productClass.java Source code

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Here is the source code for productClass.java

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/*
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import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.json.simple.JSONArray;

/**
 *
 * @author c0652863
 */

@WebServlet("/products")
public class productClass extends HttpServlet {

    private Connection getConnection() throws SQLException {

        String url = "jdbc:as400:174.79.32.158";
        String username = "IBM65";
        String password = "IBM65";

        Connection conn = null;
        try {
            Class.forName("com.ibm.as400.access.AS400JDBCDriver");
        } catch (ClassNotFoundException e) {
            System.out.println("Class Not found " + e.getMessage());
        }
        try {
            conn = DriverManager.getConnection(url, username, password);
        } catch (SQLException e) {
            System.out.println("SQL Error " + e.getMessage());
        }
        return conn;
    }

    //Getteing results using JSON
    private String getResults(String query, String... params) {
        String result = new String();
        try (Connection conn = getConnection()) {
            PreparedStatement pstmt = conn.prepareStatement(query);
            for (int i = 1; i <= params.length; i++) {
                pstmt.setString(i, params[i - 1]);
            }
            ResultSet rs = pstmt.executeQuery();
            JSONArray productArr = new JSONArray();
            while (rs.next()) {
                //Mapping the objects
                Map productMapping = new LinkedHashMap();
                productMapping.put("productID", rs.getInt("productID"));
                productMapping.put("name", rs.getString("name"));
                productMapping.put("description", rs.getString("description"));
                productMapping.put("quantity", rs.getInt("quantity"));
                productArr.add(productMapping);
            }
            result = productArr.toString();
        } catch (SQLException ex) {
            Logger.getLogger(productClass.class.getName()).log(Level.SEVERE, null, ex);
        }
        return result.replace("},", "},\n");
    }

    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * Select statement for the database connect to retrieve values
     * 
     * @param request servlet request
     * @param response servlet response
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) {
        try (PrintWriter out = response.getWriter()) {
            if (!request.getParameterNames().hasMoreElements()) {
                out.println(getResults("SELECT * FROM product"));
            } else {
                int productID = Integer.parseInt(request.getParameter("productID"));
                out.println(getResults("SELECT * FROM product WHERE productID = ?", String.valueOf(productID)));
            }
        } catch (IOException ex) {
            Logger.getLogger(productClass.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * 
     * Insertion of values into the database connection
     * 
     * 
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {
        Set<String> keySet = request.getParameterMap().keySet();
        try (PrintWriter out = response.getWriter()) {
            Connection conn = getConnection();
            if (keySet.contains("name") && keySet.contains("description") && keySet.contains("quantity")) {
                PreparedStatement pstmt = conn.prepareStatement(
                        "INSERT INTO product(productID, name, description, quantity) " + "VALUES (null, '"
                                + request.getParameter("name") + "', '" + request.getParameter("description")
                                + "', " + request.getParameter("quantity") + ");");
                try {
                    pstmt.executeUpdate();
                    request.getParameter("productID");
                    doGet(request, response);
                } catch (SQLException ex) {
                    Logger.getLogger(productClass.class.getName()).log(Level.SEVERE, null, ex);
                    out.println("Data inserted Error while retriving data.");
                }
            } else {
                out.println("Error: Not enough data to input");
            }
        } catch (SQLException ex) {
            Logger.getLogger(productClass.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    /*
    * Update statement 
    * To change the values inthe database
    *
    */
    @Override
    protected void doPut(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {
        Set<String> keySet = request.getParameterMap().keySet();
        try (PrintWriter out = response.getWriter()) {
            Connection conn = getConnection();
            if (keySet.contains("productID") && keySet.contains("name") && keySet.contains("description")
                    && keySet.contains("quantity")) {
                PreparedStatement pstmt = conn.prepareStatement("UPDATE product SET name='"
                        + request.getParameter("name") + "',`description`='" + request.getParameter("description")
                        + "',quantity=" + request.getParameter("quantity") + " WHERE `productID`="
                        + request.getParameter("productID"));
                try {
                    pstmt.executeUpdate();
                    doGet(request, response); //shows updated row
                } catch (SQLException ex) {
                    Logger.getLogger(productClass.class.getName()).log(Level.SEVERE, null, ex);
                    out.println("Error putting values.");
                }
            } else {
                out.println("Error: Not enough data to update");
            }
        } catch (SQLException ex) {
            Logger.getLogger(productClass.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    //    Delete Statement
    //    Used to delete data from the database
    @Override
    protected void doDelete(HttpServletRequest request, HttpServletResponse response) throws IOException {
        Set<String> keySet = request.getParameterMap().keySet();
        try (PrintWriter out = response.getWriter()) {
            Connection conn = getConnection();
            if (keySet.contains("productID")) {
                PreparedStatement pstmt = conn.prepareStatement(
                        "DELETE FROM `product` WHERE `productID`=" + request.getParameter("productID"));
                try {
                    pstmt.executeUpdate();
                } catch (SQLException ex) {
                    Logger.getLogger(productClass.class.getName()).log(Level.SEVERE, null, ex);
                    out.println("Error in deleting the product.");
                }
            } else {
                out.println("Error: in data to delete");
            }
        } catch (SQLException ex) {
            Logger.getLogger(productClass.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

}