widgetbean.java

一个java写的加密算法

/*
 * Copyright 2004-2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

package samples.ejb.bmp.simple.ejb;

import java.sql.*;
import javax.sql.*;
import java.util.*;
import javax.ejb.*;
import javax.naming.*;

public class WidgetBean implements EntityBean {

   private String widgetId;
   private String description;
   private double price;
   private EntityContext context;
   private DataSource dataSource;


   public String getDescription() {

      return description;
   }

   public double getPrice() {

      return price;
   }

   public String ejbCreate(String widgetId, String description,
      double price)
      throws CreateException {

      try {
         insertRow(widgetId, description, price);
      } catch (Exception ex) {
          throw new EJBException("ejbCreate: " +
             ex.getMessage());
      }

      this.widgetId = widgetId;
      this.description = description;
      this.price = price;

      return widgetId;
    }

   public String ejbFindByPrimaryKey(String primaryKey)
      throws FinderException {

      boolean result;

      try {
         result = selectByPrimaryKey(primaryKey);
       } catch (Exception ex) {
           throw new EJBException("ejbFindByPrimaryKey: " +
              ex.getMessage());
       }

      if (result) {
         return primaryKey;
      }
      else {
         throw new ObjectNotFoundException
            ("Row for id " + primaryKey + " not found.");
      }
   }

   public void ejbRemove() {

      try {
         deleteRow(widgetId);
       } catch (Exception ex) {
           throw new EJBException("ejbRemove: " +
              ex.getMessage());
       }
   }

   public void setEntityContext(EntityContext context) {

      this.context = context;
      try {
        InitialContext ic = new InitialContext();
        dataSource = (DataSource) ic.lookup("java:comp/env/jdbc/bmp-simple");
      } catch (Exception ex) {
          throw new EJBException("Unable to connect to database. " +
             ex.getMessage());
      }
   }

   public void unsetEntityContext() {
      this.context = null;
   }

   public void ejbActivate() {

      widgetId = (String)context.getPrimaryKey();
   }

   public void ejbPassivate() {

      widgetId = null;
   }

   public void ejbLoad() {

      try {
         loadRow();
       } catch (Exception ex) {
           throw new EJBException("ejbLoad: " +
              ex.getMessage());
       }
   }

   public void ejbStore() {

      try {
         storeRow();
       } catch (Exception ex) {
           throw new EJBException("ejbLoad: " +
              ex.getMessage());
       }
   }


   public void ejbPostCreate(String widgetId, String description,
      double price) { }


/*********************** Database Routines *************************/

   private void insertRow(String widgetId, String description, double price) throws SQLException {
       Connection con = null;
       PreparedStatement prepStmt = null;
       try {
           con = dataSource.getConnection();
           String insertStatement =
           "insert into widget values ( ? , ? , ? )";
           prepStmt = con.prepareStatement(insertStatement);
           
           prepStmt.setString(1, widgetId);
           prepStmt.setString(2, description);
           prepStmt.setDouble(3, price);
           
           prepStmt.executeUpdate();
           prepStmt.close();
           con.close();
       } catch (Exception e) {
       } finally {
           if (prepStmt != null) {
               try {
                   prepStmt.close();
               } catch (Exception e){
               }
           }
           if (con != null) {
               try {
                   con.close();
               } catch (Exception e){
               }
           }
       }
   }

   private void deleteRow(String widgetId) throws SQLException {
       Connection con = null;
       PreparedStatement prepStmt = null;
       try {
           con = dataSource.getConnection();
           String deleteStatement =
           "delete from widget where widgetid = ? ";
           prepStmt = con.prepareStatement(deleteStatement);
           
           prepStmt.setString(1, widgetId);
           prepStmt.executeUpdate();
           prepStmt.close();
           con.close();
       } catch (Exception e) {
       } finally {
           if (prepStmt != null) {
               try {
                   prepStmt.close();
               } catch (Exception e){
               }
           }
           if (con != null) {
               try {
                   con.close();
               } catch (Exception e){
               }
           }
       }
   }

   private boolean selectByPrimaryKey(String primaryKey) throws SQLException {
       Connection con = null;
       PreparedStatement prepStmt = null;
       boolean result = false;
       try {
           con = dataSource.getConnection();
           String selectStatement =
           "select widgetid " +
           "from widget where widgetid = ? ";
           prepStmt = con.prepareStatement(selectStatement);
           prepStmt.setString(1, primaryKey);
           
           ResultSet rs = prepStmt.executeQuery();
           result = rs.next();
           prepStmt.close();
           con.close();
           return result;
       } catch (Exception e) {
           return result;
       } finally {
           if (prepStmt != null) {
               try {
                   prepStmt.close();
               } catch (Exception e){
               }
           }
           if (con != null) {
               try {
                   con.close();
               } catch (Exception e){
               }
           }
       }
   }

   private void loadRow() throws SQLException {
       Connection con = null;
       PreparedStatement prepStmt = null;
       try {           
           con = dataSource.getConnection();
           String selectStatement =
           "select description, price " +
           "from widget where widgetid = ? ";
           prepStmt = con.prepareStatement(selectStatement);
           
           prepStmt.setString(1, this.widgetId);
           
           ResultSet rs = prepStmt.executeQuery();
           
           if (rs.next()) {
               this.description = rs.getString(1);
               this.price = rs.getDouble(2);
               prepStmt.close();
           }
           else {
               prepStmt.close();
               throw new NoSuchEntityException("Row for widgetId " + widgetId +
               " not found in database.");
           }
           con.close();
       } catch (Exception e) {
       } finally {
           if (prepStmt != null) {
               try {
                   prepStmt.close();
               } catch (Exception e){
               }
           }
           if (con != null) {
               try {
                   con.close();
               } catch (Exception e){
               }
           }
       }
   }


   private void storeRow() throws SQLException {
       Connection con = null;
       PreparedStatement prepStmt = null;
       try {
           con = dataSource.getConnection();
           String updateStatement =
           "update widget set description =  ? , " +
           "price = ? " +
           "where widgetid = ?";
           prepStmt = con.prepareStatement(updateStatement);
           
           prepStmt.setString(1, description);
           prepStmt.setDouble(2, price);
           prepStmt.setString(3, widgetId);
           int rowCount = prepStmt.executeUpdate();
           prepStmt.close();
           con.close();
           
           if (rowCount == 0) {
               throw new EJBException("Storing row for widgetId " +
               widgetId + " failed.");
           }
       } catch (Exception e) {           
       } finally {
           if (prepStmt != null) {
               try { 
                   prepStmt.close();
               } catch (Exception e){
               }
           }
           if (con != null) {
               try {
                   con.close();
               } catch (Exception e){
               }
           }
       }

   }

} // WidgetBean