[FIXED] How to access .js file from within a servlet which is part of a web application plugin?

Issue

I can't find a way to access a javascript file which I put in the project folder of a plugin which I am trying to extend. The provided solution from this topic unfortunately didn't work. I hope this is not specific to the webapp (lets say its called thiswebappname) I am writing the plugin for. I started by extending on an existing example plugin, which has following project structure:

Project structure

myprojectsnamespace.myproject

• JRE System Library
• Plug-in Dependencies
• src
  • myprojectsnamespace.myproject
    • MyServlet.java
    • ...
• META-INF
• webapp
  • WEB-INF
    • javascript
      • myScript.js
  • web.xml
• build.properties
• plugin.xml

here some of the files which I suspect might be helpful for finding a solution:

build.properties

source.my-servlet.jar = src/
src.includes = my-servlet.jar
bin.includes = META-INF/,\
               webapp/,\
               plugin.xml

plugin.xml

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.0"?>
<plugin>
   <extension
         point="com.thiswebappname.portal.tomcat.webapps">
      <webapp
            contextRoot="webapp"
            name="thiswebappname/myprojectsnamespace"/>
   </extension>
</plugin>

I'm somehow not able to load the content of myScript.js from MyServlet. The servlet is kinda published by the web.xml:

<...>
<servlet>
  <servlet-name>MyServlet</servlet-name>
  <display-name>My Servlet</display-name>
  <servlet-class>myprojectnamespace.myproject.MyServlet</servlet-class>
</servlet>
<servlet-mapping>
  <servlet-name>MyServlet</servlet-name>
  <url-pattern>/LoadScript</url-pattern>
</servlet-mapping>

In MyServlet.java I tried the following, all without success:

MyServlet.java

public class MyServlet extends HttpServlet{
  private static final long serialVersionUID = 1L;
    
  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp ) throws IOException{
    resp.setContentType("text/html");
    resp.getWriter().println("<script>");
    resp.getWriter().println(new String(Files.readAllBytes(Paths.get("getPopup.js")),StandardCharsets.UTF_8));
    //above line doesn't find the file. I also tried "myprojectsnamespace.myproject/webapp/WEB-INF/javascript/myScript.js" etc., same problem
    resp.getWriter().println("</script>");

    /* following approach has the same problem, i.e. can't find the file:
    resp.setContentType("text/html");
    resp.getWriter().println("<script language='text/javascript' src='myScript.js'>");
    resp.getWriter().println("</script>"); */
}

When I enter http://myserver/thiswebappname/LoadScript in a browser, doGet() does get called from MyServlet as expected, but the script doesn't get loaded. Am I missing something obvious? I haven't found a way to "publish" the .js file like I did with MyServlet in the web.xml.

Solution

You could use:

ServletContext context = getContext();
URL resourceUrl = context.getResource("/WEB-INF/javascript/myScript.js");

or alternatively if you just want the input stream:

InputStream resourceContent = context.getResourceAsStream("/WEB-INF/javascript/myScript.js");

This works even if the Servlet Container never expands the WAR file (like Tomcat).

Answered By - Armando Ballaci