basketbean.java

一个java

package bookstore.ejb;

import bookstore.util.*;

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


public class BasketBean implements EntityBean {
  java.lang.String basketID;
  java.lang.String customerID;
  java.lang.String bookID;
  java.sql.Date addDate;

  private Connection con=null;
  EntityContext entityContext;
  /*********************business methods***************************/
  public void setBasketID(java.lang.String basketID) {
    this.basketID = basketID;
  }
  public void setCustomerID(java.lang.String customerID) {
    this.customerID = customerID;
  }
  public void setBookID(java.lang.String bookID) {
    this.bookID = bookID;
  }
  public void setAddDate(java.sql.Date addDate) {
    this.addDate = addDate;
  }
  public java.lang.String getBasketID() {
    return basketID;
  }
  public java.lang.String getCustomerID() {
    return customerID;
  }
  public java.lang.String getBookID() {
    return bookID;
  }
  public java.sql.Date getAddDate() {
    return addDate;
  }

  public BasketDetails getDetails()
   {
      System.out.println("BasketBean getDetails");

      return new BasketDetails (basketID,customerID ,bookID,addDate);
   }//getDetails

  /********************************ejb methods**************************/
  public java.lang.String ejbCreate(BasketDetails basketValue) throws CreateException {
    System.out.println("basketBean ejbCreate");

        try
        {
          makeConnection();
          this.basketID=DBHelper.getNextBasketID(con);
        }catch(Exception ex)
        {
          throw new EJBException("ejbCreate: "+ex.getMessage());
        }

        this.customerID=basketValue.getCustomerID();
        this.bookID=basketValue.getBookID();
        this.addDate=basketValue.getAddDate();

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

        return basketID;

  }

  public void ejbPostCreate(BasketDetails basketValue) throws CreateException {
    System.out.println("basketBean ejbPostCreate");
  }

  public java.util.Collection ejbFindByCondition(String condition) throws FinderException {
    System.out.println("basketBean ejbFindByCondition");

    Collection result;

    try {
           result = selectByCondition(condition);
       } catch (Exception ex) {
             throw new EJBException("ejbFindByCondition " +
                 ex.getMessage());
       }
       return result;

  }

  public void ejbRemove() throws RemoveException {
    System.out.println("basketBean ejbRemove");

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

  public java.lang.String ejbFindByPrimaryKey(java.lang.String primaryKey) throws FinderException {

         System.out.println("basketBean ejbFindByPrimaryKey");

         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 ejbLoad() {

          System.out.println("basketBean ejbLoad");

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

      public void ejbStore()
      {

            System.out.println("basketBean ejbStore");

            try {
                storeBasket();
             } catch (Exception ex) {
                  throw new EJBException("ejbStore: " +
                      ex.getMessage());
             }
        }//ejbStore

  public void ejbActivate()
  {
        System.out.println("basketBean ejbActivate");
        //
        basketID = (String)entityContext.getPrimaryKey();
    }

    public void ejbPassivate()
    {
        System.out.println("basketBean ejbPassivate");

        basketID= null;
    }

  public void unsetEntityContext()
  {
    System.out.println("basketBean ussetEntiyContext");
    this.entityContext = null;
  }
  public void setEntityContext(EntityContext entityContext) {
    System.out.println("basketBean setEntiyContext");
    this.entityContext = entityContext;
  }

  /****************************util methods*******************************/
  private void makeConnection() {

        System.out.println("BasketBean makeConnection in");
        try
           {
             InitialContext ic = new InitialContext();
             DataSource ds = (DataSource) ic.lookup("DBSource");
             con = ds.getConnection();
           }
           catch (Exception ex)
           {
             throw new EJBException("Unable to connect to database. " +
                                   ex.getMessage());
           }
        System.out.println("BasketBean makeConnection out");
    } // makeConnection


    private void releaseConnection() {

        System.out.println("BasketBean releaseConnection in");

        try {
            con.close();
        } catch (SQLException ex) {
             throw new EJBException("releaseConnection: " + ex.getMessage());
        }
        System.out.println("BasketBean releaseConnection out");

