--- title: "Session 2" description: "JSP" image: "https://syntax.theether.in/og.png" --- > Documentation Index > Fetch the complete documentation index at: https://syntax.theether.in/llms.txt > Use this file to discover all available pages before exploring further. # Session 2 JavaServer Pages put Java inside HTML so that the view is easier to write than a servlet full of `println` calls. The session covers scripting elements, JSTL, JDBC from a page, action elements, implicit objects and a small combined project. ## Objectives - Complete questions 6 to 12 of the manual: jsp - Prepare the deliverable before the lab and finish it during the session - Be ready to explain every step in the viva ## Questions Covered | Question | Requirement | Status | | --- | --- | --- | | Q6 | Write JSP Programme to print current date and time along with timestamp, implement... | Complete | | Q7 | Create a JSP page and implement a Scripting Tag, Expression tag and Declaration tag | Complete | | Q8 | Import JSTL library in JSP Page and use its following tags | Complete | | Q9 | Create a JSP Page for database connectivity using JDBC and show the students details... | Complete | | Q10 | Write a JSP application using following Action Elements | Complete | | Q11 | Write a JSP program using the following implicit objects with an example | Complete | | Q12 | Create a JSP Project implementing all the above (Session 1 and Session 2) concepts.... | Complete | ## Preparation - Add the JSTL jars (jakarta.servlet.jsp.jstl and its API) to the project; JSTL is not part of Tomcat. - For auto-refresh use `response.setHeader("Refresh", "5")` or a meta refresh tag. - Question 12 is a mini project: plan its pages (login, list, add, edit, delete, error) before coding. - One Maven web project `JspLab` holds all seven answers, with the same `pom.xml` as Session 1. JSP pages go in `src/main/webapp/`, Java classes in `src/main/java/ignou/`. Questions 9 and 12 need the IGNOU database from Session 1, Question 5. ## Project Setup 1. Create the project as in Session 1 (NetBeans: File, New Project, Java with Maven, Web Application, name, Next, server Tomcat 10.1, Finish; Eclipse: Dynamic Web Project, then Convert to Maven Project) and name it `JspLab`. Copy the Session 1 `pom.xml`, changing `artifactId` and `finalName`. 2. To add a page: right-click Web Pages (NetBeans) or `src/main/webapp` (Eclipse), New, JSP, name without extension. Base URL after Run: `http://localhost:8080/JspLab/`. ## Question 6 ### Problem Statement Write JSP Programme to print current date and time along with timestamp, implement auto-refresh of a page. ### Solution #### Steps 1. New JSP `datetime` in `src/main/webapp/`; paste the listing. 2. Run and open `http://localhost:8080/JspLab/datetime.jsp`. Leave it for 20 seconds: the seconds and the timestamp advance on their own every 5 seconds. 3. In the browser dev tools, Network tab, watch a new request appear every 5 seconds. #### Program ```html title="datetime.jsp" file=/public/code/mcsl-222/section-2/session-2/datetime.jsp ``` #### Output Checked by reading, not executed (no Tomcat here). The page repaints itself every five seconds; one snapshot: ```text Current Date and Time Date: 26-09-2026 Time: 11:02:15 Full: Sat Sep 26 11:02:15 IST 2026 Timestamp (ms since epoch): 1790398335518 SQL Timestamp: 2026-09-26 11:02:15.518 This page refreshes every 5 seconds. Watch the seconds change. ``` #### Explanation - Tomcat compiles the JSP into a servlet on first request (`work/Catalina/localhost/JspLab/org/apache/jsp/datetime_jsp.java`); HTML becomes `out.write` calls, scriptlet code is copied into `_jspService`. - `response.setHeader("Refresh", "5")` asks the browser to re-request the URL after 5 seconds; the `meta http-equiv="refresh"` tag does the same from the HTML side. One is enough; both are shown so you can explain either in the viva. Headers must be set before output is committed, so the scriptlet sits above the DOCTYPE. - `System.currentTimeMillis()` is the timestamp; `SimpleDateFormat` turns it into date and time strings. ## Question 7 ### Problem Statement Create a JSP page and implement a Scripting Tag, Expression tag and Declaration tag. ### Solution #### Steps 1. New JSP `scripting` in `src/main/webapp/`. 