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java – 将JSP标记转换为JSF组件

2019-07-01 07:50:37 作者：互联网

我有一个JSP标记,我想在我的JSF / Seam应用程序中使用.有人可以给我一些指导,让我的环境接受标签.我可以在我的旧标签上指定一个faclets * .taglib.xml文件,或者我是否需要编写一个扩展前一个标签的组件？

为任何信息干杯,
背风处

解决方法:

我非常不愿意尝试直接调用JSP上下文之外的JSP标记.作为documentation points out,JSP和Facelets之间的相似之处非常肤浅.

一个hack(我怀疑任何解决方案都将成为一个hack)可能是通过向下转换到servlet API来包含JSP.

此函数包含使用RequestDispatcher的给定资源：

public class Includer {

  public static String include(String resource) {
    FacesContext context = FacesContext
        .getCurrentInstance();
    ExternalContext ext = context.getExternalContext();
    include(ext.getContext(), ext.getRequest(), ext
        .getResponse(), resource);
    return "";
  }

  private static void include(Object context,
      Object request, Object response, String resource) {
    ServletContext servletContext = (ServletContext) context;
    ServletRequest servletRequest = (ServletRequest) request;
    ServletResponse servletResponse = (ServletResponse) response;
    RequestDispatcher dispatcher = servletContext
        .getRequestDispatcher(resource);
    try {
      dispatcher.include(servletRequest, servletResponse);
    } catch (IOException e) {
      throw new FacesException(e);
    } catch (ServletException e) {
      throw new FacesException(e);
    }
  }

}

此函数在Facelet taglib文件WEB-INF / facelets / include.taglib.xml中定义：

<?xml version="1.0" encoding="UTF-8"?>
<!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 xmlns="http://java.sun.com/JSF/Facelet">
  <namespace>http://demo</namespace>
  <function>
    <function-name>include</function-name>
    <function-class>inc.Includer</function-class>
    <function-signature>
      java.lang.String include(java.lang.String)
    </function-signature>
  </function>
</facelet-taglib>

这被指定为WEB-INF / web.xml using a context parameter中的库：

  <context-param>
    <param-name>facelets.LIBRARIES</param-name>
    <param-value>/WEB-INF/facelets/include.taglib.xml</param-value>
  </context-param>

用法示例

要包含的JSP,includeme.jsp：

<?xml version="1.0" encoding="UTF-8" ?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.0">
  <jsp:directive.page language="java"
    contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" />
  <b>Some data: ${foo}</b>
</jsp:root>

包含JSP的Facelet：

<!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:ui="http://java.sun.com/jsf/facelets"
  xmlns:h="http://java.sun.com/jsf/html"
  xmlns:demo="http://demo">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>JSP include hack</title>
</head>
<body>
<h:form>
  <p> ${demo:include('/includeme.jsp')} </p>
  <h:inputText type="text" value="#{foo}" />
  <h:commandButton type="submit" />
</h:form>
</body>
</html>

注意使用${demo：include(‘/ includeme.jsp’)}来调用请求调度程序(该函数返回一个空字符串).该函数包含在属性xmlns：demo =“http：// demo”中.请求范围变量foo绑定到文本字段并由JSP拾取.

我所能说的就是它对我有用,并且可能有十几个原因导致它不适用于某些标签组合或JSF库的某些组合.买者自负.

标签：java,jsf,taglib
来源： https://codeday.me/bug/20190701/1344836.html