# lokesh-141/servlet architecture

> Architecture diagram of the GitHub repository lokesh-141/servlet, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-06-27). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/lokesh-141/servlet
- Repository: https://github.com/lokesh-141/servlet

## Overview

1. This repository is not one single app; it contains three separate Java EE web applications: `TechBlog`, `Register`, and `feedback_app`. Each is deployed as a servlet/JSP application with its own entry points, views, and packaging boundary.

2. The largest system is `TechBlog`, a classic MVC blog platform. Its runtime boundary is a Java web container such as Tomcat/Glassfish, with HTTP requests entering servlets, business/data access happening in Java classes, and HTML generated by JSP pages.

3. In `TechBlog`, the controller layer lives under `com.tech.blog.servlets`. These servlets handle actions such as login, logout, registration, creating posts, editing posts, and liking posts. They are the main request-routing layer and decide which JSP to render next.

4. The model and persistence boundary is split across `com.tech.blog.entities` and `com.tech.blog.dao`. Entity classes like `User`, `Post`, `Category`, and `Message` represent domain data, while DAO classes encapsulate JDBC-based database operations for users, posts, and likes.

5. `TechBlog` connects to the database through `com.tech.blog.helper.ConnectionProvider`, with `Helper` providing supporting utilities. The README indicates MySQL is the backing store, so the key external dependency is JDBC access from the DAOs to a relational database.

6. The view layer for `TechBlog` sits under `Web Pages`. JSP files such as `index.jsp`, `login_page.jsp`, `register_page.jsp`, `profile.jsp`, `show_blog_page.jsp`, and `load_posts.jsp` render the UI. Static assets are separated into `css`, `js`, `img`, and `pics`, with `normal_navbar.jsp` acting as a reusable UI fragment.

7. Typical `TechBlog` data flow is: browser submits a form or action to a servlet, the servlet validates or transforms request data, calls the relevant DAO, the DAO reads/writes MySQL, and the servlet forwards to a JSP with request/session attributes for rendering. This is the central diagram path for the blog application.

8. The `TechBlog` application also has a standard `WEB-INF/web.xml`, which defines servlet deployment configuration and URL mapping for the container. This reinforces that the app is organized around servlet endpoints rather than a framework like Spring.

9. The `Register` project is a much smaller standalone servlet/JSP demo. Its structure suggests a simple registration flow with `Register.java` as the server-side handler and `signup.jsp` as the form/view, likely intended to demonstrate basic request handling rather than a full domain model.

10. The `feedback_app` is another separate mini-application focused on form submission and request processing. It includes `FirstServlet.java`, `Request1Servlet.java`, and `Request2Servlet.java`, plus JSPs like `feedback.jsp`, `index.jsp`, `header.jsp`, and `links.jsp`; this looks like a teaching/demo app for servlet forwarding, request chaining, and page composition.

11. `feedback_app` also has its own `pom.xml` and `web.xml`, indicating it is independently buildable and deployable from `TechBlog`. Unlike `TechBlog`, there is no DAO/entity/database layer visible, so its main boundary is browser-to-servlet-to-JSP rather than browser-to-servlet-to-database.

12. From an architecture diagram perspective, the main reusable pattern across the repo is: client browser → servlet controller → optional DAO/database → JSP view response. The important distinction is that `TechBlog` uses the full MVC stack with persistence, while `Register` and `feedback_app` are lighter-weight servlet/JSP examples with simpler flows.

Main entry points: [`TechBlog/Source Packages/com.tech.blog.servlets`](https://github.com/lokesh-141/servlet/blob/HEAD/TechBlog/Source%20Packages/com.tech.blog.servlets) (Servlets), [`feedback_app/Request1Servlet.java`](https://github.com/lokesh-141/servlet/blob/main/feedback_app/Request1Servlet.java) (Request1), [`feedback_app/web.xml`](https://github.com/lokesh-141/servlet/blob/main/feedback_app/web.xml) (web.xml), [`TechBlog/Source Packages/com.tech.blog.dao`](https://github.com/lokesh-141/servlet/blob/HEAD/TechBlog/Source%20Packages/com.tech.blog.dao) (DAOs)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_techblog["TechBlog"]
  node_techblog_container["Web Container<br/>runtime"]
  node_techblog_servlets["Servlets<br/>controllers"]
  node_techblog_dao["DAOs<br/>persistence<br/>[com.tech.blog.dao]"]
  node_techblog_entities["Entities<br/>domain model"]
  node_techblog_helper["Helpers<br/>infra utilities"]
  node_techblog_views["JSP Views<br/>presentation"]
  node_techblog_static["Static Assets"]
  node_techblog_db[("MySQL<br/>external database")]
  node_techblog_webxml["web.xml<br/>deployment config<br/>[web.xml]"]
end