2. Open `http://localhost:8080/JspLab/scripting.jsp`, reload several times, then open `scripting.jsp?name=Asha`. #### Program ```html title="scripting.jsp" file=/public/code/mcsl-222/section-2/session-2/scripting.jsp ``` #### Output Checked by reading. Third visit with `?name=Asha`: ```text JSP Scripting Elements Hello, Asha! You are visitor number 3. Factorial of 5 is 120. Multiplication table of 7 (scriptlet loop) 7 x 1 = 7 ... 7 x 10 = 70 (ten rows) Your name: [Asha] [Greet] ``` #### Explanation | Element | Syntax | Becomes in the generated servlet | Used here for | | --- | --- | --- | --- | | Declaration | `<%! ... %>` | Class-level field or method, outside `_jspService` | `hitCount` field, `factorial()` method | | Scriptlet | `<% ... %>` | Statements inside `_jspService`, run on every request | Reading `name`, incrementing `hitCount`, the `for` loop | | Expression | `<%= ... %>` | `out.print(...)` of the value | Printing `name`, `hitCount`, `factorial(n)`, `7 * i` | - `hitCount` keeps counting across requests because it is a field of the one servlet instance; it resets when the page is recompiled or the application redeploys. It is also shared by all users and not thread-safe, which is why real applications keep such state in a session or a database. - An expression must not end with a semicolon; a scriptlet must. - The loop opens in one scriptlet and closes in another; the HTML row between them is emitted on every iteration. ## Question 8 ### Problem Statement Import JSTL library in JSP Page and use its following tags: 1. out 2. if 3. forEach 4. choice, when and otherwise 5. url and redirect ### Solution #### Steps 1. Confirm the two JSTL artifacts (`jakarta.servlet.jsp.jstl-api` 3.0.0 and Glassfish `jakarta.servlet.jsp.jstl` 3.0.1) are in `pom.xml`; without Maven, download both jars and drop them into `src/main/webapp/WEB-INF/lib/`. 2. New JSP `jstl-demo`; keep `datetime.jsp` from Question 6 as the redirect target. 3. Open `http://localhost:8080/JspLab/jstl-demo.jsp`, then click the two links at the bottom. #### Program ```html title="jstl-demo.jsp" file=/public/code/mcsl-222/section-2/session-2/jstl-demo.jsp ``` #### Output Checked by reading. First visit without parameters: ```text JSTL Core Tag Demo 1. c:out Student: Asha Verma Unknown parameter with default: not given Escaped: bold? 2. c:if Add ?name=YourName to the URL to see c:if fire. 3. c:forEach # Marks Result 1 78 Distinction 2 92 Distinction 3 45 Fail 4 66 Pass 5 88 Distinction (five rows) Counting with begin/end/step: 1 4 7 10 5. c:url and c:redirect Reload with name and city (built by c:url) Rendered link: /JspLab/jstl-demo.jsp?name=Rahul+Singh&city=Kolkata Go to the clock page (c:redirect) ``` Clicking the first link shows `Hello, Rahul Singh` under c:if and `Kolkata` under c:out. Clicking the second sends the browser to `/JspLab/datetime.jsp` with an HTTP 302 and the address bar changes. #### Explanation - The taglib directive `uri="jakarta.tags.core"` is the JSTL 3.0 name; the old `java.sun.com` URI belongs to JSTL 1.2 on `javax` and fails on Tomcat 10.1 with "cannot be resolved". - `c:out` prints an EL value and escapes XML characters by default, so `` shows literally; `default` covers missing values. `c:if` has no else; for branches use `c:choose` with `c:when` and one `c:otherwise` (the manual's "choice"). - `c:forEach` walks any collection or array (`items`) or counts (`begin`, `end`, `step`). `varStatus` gives `index`, `count`, `first`, `last`. - `c:url` prepends the context path, URL-encodes nested `c:param` values and appends `;jsessionid` when cookies are off. `c:redirect` sends a 302 and stops the page; it must run before any output, which is why it sits at the top. ## Question 9 ### Problem Statement Create a JSP Page for database connectivity using JDBC and show the students details from the database created during exercise no 5 in session 1. ### Solution #### Steps 1. MySQL must be running with the IGNOU database from Session 1 (`schema.sql`). 