updateservlet.java

来自「JAVA Servlet2.3外文书籍源码」· Java 代码 · 共 74 行

package jsp;

import javax.servlet.ServletException;
import javax.servlet.ServletConfig;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import javax.sql.DataSource;

import javax.naming.InitialContext;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class UpdateServlet extends HttpServlet {

  public void init(ServletConfig config) throws ServletException {
      super.init(config);
  }
  
  public void doPost(HttpServletRequest req, HttpServletResponse res)
      throws ServletException {
    doGet(req, res);
  }

  public void doGet(HttpServletRequest req, HttpServletResponse res)
     throws ServletException {
      
    Connection con = null;
    
    try {
        
      InitialContext ctx = new InitialContext();
      DataSource ds = 
      (DataSource)ctx.lookup("java:comp/env/jdbc/inventoryDB");
      
      con = ds.getConnection();
      PreparedStatement stmt = con.prepareStatement("update item " + 
                                                    "set name = ?, " + 
                                                    "description = ?, " + 
                                                    "price = ?, " + 
                                                    "stock = ? " +
                                                    "where id = ?");
      
      stmt.setString(1, req.getParameter("name"));
      stmt.setString(2, req.getParameter("description"));
      stmt.setDouble(3, Double.parseDouble(req.getParameter("price")));
      stmt.setInt(4, Integer.parseInt(req.getParameter("stock")));
      stmt.setInt(5, Integer.parseInt(req.getParameter("id")));
      stmt.executeUpdate();            
      stmt.close();           
      
      getServletContext().getRequestDispatcher("/List").
      forward(req, res);
        
    } catch(Exception ex) {
      throw new ServletException(ex);
    } finally {
      try {
        if(con != null) {
          con.close();
        }
      }catch(Exception ex) {
        throw new ServletException(ex);
      }
    }
      
  }

}