如何将javascript文件编译为jsp？

Question

I would like to be able to use the JSP servlet on my JavaScript files for i18n purposes. Take the following JavaScript for example:

function you_did_it_wrong() {
    alert("<fmt:message key="you.did.it.wrong" />");
}

I have tried to set up the JspServlet in my web.xml like this:

<servlet>
    <servlet-name>preprocessor</servlet-name>
    <servlet-class>org.apache.jasper.servlet.JspServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>preprocessor</servlet-name>
    <url-pattern>*.js</url-pattern>
</servlet-mapping>

But when I call the js file, it comes back without being processed by the servlet.

Answer 1

Bozho gave the right hint. However, I'd like to answer the concrete problem.

---

The given code snippet will fail when the fmt taglib is not declared in top of file:

<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<fmt:setLocale value="${language}" />
<fmt:setBundle basename="com.example.i18n.text" />

So just ensure that it is there above in your JS file.

The JSP servlet entry looks fine, although I think I would rather have used just this:

<servlet-mapping>
    <servlet-name>jsp</servlet-name>
    <url-pattern>*.js</url-pattern>
</servlet-mapping>

( jsp is the servlet-name of the Tomcat's builtin JspServlet which you can locate in its /conf/web.xml )

Answer 2

There are better ways to do that than serving .js files through the jsp servlet.

Check this question . I ended up having all variables declared in the .js file, and having them passed through an init method:

init({somgMsg: '<fmt:.../>', anotherMsg: '<fmt:... />'});