2. `mysql-connector-j` is already in `pom.xml`; if not using Maven, copy the jar to `WEB-INF/lib/`. 3. New JSP `student-list`; open `http://localhost:8080/JspLab/student-list.jsp`. Stop MySQL and reload once to see the error branch. #### Program ```html title="student-list.jsp" file=/public/code/mcsl-222/section-2/session-2/student-list.jsp ``` #### Output Checked by reading. With the three seeded rows: ```text Students in IGNOU database Enrolment Name DOB Email Mobile Programme Semester Courses 2451001234 Asha Verma 2001-03-14 asha.verma@example.com 9876543210 MCA 2 MCS-218,MCS-219,MCS-220,MCS-221 2451001235 Rahul Singh 2000-11-02 rahul.singh@example.com 9123456780 MCA 2 MCS-218,MCS-220,MCS-221 2451001236 Meera Nair 2002-07-25 meera.nair@example.com 9988776655 MCA 1 MCS-211,MCS-212,MCS-213 Total students: 3 ``` With MySQL stopped: `Database error: Communications link failure` in red, followed by the hint line. #### Explanation - The JDBC steps are the same as in the DAO of Session 1: `DriverManager.getConnection(url, user, password)`, `prepareStatement`, `executeQuery`, loop over `ResultSet`. Connector/J 8 registers its driver automatically through the service loader, so `Class.forName("com.mysql.cj.jdbc.Driver")` is optional. - The `try` with resources declares the connection, statement and result set together; they close in reverse order whether the loop finishes or throws. - The scriptlet is split around the HTML so the header is written once and a row per `rs.next()`. SQL inside a JSP is acceptable here but mixes data access with presentation; Question 12 moves it back into `StudentDao`. ## Question 10 ### Problem Statement Write a JSP application using following Action Elements 1. jsp:forward 2. jsp:include 3. set and getProperty 4. jsp:useBean ### Solution #### Steps 1. Add class `StudentBean` in package `ignou` (Source Packages, New, Java Class). 2. Add three JSPs in `src/main/webapp/`: `header`, `action-demo`, `bean-view`. 3. Open `http://localhost:8080/JspLab/action-demo.jsp`. Submit with a name: `bean-view.jsp` shows the bean. Submit with the name empty: you are forwarded back to the form with a red message while the address bar still says `bean-view.jsp`. #### Program ### StudentBean.java ```java title="StudentBean.java" file=/public/code/mcsl-222/section-2/session-2/StudentBean.java ``` ### header.jsp ```html title="header.jsp" file=/public/code/mcsl-222/section-2/session-2/header.jsp ``` ### action-demo.jsp ```html title="action-demo.jsp" file=/public/code/mcsl-222/section-2/session-2/action-demo.jsp ``` ### bean-view.jsp ```html title="bean-view.jsp" file=/public/code/mcsl-222/section-2/session-2/bean-view.jsp ``` #### Output Checked by reading. Submitting name `Meera Nair`, programme `MCA`, semester `2`: ```text IGNOU Web Technologies Lab | Page title: Bean View | Served at Sat Sep 26 11:20:44 IST 2026 Values read back with jsp:getProperty Name Meera Nair Programme MCA Semester 2 After setProperty with a literal value, programme = MCA (forced) Back ``` Submitting with an empty name leaves the address bar at `/JspLab/bean-view.jsp` but renders the form page with the header titled `Action Elements` and the red line `Name is required (you were forwarded back by jsp:forward)`. #### Explanation | Action | What it does | Where in the code | | --- | --- | --- | | `jsp:include` | Runs another resource at request time and inserts its output; `jsp:param` adds request parameters visible only inside it | `header.jsp` at the top of both pages, with `title` | | `jsp:forward` | Hands the same request to another page and discards any output so far; the browser URL does not change | Empty name in `bean-view.jsp` | | `jsp:useBean` | Looks for a bean with that `id` in the given scope, creates one with the no-arg constructor if absent | `student` in request scope | | `jsp:setProperty` | Calls setters; `property="*"` matches every request parameter to a same-named setter and converts types | Fills name, programme, semester (String to int) | | `jsp:getProperty` | Calls the getter and prints the value | The three table rows | - `jsp:include` differs from the `include` directive: the directive pastes source at translation time, the action calls the page at request time, so the header's date is always current. The forward happens before any output; forwarding after content was flushed throws `IllegalStateException`. ## Question 11 ### Problem Statement Write a JSP program using the following implicit objects with an example: 1. out 2. request 3. response 4. session 5. pageContext 6. exception ### Solution #### Steps 1. Add JSPs `implicit` and `error` in `src/main/webapp/`. 2. Open `http://localhost:8080/JspLab/implicit.jsp?name=Asha`, reload twice, then click the divide-by-zero link. In dev tools, Network, the response headers show `X-Lab: MCSL-222` and `Set-Cookie: lastPage=implicit`. #### Program ### implicit.jsp ```html title="implicit.jsp" file=/public/code/mcsl-222/section-2/session-2/implicit.jsp ``` ### error.jsp ```html title="error.jsp" file=/public/code/mcsl-222/section-2/session-2/error.jsp ``` #### Output Checked by reading. Second visit: ```text JSP Implicit Objects 1. out Written with out.println(). Buffer size: 8192 bytes, remaining: 7810 2. request Method: GET, URI: /JspLab/implicit.jsp, client IP: 0:0:0:0:0:0:0:1, name parameter: Asha 3. response Content type set to text/html;charset=UTF-8; header X-Lab and cookie lastPage added (see browser dev tools). 4. session Session id: 7D2C9F1A4B8E3C6D0A5F2E9B1C4D7A8E, visits: 2, new: false 5. pageContext page scope: only visible on this page application scope via pageContext: visible to every page session via pageContext: true (same object as session) 6. exception Click to divide by zero; error.jsp shows the exception object. ``` After clicking the link (`implicit.jsp?fail=1`) the browser shows `error.jsp`: `Exception type: java.lang.ArithmeticException`, `Message: / by zero`, `Thrown from: org.apache.jsp.implicit_jsp._jspService(implicit_jsp.java:142)`. #### Explanation | Object | Type | Example use in the page | | --- | --- | --- | | `out` | `JspWriter` | `out.println`, buffer size and remaining space | | `request` | `HttpServletRequest` | method, URI, remote address, `name` parameter | | `response` | `HttpServletResponse` | `setHeader`, `addCookie`, content type | | `session` | `HttpSession` | id, visit counter attribute, `isNew()` | | `pageContext` | `PageContext` | attributes in page and application scope, `findAttribute`, `getSession()` | | `exception` | `Throwable` | class name, message, first stack frame in `error.jsp` | - The six objects are local variables that Tomcat declares at the top of `_jspService`; that is why they exist without any import. - `exception` exists only in a page marked `isErrorPage="true"`. The page that can fail names its handler with `errorPage="error.jsp"`; on an uncaught exception Tomcat forwards to it and sets the `exception` object. `error.jsp` also serves the `web.xml` error pages of Question 12, where it reads the status code from the `jakarta.servlet.error.status_code` attribute. - `pageContext.findAttribute` searches page, request, session then application