    } // releaseConnection


    private void insertRow () throws SQLException {

        System.out.println("basketBean insertRow in");

        makeConnection();
        String insertStatement =
            "insert into basket values ( ? , ? , ? , ? )";
        PreparedStatement prepStmt =
            con.prepareStatement(insertStatement);
        prepStmt.setString(1, basketID);
        prepStmt.setString(2, customerID);
        prepStmt.setString(3, bookID);
        prepStmt.setDate(4,addDate);

        prepStmt.executeUpdate();
        prepStmt.close();
        releaseConnection();
        System.out.println("BasketBean insertRow out");
    }//insertRow

    private Collection selectByCondition(String condition) throws SQLException {

       System.out.println("BasketBean selectByCondition in");

       makeConnection();
       String selectStatement =
               "select basketID " +
               "from basket where "+condition;
       System.out.println(selectStatement);
       Statement stmt=con.createStatement();
       ResultSet rs=stmt.executeQuery(selectStatement);

       ArrayList a = new ArrayList();
       while (rs.next())
       {
           a.add(rs.getString(1));
       }

       stmt.close();
       releaseConnection();
       System.out.println("basketBean selectByCondition out");
       return a;
   }//selectByCondition

   private boolean selectByPrimaryKey(String primaryKey) throws SQLException {
        //本函数主要目的还在于确保basket_id在数据库表中是存在的
        System.out.println("basketBean selectByPrimaryKey in");

        makeConnection();
        //a question here
        String selectStatement =
                "select basketID " +
                "from basket where basketID = ? ";
        PreparedStatement prepStmt =
                con.prepareStatement(selectStatement);
        prepStmt.setString(1, primaryKey);

        ResultSet rs = prepStmt.executeQuery();
        boolean result = rs.next();
        prepStmt.close();
        releaseConnection();
        System.out.println("basketBean selectByPrimaryKey out");
        return result;
    }//selectByPrimaryKey

    private void loadBasket() throws SQLException {

        System.out.println("basketBean loadbasket in");

        makeConnection();
        String selectStatement =
                "select CustomerID, BookID,addDate " +
                "from basket where basketID = ? ";
        PreparedStatement prepStmt =
                con.prepareStatement(selectStatement);

        prepStmt.setString(1, basketID);

        ResultSet rs = prepStmt.executeQuery();

        if (rs.next())
        {
            customerID = rs.getString(1);
            bookID = rs.getString(2);
            addDate=rs.getDate(3);
            prepStmt.close();
            releaseConnection();
        }
        else {
            prepStmt.close();
            releaseConnection();
            throw new NoSuchEntityException("loadbasket:Row for id " +
                basketID + " not found in database.");
        }
        System.out.println("basketBean loadbasket out");
    }//loadbasket

    private void storeBasket() throws SQLException {

        System.out.println("basketBean storebasket in");

        makeConnection();

        String updateStatement =
                "update basket " +
                "set customerID = ? , bookID = ? , addDate = ? " +
                "where basketID = ? ";
        PreparedStatement prepStmt =
                con.prepareStatement(updateStatement);

        prepStmt.setString(1,customerID);
        prepStmt.setString(2, bookID);
        prepStmt.setDate(3,addDate);
        prepStmt.setString(4, basketID);

        int rowCount = prepStmt.executeUpdate();
        prepStmt.close();
        releaseConnection();

        if (rowCount == 0) {
            throw new EJBException("storebasket:Storing row for id " + basketID + " failed.");
        }
        System.out.println("basketBean storebasket out");
    }//storebasket

    private void deleteRow(String id) throws SQLException {

        System.out.println("basketBean deleteRow in");

        makeConnection();
        String deleteStatement =
                "delete from basket where basketID = ? ";
        PreparedStatement prepStmt =
                con.prepareStatement(deleteStatement);

        prepStmt.setString(1, id);
        prepStmt.executeUpdate();
        prepStmt.close();
        releaseConnection();
        System.out.println("basketBean deleteRow out");
    }////deleteRow

}