当我尝试在代码中使用 primefaces 消息时遇到问题。当我刚刚进行测试时，消息运行良好，但是当我执行流文件并尝试在 xhtml 中发送消息时，该过程运行良好，但消息没有增长。
我的代码:
public void cadastrar () throws KeyStoreException, CADoesntExistsException, NoSuchAlgorithmException, CertificateException, IOException
{
FacesContext fc = FacesContext.getCurrentInstance();
if((controlador.checkUserIfExist(certificadoModel.getUsername()) == false) || (controlador.checkUserIfExist(certificadoModel.getUsername()) == true && authorization == true))
{
System.out.println("Revoke: " + authorization);
System.out.println("Check: " + controlador.checkUserIfExist(certificadoModel.getUsername()));
//KeyStore keyStore = controlador.cadastrar(certificadoModel);
System.out.println("Bean Class: " + certificadoModel.getMensagem());
/*
ExternalContext ec = fc.getExternalContext();
ec.responseReset();
ec.setResponseContentType("application/x-pkcs12");
//ec.setResponseContentLength(contentLength);
ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + certificadoModel.getUsername() + ".p12" + "\"");
OutputStream output = ec.getResponseOutputStream();
keyStore.store(output, certificadoModel.getPassword().toCharArray());
*/
fc.addMessage("mensagem", new FacesMessage(FacesMessage.SEVERITY_INFO, "Teste", ""));
//fc.responseComplete();
controlador.clean(certificadoModel);
}else
fc.addMessage("mensagem", new FacesMessage(FacesMessage.SEVERITY_ERROR, "Um usuário com o mesmo username já está cadastrado!", ""));
controlador.clean(certificadoModel);
}
我的页面代码:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui">
<ui:decorate template="/resources/template/default.xhtml">
<ui:define name="centro">
<h:form id="cadastro">
<p:panel id="painelCadastro" header="Novo Cadastro" style="margin-bottom:10px;">
<p:messages id="mensagem" autoUpdate="true" closable="true" />
<p:commandButton action="#{certificadoBean.cadastrar}" ajax="false" value="Cadastrar" update="mensagem" />
<p:commandButton outcome="homePage" ajax="false" value="Home Page"/>
</p:panel>
</h:form>
</ui:define>
</ui:decorate>
</html>
@BalusC，这就是我所做的。
xhtml
<p:commandButton value="Cadastrar" action="#{downloadBean.prepareDownload}" update="mensagem" />
<p:messages globalOnly="true" />
<h:outputScript rendered="#{not empty downloadBean.downloadKey}">
window.location = '#{request.contextPath}/download?key=#{downloadBean.downloadKey}';
</h:outputScript>
<p:commandButton outcome="homePage" ajax="false" value="Home Page"/>
</p:panel>
</h:form>
DownloadBean类
public class DownloadBean {
private String downloadKey;
public void prepareDownload() throws NamingException {
FacesContext context = FacesContext.getCurrentInstance();
CertificadoModel certificadoModel = new CertificadoModel();
CertificadoControlador controlador = new CertificadoControlador();
if ((controlador.checkUserIfExist(certificadoModel.getUsername()) == false))
{
downloadKey = UUID.randomUUID().toString();
context.getExternalContext().getSessionMap().put(downloadKey, certificadoModel);
context.addMessage("mensagem", new FacesMessage(FacesMessage.SEVERITY_INFO, "Usuário cadastrado com sucesso!", ""));
}else {
context.addMessage("mensagem", new FacesMessage(FacesMessage.SEVERITY_ERROR, "Um usuário com o mesmo username já está cadastrado!", ""));
}
}
public String getDownloadKey() {
return downloadKey;
}
下载Servlet类
public class DownloadServlet extends HttpServlet {
/****/
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) {
String downloadKey = request.getParameter("key");
CertificadoModel certificadoModel = (CertificadoModel) request.getSession().getAttribute(downloadKey);
System.out.println("Teste!");
CertificadoControlador controlador = null;
try {
controlador = new CertificadoControlador();
} catch (NamingException e) {
e.printStackTrace();
}
request.getSession().removeAttribute(downloadKey);
KeyStore keyStore = null;
try {
keyStore = controlador.cadastrar(certificadoModel);
} catch (KeyStoreException e) {
e.printStackTrace();
} catch (CADoesntExistsException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (CertificateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
response.reset();
response.setContentType("application/x-pkcs12");
//response.setContentLength(contentLength);
response.setHeader("Content-Disposition", "attachment; filename=\"" + certificadoModel.getUsername() + ".p12" + "\"");
try {
keyStore.store(response.getOutputStream(), certificadoModel.getPassword().toCharArray());
} catch (KeyStoreException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (CertificateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
在 web.xml 中
<servlet>
<servlet-name>DownloadServlet</servlet-name>
<servlet-class>br.com.certificado.beans.DownloadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>DownloadServlet</servlet-name>
<url-pattern>/download</url-pattern>
</servlet-mapping>
最佳答案
您基本上是在尝试向 1 个 HTTP 请求返回 2 个 HTTP 响应。这根本不可能。
最好的办法是有条件地在 URL 上渲染 JavaScript window.location 调用，该调用会发送一个新的 HTTP 请求，返回所需的文件下载。简单的 servlet 是完成这项工作的一个非常好的工具。您可以使用此答案中列出的方法之一访问 servlet 中的托管 bean:Get JSF managed bean by name in any Servlet related class或者您可以只生成一个唯一的 session 属性 key 并将其作为请求参数传递。
这是使用最后一种方法的启动示例:
<h:form>
...
<p:commandButton ... action="#{bean.prepareDownload}" update="@form" />
<p:messages globalOnly="true" />
<h:outputScript rendered="#{not empty bean.downloadKey}">
window.location = '#{request.contextPath}/download?key=#{bean.downloadKey}';
</h:outputScript>
</h:form>
(注意:/download 必须与 servlet 的 URL 模式完全匹配)
用这个bean:
private String downloadKey; // +Getter.
public void prepareDownload() {
FacesContext context = FacesContext.getCurrentInstance();
if (canDownload) {
downloadKey = UUID.randomUUID.toString();
context.getExternalContext().getSessionMap().put(downloadKey, certificadoModel);
context.addMessage(null, infoMessage);
} else {
context.addMessage(null, errorMessage);
}
}
以及这个 servlet:
@WebServlet("/download")
public class DownloadServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String downloadKey = request.getParameter("key");
CertificadoModel certificadoModel = (CertificadoModel) request.getSession().getAttribute(downloadKey);
request.getSession().removeAttribute(downloadKey);
// ...
response.reset();
response.setContentType("application/x-pkcs12");
response.setContentLength(contentLength);
response.setHeader("Content-Disposition", "attachment; filename=\"" + certificadoModel.getUsername() + ".p12" + "\"");
keyStore.store(response.getOutputStream(), certificadoModel.getPassword().toCharArray());
}
}
关于java - Primefaces 消息也不适用于流文件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15885497/