Java Servlet Robot Management API: Add, Delete, and Update Robots

This Java Servlet code implements a Robot management API that allows users to perform CRUD (Create, Read, Update, Delete) operations on robot records within a database. The code is structured within the Robot class, which extends the HttpServlet class. This class handles HTTP requests sent to the servlet, which is mapped to the URL path /welcome.

The doPost method of the Robot class is responsible for processing the HTTP POST requests. This method receives an HttpServletRequest object, which contains the request data, and an HttpServletResponse object, which is used to send the response back to the client.

The code first retrieves the action parameter from the request. Based on the value of this parameter, it executes different operations:

1. Add Robot:

   • If the action parameter is 'addRobot', the code creates a new RobotInfo object and sets its properties (name, weight, size) using the corresponding parameters from the request.
   • It then prepares an SQL INSERT statement using a PreparedStatement object.
   • The statement is executed with the robot information, and if the execution is successful, the user is redirected to the ./welcome.jsp page.

2. Delete Robot:

   • If the action parameter is 'deleteRobot', the code retrieves the robotID parameter from the request.
   • It prepares an SQL DELETE statement using a PreparedStatement object, binding the robotID to the statement.
   • The statement is executed, and if successful, the user is redirected to the ./welcome.jsp page.

3. Change Robot:

   • If the action parameter is 'changeRobot', the code retrieves the robotID1, robotname1, robotweight1, and robotsize1 parameters from the request.
   • It prepares an SQL UPDATE statement using a PreparedStatement object, binding the robot information and robotID1 to the statement.
   • The statement is executed, and if successful, the user is redirected to the ./welcome.jsp page.

The code uses a DBConnected class to establish a connection to the database. The PreparedStatement objects are used for secure database interactions, preventing SQL injection vulnerabilities.

This Java Servlet code provides a basic framework for managing robot data in a database. It can be extended to implement more functionalities like retrieving robot records or performing other operations. The use of PreparedStatements ensures secure database operations, while the use of HttpServletRequest and HttpServletResponse objects enables the servlet to handle HTTP requests and responses effectively.