean中的方法。没有例外。光标变得忙碌，似乎在等待响应。是否有此类操作的其他配置或此代码是否有任何错误？

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;
  }

  //...
}

推荐答案

ICEfaces有一个奇怪的功能它隐式地将所有标准JSF < h：commandButton> 转换为启用ajax的命令按钮。但是，使用ajax下载文件是不可能的。您需要明确地将其关闭。您可以通过嵌套< f：ajax disabled =true> 来按每个按钮执行此操作。

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>

参见：

• p：fileDownload不使用h：head


• ICEfaces libary in classpath阻止另存为对话框弹出文件下载



See also:

• p:fileDownload not working with h:head
• ICEfaces libary in classpath prevents Save As dialog from popping up on file download

这篇关于Jsf文件下载不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！