package org.kodejava.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;

import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet(urlPatterns = "/request-headers")
public class ServletRequestHeader extends HttpServlet implements Servlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter writer = response.getWriter();

        Enumeration<String> headerNames = request.getHeaderNames();
        while (headerNames.hasMoreElements()) {
            // Get request header name
            String name = headerNames.nextElement();

            // Get request header value
            String value = request.getHeader(name);
            writer.println("Header [" + name + "] = " + value + "<br/>");
        }

        writer.println("<br/>");

        headerNames = request.getHeaderNames();
        while (headerNames.hasMoreElements()) {
            String name = headerNames.nextElement();

            // Read request values, for header information that have multiple
            // values.
            Enumeration<String> values = request.getHeaders(name);
            while (values.hasMoreElements()) {
                String value = values.nextElement();
                writer.println("Header [" + name + "] = " + value + "<br/>");
            }
        }
        writer.close();
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // Do Nothing!
    }
}

Maven dependencies

<!--https://search.maven.org/remotecontent?filepath=javax/servlet/javax.servlet-api/4.0.1/javax.servlet-api-4.0.1.jar-->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
</dependency>

• Author
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Wayan

Founder at Kode Java Org

A programmer, runner, recreational diver, live in the island of Bali, Indonesia. Programming in Java, Spring, Hibernate / JPA. You can support me working on this project, buy me a cup of coffee ☕, every little bit helps, thank you 🙏

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