programming-examples/java/Servlets_Session_Swing_Util/Servlet initialisation parameters.java
2019-11-15 12:59:38 +01:00

82 lines
2.5 KiB
Java

Servlet initialisation parameters
package com.ack.web.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* initialisation parameters inside the web.xml file
<servlet>
<servlet-name>initialisation</servlet-name>
<servlet-class>com.ack.web.servlet.ServletInitialisationParameters</servlet-class>
<init-param>
<param-name>jdbcurl</param-name>
<param-value>someurl</param-value>
</init-param>
<init-param>
<param-name>password</param-name>
<param-value>bah</param-value>
</init-param>
<init-param>
<param-name>username</param-name>
<param-value>foo</param-value>
</init-param>
</servlet>
*/
public class ServletInitialisationParameters extends HttpServlet {
public void init() throws ServletException {
String jdbcURL = getInitParameter( "jdbcurl" );
String username = getInitParameter( "username" );
String password = getInitParameter( "password" );
try {
if( jdbcURL == null || username == null || password == null ) {
StringBuffer buf = new StringBuffer( "you must specify the " );
buf.append( " 'jdbcurl', 'username', 'password' init params to -> " );
buf.append( getClass().getName() + " within you web.xml file" );
String msg = buf.toString();
System.out.println( buf );
// log( msg );
// throw new ServletException( msg );
}
else {
// possible get connection to database
}
}
catch( Exception ex ) {
log( ex.toString() );
throw new ServletException( ex.toString() );
}
finally {
// do any clean-up if you need to
}
log( "Completed Initialisation ->" + getClass().getName() );
}
public void doGet( HttpServletRequest req, HttpServletResponse res )
throws ServletException, IOException {
res.setContentType( "text/html" );
PrintWriter pw = res.getWriter();
pw.println( "<h3>Servlet Initialisation Parameters</h3>" );
pw.println( "<p><hr noshade><p>" );
Enumeration e = getInitParameterNames();
while( e.hasMoreElements() ) {
String paramName = (String) e.nextElement();
pw.println( "Initialisation Parameter: [ " );
pw.println( paramName + " = " + getInitParameter( paramName ) );
pw.println( " ]<br>" );
}
}
}