JSF + JSON:输出“纯" servlet中的文本? [英] JSF + JSON: Output "plain" text in servlet?

问题描述

我正尝试将Mootools( Request.JSON )与JSF一起使用-主要是因为前段时间我在CakePHP中编写了类似的应用程序，并且希望重用大部分JS部分. /p>

有什么方法可以使用无标记的facelet之类的请求来返回纯文本("application/json")?

我想到的唯一解决方案是使用 HttpServlet 并将其注册到web.xml中的服务URL.这种方法有效并且确实返回了没有任何标记的文件，但是我宁愿使用我的Spring注入的ManagedProperties而不是仅限于WebApplicationContextUtils.

我错过了什么吗?还是推荐的方式?

解决方案

有一种方法.但这是对JSF/Facelets的丑陋且实质上是滥用，就像在使用错误的工具来完成工作一样.

例如

<ui:composition
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:ui="http://java.sun.com/jsf/facelets">
    <f:event type="preRenderView" listener="#{bean.renderJson}" />
</ui:composition>

使用

public void renderJson() throws IOException {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExternalContext externalContext = facesContext.getExternalContext();
    externalContext.setResponseContentType("application/json");
    externalContext.setResponseCharacterEncoding("UTF-8");
    externalContext.getResponseOutputWriter().write(someJsonString);
    facesContext.responseComplete();
}

更好的方法是使用JAX-RS Web服务.我不确定是否可以在其中注入Spring托管的bean，但是新的Java EE 6 CDI允许您通过@Inject在任何地方注入@Named bean，即使是在简单的@WebServlet中.

另请参见:

• Servlet与RESTful
• 如何使用Servlet和Ajax?

I'm trying to use Mootools (Request.JSON) together with JSF - mainly because I wrote a similar application in CakePHP some time ago and would like to reuse most of the JS part.

Is there any way to return plain text ("application/json") using an request from something like a markup-less facelet?

The only solution I came up with was using an HttpServlet and registering it to a service URL in web.xml. That approach works and really returns an file without any markup, but I'd rather use my Spring-injected ManagedProperties than being restricted to WebApplicationContextUtils.

Did I miss something or is that the recommended way?

解决方案

There is a way. But it's ugly and essentially abuse of JSF/Facelets as in using the wrong tool for the job.

E.g.

<ui:composition
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:ui="http://java.sun.com/jsf/facelets">
    <f:event type="preRenderView" listener="#{bean.renderJson}" />
</ui:composition>

with

public void renderJson() throws IOException {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExternalContext externalContext = facesContext.getExternalContext();
    externalContext.setResponseContentType("application/json");
    externalContext.setResponseCharacterEncoding("UTF-8");
    externalContext.getResponseOutputWriter().write(someJsonString);
    facesContext.responseComplete();
}

Much better is to use a JAX-RS web service. I'm not sure if Spring managed beans are injectable in there, but the new Java EE 6 CDI allows you to inject @Named beans everywhere by @Inject, even in a simple @WebServlet.

See also:

• Servlet vs RESTful
• How to use Servlets and Ajax?

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