scope in that order; it is what EL uses when it resolves a bare name. ## Question 12 ### Problem Statement Create a JSP Project implementing all the above (Session 1 and Session 2) concepts. Login Form, CRUD operation of Student details, Session Management with exception handling using Servlet and JSP. Make necessary assumptions required. ### Solution #### Assumptions - Single administrator account `admin` / `ignou123` hard-coded in `LoginServlet`; a Users table with hashed passwords is left for Session 9 (Spring Security). Database, `Student` and `StudentDao` are those of Session 1, Question 5. - Session timeout is 10 minutes; after that any request to `/students` returns to the login page with a message. - All database and conversion errors surface either as a red message on the list page (expected errors such as a duplicate enrolment number) or on `error.jsp` (anything unexpected, through `web.xml`). #### Steps 1. In `JspLab` copy `Student.java` and `StudentDao.java` from Session 1 into package `ignou`. 2. Add `LoginServlet`, `LogoutServlet`, `StudentController` to package `ignou`. 3. Add `login.jsp` in `src/main/webapp/` (Question 11's `error.jsp` is reused as is). Create folder `src/main/webapp/WEB-INF/views/` and add `students.jsp` and `student-form.jsp` there. 4. Replace `WEB-INF/web.xml` with the listing below. 5. Run. `http://localhost:8080/JspLab/` opens `login.jsp`. Try a wrong password, then the correct one. Add, edit and delete a student as in Session 1. 6. Click Logout, then type `http://localhost:8080/JspLab/students` directly: you land on the login page with "Please login first". Open `/JspLab/nothing.jsp` for the 404 branch of `error.jsp`; stop MySQL and open the list for the exception branch. #### Program ### web.xml ```xml title="web.xml" file=/public/code/mcsl-222/section-2/session-2/web.xml ``` ### login.jsp ```html title="login.jsp" file=/public/code/mcsl-222/section-2/session-2/login.jsp ``` ### LoginServlet.java ```java title="LoginServlet.java" file=/public/code/mcsl-222/section-2/session-2/LoginServlet.java ``` ### LogoutServlet.java ```java title="LogoutServlet.java" file=/public/code/mcsl-222/section-2/session-2/LogoutServlet.java ``` ### StudentController.java ```java title="StudentController.java" file=/public/code/mcsl-222/section-2/session-2/StudentController.java ``` ### students.jsp ```html title="students.jsp" file=/public/code/mcsl-222/section-2/session-2/students.jsp ``` ### student-form.jsp ```html title="student-form.jsp" file=/public/code/mcsl-222/section-2/session-2/student-form.jsp ``` `Student.java` and `StudentDao.java` are the Session 1, Question 5 listings, copied without change. #### Output Checked by reading, not executed. A wrong password returns to `login.jsp` with `Invalid username or password` in red above the form. After a correct login the browser is at `/JspLab/students` and shows `Logged in as admin | Logout`, the heading `IGNOU Students (3)`, the `Add new student` link and the same three-row table as Session 1, Question 5, each row ending in Edit and a Delete button. After Save on the edit form the same list reappears with `Student updated` in green. Visiting `/students` after Logout shows the login page with `Please login first`. With MySQL stopped, `error.jsp` shows `Exception type: jakarta.servlet.ServletException`, `Message: Database error: Communications link failure`. A wrong URL shows `HTTP status 404 for /JspLab/nothing.jsp`. #### Explanation - Flow: `login.jsp` (view) posts to `LoginServlet` (controller), which stores `user` in the `HttpSession` and redirects to `StudentController`. The controller loads data through `StudentDao` (model), puts it in request attributes and forwards to a JSP under `WEB-INF/views/`. That is Model-View-Controller with plain servlets and JSP, the shape Spring MVC automates in Sessions 3 to 