subgraph group_register["Register"]
  node_register_handler["Register.java<br/>servlet<br/>[Register.java]"]
  node_register_view["signup.jsp<br/>jsp view<br/>[signup.jsp]"]
end

subgraph group_feedback["feedback_app"]
  node_feedback_entry["FirstServlet<br/>[FirstServlet.java]"]
  node_feedback_chain1["Request1<br/>servlet"]
  node_feedback_chain2["Request2<br/>servlet"]
  node_feedback_views["JSP Pages<br/>presentation<br/>[feedback.jsp]"]
  node_feedback_webxml["web.xml<br/>deployment config<br/>[web.xml]"]
end

node_techblog_container -->|"maps"| node_techblog_webxml
node_techblog_container -->|"dispatches"| node_techblog_servlets
node_techblog_servlets -->|"calls"| node_techblog_dao
node_techblog_servlets -->|"uses"| node_techblog_entities
node_techblog_dao -->|"uses"| node_techblog_helper
node_techblog_helper -->|"connects"| node_techblog_db
node_techblog_dao -->|"reads/writes"| node_techblog_db
node_techblog_servlets -->|"forwards to"| node_techblog_views
node_techblog_views -->|"includes"| node_techblog_static
node_register_handler -->|"renders"| node_register_view
node_feedback_entry -->|"forwards"| node_feedback_chain1
node_feedback_chain1 -->|"chains to"| node_feedback_chain2
node_feedback_entry -->|"renders"| node_feedback_views
node_feedback_chain1 -->|"renders"| node_feedback_views
node_feedback_chain2 -->|"renders"| node_feedback_views
node_feedback_webxml -->|"maps"| node_feedback_entry
node_feedback_webxml -->|"maps"| node_feedback_chain1
node_feedback_webxml -->|"maps"| node_feedback_chain2

