With tutorial we shall show you how to get all Init Parameters in Servlet. Using init parameters you can specify servelar inportant aspects of your servlets that are going to be handled during requests service.
In order to do that you should:
- Create
public void init()function on your servlet. - Call
getServletConfig().getInitParameterNames() - Use
put(initParamName, initParamValue)to put parameters in your init parameter map. - In your doGet method use
initParamsMap.entrySet().iterator()to get an Iterator an iterate through init parameters.
Let’s see the code snippets that follow:
package com.javacodegeeks.snippets.enterprise;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class GetAllInitParametersInServlet extends HttpServlet {
private static final long serialVersionUID = -2128122335811219481L;
private Map<String, String> initParamsMap = new HashMap<String, String>();
public void init() throws ServletException {
Enumeration<String> initParams = getServletConfig().getInitParameterNames();
System.out.println(initParams + " initParams");
while (initParams.hasMoreElements()) {
String initParamName = initParams.nextElement();
System.out.println(initParamName + " initParamName");
String initParamValue = getServletConfig().getInitParameter(initParamName);
initParamsMap.put(initParamName, initParamValue);
}
}
public void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException {
PrintWriter out = res.getWriter();
res.setContentType("text/plain");
Iterator<Map.Entry<String, String>> iter = initParamsMap.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry<String, String> entry = iter.next();
String key = entry.getKey();
String value = entry.getValue();
out.write(key);
out.write(" = ");
out.write(value);
out.write("n");
}
out.close();
}
}web.xml
<?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"> <display-name>JCG Snippets Web Project</display-name> <servlet> <servlet-name>JCG Snippets Application</servlet-name> <servlet-class>com.javacodegeeks.snippets.enterprise.GetAllInitParametersInServlet</servlet-class> <init-param> <param-name>myparam1</param-name> <param-value>myvalue1</param-value> </init-param> <init-param> <param-name>myparam2</param-name> <param-value>myvalue2</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>JCG Snippets Application</servlet-name> <url-pattern>/jcgservlet</url-pattern> </servlet-mapping> </web-app>
URL:
http://myhost:8080/jcgsnippets/jcgservletOutput:
myparam1 = myvalue1
myparam2 = myvalue2
This was an example on how to get all Init Parameters in Servlet.