5. - Session management: `loggedIn()` runs before every action and checks `session.getAttribute("user")`. Login invalidates any old session first so an attacker cannot plant a known session id (fixation). `web.xml` sets a 10 minute timeout and `http-only` on the cookie; `LogoutServlet` invalidates and redirects. - Views under `WEB-INF` cannot be requested by URL, so nobody can open `students.jsp` without going through the controller and its login check. - Exception handling has two levels. Expected failures (duplicate key, bad number) are caught in `doPost` and shown as a message. Anything else is wrapped in `ServletException` and left to the container, which the `error-page` entries route to `error.jsp`; the same page handles 404. - The views use JSTL and EL only (`c:forEach`, `c:out`, `c:url`, `c:if`, `fn:contains`), no scriptlets; every POST ends in a redirect to `/students` (Post-Redirect-Get). ## Viva Questions - **Q:** How is a JSP different from a servlet? **A:** A JSP is translated into a servlet by the container; it is HTML with embedded Java rather than Java with embedded HTML, so it suits the view layer. - **Q:** What is the JSP life cycle? **A:** Translation to a `.java` file, compilation, class loading, `jspInit()`, `_jspService()` per request, `jspDestroy()`. - **Q:** Difference between the include directive and `jsp:include`? **A:** The directive merges source at translation time; the action calls the resource at request time and can pass parameters. - **Q:** Why prefer JSTL and EL over scriptlets? **A:** Views stay readable, output is escaped by default, no Java in HTML, and designers can edit the page. - **Q:** How does `errorPage` differ from the `error-page` in `web.xml`? **A:** `errorPage` is per JSP; `web.xml` mappings apply to the whole application and also cover servlets and HTTP status codes. - **Q:** Why put JSPs under `WEB-INF`? **A:** The container never serves `WEB-INF` directly, so the pages can only be reached by a forward from a servlet that has done its checks. - **Q:** What is the JSTL core URI for Tomcat 10.1? **A:** `jakarta.tags.core` (JSTL 3.0); the old `java.sun.com` URI is for the `javax` versions. ## Common Mistakes - Using the JSTL 1.2 URI or jar on Tomcat 10.1: "The absolute uri cannot be resolved" at translation time. - Setting a header or calling `c:redirect` after HTML has been written: `IllegalStateException: response already committed`. - A bean without a public no-arg constructor or with a getter that does not match the property name: `jsp:useBean` or `getProperty` fails at run time. - Forgetting `isErrorPage="true"`: the `exception` object is undefined and the error page itself fails to compile. - Leaving `students.jsp` outside `WEB-INF`, which lets anyone skip the login check by typing its URL. ## Session Summary - Project `JspLab` on Tomcat 10.1 with JSTL 3.0 (`jakarta.tags.core`) and `mysql-connector-j` - Question 6: `datetime.jsp` with date, time, timestamp and 5 second auto-refresh (Refresh header and meta tag) - Question 7: `scripting.jsp` with declaration, scriptlet and expression elements - Question 8: `jstl-demo.jsp` using `c:out`, `c:if`, `c:forEach`, `c:choose`/`c:when`/`c:otherwise`, `c:url`, `c:redirect` - Question 9: `student-list.jsp` reading the IGNOU Student table through JDBC - Question 10: `StudentBean`, `header.jsp`, `action-demo.jsp`, `bean-view.jsp` using `jsp:include`, `jsp:forward`, `jsp:useBean`, `jsp:setProperty`, `jsp:getProperty` - Question 11: `implicit.jsp` and `error.jsp` covering `out`, `request`, `response`, `session`, `pageContext`, `exception` - Question 12: login (`login.jsp`, `LoginServlet`, `LogoutServlet`), `StudentController` with session check, views `students.jsp` and `student-form.jsp` under `WEB-INF/views`, `web.xml` error pages Source: https://syntax.theether.in/mcsl-222/section-2/session-2/index.mdx