如何在 Facelets 页面中包含 JSP 页面? [英] How to include a JSP page in a Facelets page?

问题描述

我在 Facelets 上使用 Myfaces 2.我必须在 Facelet 页面中包含一个 JSP 页面.我尝试使用 <ui:include> 但它只需要 XHTML 页面.我也尝试使用 <c:import> 和 <f:subview> 但没有任何效果.谷歌了很多，但没有得到确切的答案.

I am using Myfaces 2 on Facelets. I have to include a JSP page in a Facelet page. I tried using <ui:include> but it takes only XHTML pages. I also tried using <c:import> and <f:subview> but nothing worked. Googled a lot but didn't get the exact answer.

我怎样才能达到要求?

推荐答案

这可以通过自定义 UIComponent 实现.我的同事在一年前写了一篇关于这个的博客文章:Facelets and legacy JSP.

That's possible with a custom UIComponent. My fellow colleague has written a blog article about this a year ago: Facelets and legacy JSP.

是一些代码，但原理很简单，组件做了一个RequestDispatcher#include() 与自定义 HttpServletResponseWrapper 捕获写入的输出，然后将其写入JSF 组件.以下是相关性摘录:

It's some code, but the principle is easy, the component does a RequestDispatcher#include() with a custom HttpServletResponseWrapper which captures the written output and then writes it to the body of the JSF component. Here are extracts of relevance:

创建类com.example.component.JspIncludeComponent

public class JSPIncludeComponent extends UIComponentBase {

    public String getFamily() {
       return "components.jsp.include";
    }

    public void encodeBegin(FacesContext context) throws IOException {
       try {
          ExternalContext externalContext = context.getExternalContext();
          HttpServletRequest request = (HttpServletRequest) externalContext.getRequest();
          HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();

          // Create dispatcher for the resource given by the componen's page attribute.
          RequestDispatcher requestDispatcher = request.getRequestDispatcher((String) getAttributes().get("page"));

          // Catch the resource's output.
          CharResponseWrapper responseWrapper = new CharResponseWrapper(response);
          requestDispatcher.include(request, responseWrapper);

          // Write the output from the resource to the JSF response writer.
          context.getResponseWriter().write(responseWrapper.toString());
       }
       catch (ServletException e) {
          throw new IOException();
       }
    }

}

<小时>

创建类com.example.CharResponseWrapper

public class CharResponseWrapper extends HttpServletResponseWrapper {

   private CharArrayWriter output;

   @Override
   public String toString() {
      return output.toString();
   }

   public CharResponseWrapper(HttpServletResponse response) {
      super(response);
      output = new CharArrayWriter();
   }

   public CharArrayWriter getCharWriter() {
      return output;
   }

   @Override
   public PrintWriter getWriter() {
       return new PrintWriter(output);
  }

   @Override
   public ServletOutputStream getOutputStream() {
      return new CharOutputStream(output);
   }

   public InputStream getInputStream() {
      return new ByteArrayInputStream( toString().getBytes() );
   }
}

class CharOutputStream extends ServletOutputStream {

   private Writer output;

   public CharOutputStream( Writer writer ) {
      output = writer;
   }

   @Override
   public void write(int b) throws IOException {
      output.write(b);
   }
}

<小时>

在faces-config.xml中添加

<component>
    <component-type>com.example.component.JSPIncludeComponent</component-type>
    <component-class>com.example.component.JSPIncludeComponent</component-class>
</component>

<小时>

在WEB-INF文件夹中创建文件my.taglib.xml(Facelet taglib)

---

Create file my.taglib.xml (Facelet taglib) in the WEB-INF folder

<!DOCTYPE facelet-taglib PUBLIC "-//Sun Microsystems, Inc.//DTD Facelet Taglib 1.0//EN" "http://java.sun.com/dtd/facelet-taglib_1_0.dtd">

<facelet-taglib>
    <namespace>http://example.com/jsf</namespace> 

    <tag>
      <tag-name>include</tag-name>
      <component>
        <component-type>com.example.component.JSPIncludeComponent</component-type>
      </component>
    </tag>

</facelet-taglib>

<小时>

添加到 web.xml(如 http://docs.oracle.com/javaee/6/tutorial/doc/bnawn.html)

<context-param>
    <param-name>javax.faces.FACELETS_LIBRARIES</param-name>
    <param-value>/WEB-INF/my.taglib.xml</param-value>
</context-param>

<小时>

这样你就可以把它当做

---

This way you can use it as

<ui:component 
    xmlns:my="http://example.com/jsf"
    xmlns:ui="http://java.sun.com/jsf/facelets"
>
    <my:include page="page.jsp" />
</ui:composition>

<小时>

最后但同样重要的是，标记他的遗言

---

Last but not least, mark his last words

我不建议将其用作持久的解决方案，但它可能会简化从带有臭名昭著的 scriptlet 的旧 JSP 迁移到更健全和现代的 Facelets 应用程序.

这篇关于如何在 Facelets 页面中包含 JSP 页面?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！