freemarker cannot handle request for '/' on google app engine

问题

I'm trying to get freemarker working under Google App Engine. I've gotten simple ftl template files working when requested directly however I'd like to have index.ftl work if available otherwise index.html -- or vice versa.

If I request /index.html, it renders fine as HTML.
If I request /index.ftl, it renders fine as a FreeMarker template. Variables are expanded.
If, however, I request '/' it gives the following 404 message:

Problem accessing /index.html/index.ftl.

I have the following in my web.xml file:

<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee"
     xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
        http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
        version="2.5">
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.ftl</welcome-file>
    </welcome-file-list>
    <servlet>
        <servlet-name>freemarker</servlet-name>
        <servlet-class>freemarker.ext.servlet.FreemarkerServlet</servlet-class>
        <init-param>
            <param-name>TemplatePath</param-name>
            <param-value>file://ftl</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>freemarker</servlet-name>
        <url-pattern>*.ftl</url-pattern>
    </servlet-mapping>
</web-app>

I have the following in the war/ directory of my Eclipse GAE application:

/index.html
/ftl/index.ftl
/WEB-INF/...

If I switch the order of the index.ftl and index.html entries, a request for / gives the following 404 message:

Problem accessing /index.ftl/index.ftl.

Thanks for any help.

One additional bit of information is that if I have one <welcome-file> entry of index.html, it works fine. When I add the index.ftl, in any order, is when I get the errors.

Thanks for any help.

回答1:

I think the problem here is pretty similar the problem of using a struts action as a welcome page. Quoting Damien B's answer from that question

There isn't ( a better way other than using a jsp redirect). Servlet specifications (Java Servlet Specification 2.4, "SRV.9.10 Welcome Files" for instance) state:

The purpose of this mechanism is to allow the deployer to specify an ordered list of partial URIs for the container to use for appending to URIs when there is a request for a URI that corresponds to a directory entry in the WAR not mapped to a Web component.

Since it is mapped to directory entry and not a mapped web component, the "/" isn't forwarding to the freemarker servlet when index.ftl is the welcome file.

I suggest trying the same approach used to make actions a welcome page. Which is have a jsp fwd to your index.ftl.

回答2:

I'm still looking for the solution to this (although @Andy Pryor's answer may be ultimately right) but I thought that I'd note what I've done to work around this issue.

I ended up moving all of my html files into the FreeMarker view hierarchy so that all HTML and FreeMarker files are processed by the FreeMarker servlet. I don't have to support *.ftl files since I will never be rendering them directly anyway. So the only files I have in my static hierarchy are images and the like.

This seems to be working well although I had to subclass the FreemarkerServlet to block the getSession() methods made on the request since my app does not have sessions enabled. Here's my web.xml file:

<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
        http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    version="2.5">

    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>
    <servlet>
        <servlet-name>freemarker</servlet-name>
        <servlet-class>freemarker.ext.servlet.FreemarkerServlet</servlet-class>
        <init-param>
            <param-name>TemplatePath</param-name>
            <param-value>file://views</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>freemarker</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>
</web-app>

来源：https://stackoverflow.com/questions/4127610/freemarker-cannot-handle-request-for-on-google-app-engine

标签

java

google-app-engine

freemarker

web.xml