How can I get application parameters without going through the ServletContext object?
I have defined several application parameters for my webapp in the web.xml file like this:
<context-param>
<param-name>smtpHost</param-name>
<param-value>smtp.gmail.com</param-value>
</context-param>
If I have a ServletContext object, I can easily access them. For example, in my action classes Struts.
ServletContext ctx = this.getServlet().getServletContext();
String host = ctx.getInitParameter("smtpHost");
How to get application parameters without going through the ServletContext object?
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1 answer
Singleton + JNDI?
You can declare your object as a resource in your web application:
<resource-ref res-ref-name='myResource' class-name='com.my.Stuff'>
<init-param param1='value1'/>
<init-param param2='42'/>
</resource-ref>
Then, in your com.my.stuff class, you need a constructor and two "setters" for param1 and param2:
package com.my;
import javax.naming.*;
public class Stuff
{
private String p;
private int i;
Stuff(){}
public void setParam1(String t){ this.p = t ; }
public void setParam2(int x){ this.i = x; }
public String getParam1() { return this.p; }
public String getParam2(){ return this.i; }
public static Stuff getInstance()
{
try
{
Context env = new InitialContext()
.lookup("java:comp/env");
return (UserHome) env.lookup("myResource");
}
catch (NamingException ne)
{
// log error here
return null;
}
}
}
Then anywhere in your code:
...
com.my.Stuff.getInstance().getParam1();
Definitely redundant and inefficient, but it works (and can be optimized)
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