OneCompiler

JAVA 11

108

11 customer number to a search servlet. && DONAR table

Q1]

customer_search.html:

<!DOCTYPE html> <html> <head> <title>Customer Search</title> </head> <body> <h2>Customer Search</h2> <form action="SearchServlet" method="GET"> <label for="customerNumber">Customer Number:</label> <input type="text" id="customerNumber" name="customerNumber"> <button type="submit">Search</button> </form> </body> </html>

SearchServlet.java:

import java.io.;
import javax.servlet.;
import javax.servlet.http.;
import java.sql.;

public class SearchServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    String customerNumber = request.getParameter("customerNumber");

   
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;

  
    String jdbcURL = "jdbc:mysql://localhost:3306/your_database_name";
    String dbUser = "your_username";
    String dbPassword = "your_password";

    
    PrintWriter out = response.getWriter();
    response.setContentType("text/html");

    try {
    
        Class.forName("com.mysql.jdbc.Driver");

  
        conn = DriverManager.getConnection(jdbcURL, dbUser, dbPassword);

   
        stmt = conn.createStatement();


        String sql = "SELECT * FROM customer WHERE customerNumber = '" + customerNumber + "'";
        rs = stmt.executeQuery(sql);

     
        if (rs.next()) {
         
            out.println("<h2>Customer Details</h2>");
            out.println("<p>Customer Number: " + rs.getString("customerNumber") + "</p>");
            out.println("<p>Customer Name: " + rs.getString("customerName") + "</p>");
            out.println("<p>City: " + rs.getString("city") + "</p>");
            out.println("<p>Country: " + rs.getString("country") + "</p>");
        } else {
         
            out.println("<h2>Error</h2>");
            out.println("<p>Customer with number " + customerNumber + " not found.</p>");
        }
    } catch (SQLException | ClassNotFoundException e) {
       
        e.printStackTrace();
        out.println("<h2>Error</h2>");
        out.println("<p>An error occurred while processing your request.</p>");
    } finally {
       
        try {
            if (rs != null) rs.close();
            if (stmt != null) stmt.close();
            if (conn != null) conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

}

Q2]

import java.sql.*;

public class ColumnInformation {

static final String JDBC_URL = "jdbc:mysql://localhost:3306/your_database_name";
static final String USER = "your_username";
static final String PASSWORD = "your_password";

public static void main(String[] args) {
    try (Connection conn = DriverManager.getConnection(JDBC_URL, USER, PASSWORD)) {
        DatabaseMetaData metaData = conn.getMetaData();

       
        ResultSet rs = metaData.getColumns(null, null, "DONAR", null);
        System.out.println("Columns Information for DONAR table:");
        System.out.println("======================================");
        while (rs.next()) {
            String columnName = rs.getString("COLUMN_NAME");
            String columnType = rs.getString("TYPE_NAME");
            int columnSize = rs.getInt("COLUMN_SIZE");
            boolean isNullable = (rs.getInt("NULLABLE") == DatabaseMetaData.columnNullable);

            System.out.println("Column Name: " + columnName);
            System.out.println("Column Type: " + columnType);
            System.out.println("Column Size: " + columnSize);
            System.out.println("Nullable: " + (isNullable ? "Yes" : "No"));
            System.out.println("--------------------------------------");
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

}