I am reading 2 numbers as input and am trying to print them in the output dynamically using Servlet, req.getParameter() returns null:
HTTP Status 500 – Internal Server Error Type Exception Report
Message null
Description The server encountered an unexpected condition thatprevented it from fulfilling the request.
Exception
java.lang.NumberFormatException: null java.lang.Integer.parseInt(Integer.java:542)java.lang.Integer.parseInt(Integer.java:615)com.telusko.AddServlet.service(AddServlet.java:11)javax.servlet.http.HttpServlet.service(HttpServlet.java:741)org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)Note The full stack trace of the root cause is available in the serverlogs.
Apache Tomcat/9.0.26
Index.html
<!DOCTYPE html><html><head><meta charset="ISO-8859-1"><title>Insert title here</title></head><body><form action="add"> Enter 1st number: <input type="text' name="num1"><br> Enter 2nd number: <input type="text' name="num2"><br><input type="submit"></form></body></html>AddServlet.java
package com.telusko; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class AddServlet extends HttpServlet {public void service(HttpServletRequest req, HttpServletResponse res){ int i =Integer.parseInt(req.getParameter("num1")); int j =Integer.parseInt(req.getParameter("num2")); int k = i + j; System.out.println("result is"+k);} }Web.xml
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1"><servlet><servlet-name>abc</servlet-name><servlet-class>com.telusko.AddServlet</servlet-class></servlet><servlet-mapping><servlet-name>abc</servlet-name><url-pattern>/add</url-pattern></servlet-mapping>I know that my result will get printed in my eclipse console.