click node_techblog_servlets "https://github.com/lokesh-141/servlet/blob/main/TechBlog/Source Packages/com.tech.blog.servlets"
click node_techblog_dao "https://github.com/lokesh-141/servlet/blob/main/TechBlog/Source Packages/com.tech.blog.dao"
click node_techblog_entities "https://github.com/lokesh-141/servlet/blob/main/TechBlog/Source Packages/com.tech.blog.entities"
click node_techblog_helper "https://github.com/lokesh-141/servlet/blob/main/TechBlog/Source Packages/com.tech.blog.helper"
click node_techblog_views "https://github.com/lokesh-141/servlet/tree/main/TechBlog/Web Pages"
click node_techblog_static "https://github.com/lokesh-141/servlet/tree/main/TechBlog/Web Pages/css"
click node_techblog_webxml "https://github.com/lokesh-141/servlet/blob/main/TechBlog/Web Pages/WEB-INF/web.xml"
click node_register_handler "https://github.com/lokesh-141/servlet/blob/main/Register/Register.java"
click node_register_view "https://github.com/lokesh-141/servlet/blob/main/Register/signup.jsp"
click node_feedback_entry "https://github.com/lokesh-141/servlet/blob/main/feedback_app/FirstServlet.java"
click node_feedback_chain1 "https://github.com/lokesh-141/servlet/blob/main/feedback_app/Request1Servlet.java"
click node_feedback_chain2 "https://github.com/lokesh-141/servlet/blob/main/feedback_app/Request2Servlet.java"
click node_feedback_views "https://github.com/lokesh-141/servlet/blob/main/feedback_app/feedback.jsp"
click node_feedback_webxml "https://github.com/lokesh-141/servlet/blob/main/feedback_app/web.xml"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_techblog_container,node_techblog_servlets,node_techblog_dao,node_techblog_entities,node_techblog_helper,node_techblog_views,node_techblog_static,node_techblog_db,node_techblog_webxml toneBlue
class node_register_handler,node_register_view toneAmber
class node_feedback_entry,node_feedback_chain1,node_feedback_chain2,node_feedback_views,node_feedback_webxml toneMint
```

## Components

### TechBlog

Full MVC blog app with servlet controllers, JDBC persistence, and JSP views.

- **Web Container**: runtime · Servlet/JSP runtime boundary for the blog app.
- [Servlets](https://github.com/lokesh-141/servlet/blob/HEAD/TechBlog/Source%20Packages/com.tech.blog.servlets): controllers · Main request-routing layer for login, posts, likes, and registration. · `TechBlog/Source Packages/com.tech.blog.servlets`
- [DAOs](https://github.com/lokesh-141/servlet/blob/HEAD/TechBlog/Source%20Packages/com.tech.blog.dao): persistence · JDBC-based data access for users, posts, and likes. · `TechBlog/Source Packages/com.tech.blog.dao`
- [Entities](https://github.com/lokesh-141/servlet/blob/HEAD/TechBlog/Source%20Packages/com.tech.blog.entities): domain model · Domain objects for users, posts, categories, and messages. · `TechBlog/Source Packages/com.tech.blog.entities`
- [Helpers](https://github.com/lokesh-141/servlet/blob/HEAD/TechBlog/Source%20Packages/com.tech.blog.helper): infra utilities · Database connection and supporting utility classes. · `TechBlog/Source Packages/com.tech.blog.helper`
- [JSP Views](https://github.com/lokesh-141/servlet/tree/HEAD/TechBlog/Web%20Pages): presentation · User-facing pages and reusable JSP fragments. · `TechBlog/Web Pages`
- [Static Assets](https://github.com/lokesh-141/servlet/tree/HEAD/TechBlog/Web%20Pages/css): assets · Styles, scripts, images, and other browser resources. · `TechBlog/Web Pages/css`
- **MySQL**: external database · Relational backing store used by the blog DAOs.
- [web.xml](https://github.com/lokesh-141/servlet/blob/HEAD/TechBlog/Web%20Pages/WEB-INF/web.xml): deployment config · Servlet deployment and URL mapping configuration. · `TechBlog/Web Pages/WEB-INF/web.xml`

### Register

Small standalone servlet/JSP registration demo.

- [Register.java](https://github.com/lokesh-141/servlet/blob/main/Register/Register.java): servlet · Single-handler registration demo endpoint. · `Register/Register.java`
- [signup.jsp](https://github.com/lokesh-141/servlet/blob/main/Register/signup.jsp): jsp view · Registration form and response page. · `Register/signup.jsp`

### feedback_app

Mini servlet/JSP app for request handling and page composition.

- [FirstServlet](https://github.com/lokesh-141/servlet/blob/main/feedback_app/FirstServlet.java): servlet · Primary entry servlet for the feedback demo. · `feedback_app/FirstServlet.java`
- [Request1](https://github.com/lokesh-141/servlet/blob/main/feedback_app/Request1Servlet.java): servlet · Intermediate servlet used for forwarding or chaining. · `feedback_app/Request1Servlet.java`
- [Request2](https://github.com/lokesh-141/servlet/blob/main/feedback_app/Request2Servlet.java): servlet · Downstream servlet in the request-processing chain. · `feedback_app/Request2Servlet.java`
- [JSP Pages](https://github.com/lokesh-141/servlet/blob/main/feedback_app/feedback.jsp): presentation · Feedback forms and composed JSP fragments. · `feedback_app/feedback.jsp`
- [web.xml](https://github.com/lokesh-141/servlet/blob/main/feedback_app/web.xml): deployment config · Servlet mappings for the feedback app. · `feedback_app/web.xml`

## Connections

- Web Container → web.xml: maps · Container reads deployment mappings.
- Web Container → Servlets: dispatches · HTTP requests enter servlet endpoints.
- Servlets → DAOs: calls · Controllers invoke data access for persistence.
- Servlets → Entities: uses · Request data is bound to domain objects.
- DAOs → Helpers: uses · DAOs obtain JDBC connections through helpers.
- Helpers → MySQL: connects · Connection provider reaches the MySQL backend.
- DAOs → MySQL: reads/writes · DAO layer persists blog data in the database.
- Servlets → JSP Views: forwards to · Controllers render the appropriate JSP page.
- JSP Views → Static Assets: includes · Pages reference shared CSS, JS, and images.
- Register.java → signup.jsp: renders · Servlet handles submit and forwards to the JSP.
- FirstServlet → Request1: forwards · Primary servlet passes control to the next step.
- Request1 → Request2: chains to · Request flow continues through a servlet chain.
- FirstServlet → JSP Pages: renders · Servlets compose or return JSP-based feedback pages.
- Request1 → JSP Pages: renders · Intermediate servlet may forward to shared JSPs.
- Request2 → JSP Pages: renders · Downstream servlet completes the response with JSPs.
- web.xml → FirstServlet: maps · Deployment descriptor registers servlet endpoints.
- web.xml → Request1: maps · Deployment descriptor registers servlet endpoints.
- web.xml → Request2: maps · Deployment descriptor registers servlet endpoints.