ordersbean.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 OrdersBean implements EntityBean
{
  java.lang.String orderID;
  java.lang.String customerID;
  java.lang.String bookID;
  int num;
  java.sql.Date orderDate;
  java.sql.Date deliverDate;

  private Connection con=null;
  EntityContext entityContext;
  /**********************business methods**************************************/
  public void setOrderID(java.lang.String orderID) {
    this.orderID = orderID;
  }
  public void setCustomerID(java.lang.String customerID) {
    this.customerID = customerID;
  }
  public void setBookID(java.lang.String bookID) {
    this.bookID = bookID;
  }
  public void setNum(int num) {
    this.num = num;
  }
  public void setOrderDate(java.sql.Date orderDate) {
    this.orderDate = orderDate;
  }
  public void setDeliverDate(java.sql.Date deliverDate) {
    this.deliverDate = deliverDate;
  }
  public java.lang.String getOrderID() {
    return orderID;
  }
  public java.lang.String getCustomerID() {
    return customerID;
  }
  public java.lang.String getBookID() {
    return bookID;
  }
  public int getNum() {
    return num;
  }
  public java.sql.Date getOrderDate() {
    return orderDate;
  }
  public java.sql.Date getDeliverDate() {
    return deliverDate;
  }
  public OrderDetails getDetails()
   {
      System.out.println("CustomerBean getDetails");

      return new OrderDetails (orderID,customerID,bookID,
             num, orderDate,deliverDate);
   }//getDetails

  /**********************************ejb methods*************************/
  public java.lang.String ejbCreate(OrderDetails orderValue)
      throws CreateException
  {
    System.out.println("orderBean ejbCreate");

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

        this.customerID=orderValue.getCustomerID();
        this.bookID=orderValue.getBookID();
        this.num=orderValue.getNum();
        this.orderDate=orderValue.getOrderDate();
        this.deliverDate=orderValue.getDeliverDate();

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

        return orderID;

  }
  public void ejbPostCreate(OrderDetails orderValue) throws CreateException
  {
    System.out.println("orderBean ejbPostCreate");
  }

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

    Collection result;

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

  }

  public java.util.Collection ejbFindOrderAble(String SQLStatement) throws FinderException {
    System.out.println("orderBean ejbFindOrderAble");

    Collection result;

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

  }


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

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

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

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

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

      public void ejbStore()
      {

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

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

  public void ejbActivate()
  {
        System.out.println("orderBean ejbActivate");
        orderID = (String)entityContext.getPrimaryKey();
    }

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

        orderID= null;
    }

  public void unsetEntityContext()
  {
    System.out.println("orderBean ussetEntiyContext");
    this.entityContext = null;
  }
  public void setEntityContext(EntityContext entityContext) {
    System.out.println("orderBean setEntiyContext");
    this.entityContext = entityContext;
  }
  /******************************util methods*************************/
  private void makeConnection() {

        System.out.println("orderBean 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("orderBean makeConnection out");
    } // makeConnection


    private void releaseConnection() {

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

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

    } // releaseConnection


    private void insertRow () throws SQLException {

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

        makeConnection();

        String insertStatement =
            "insert into orders values ( ? , ? , ? , ? , ? , ?)";
        PreparedStatement prepStmt =
            con.prepareStatement(insertStatement);

        String updateStatement =
               "update book " +
               "set StockNum =StockNum- ?"+
               "where bookID = ? ";
       PreparedStatement prepUpdateStmt =
               con.prepareStatement(updateStatement);

        prepStmt.setString(1, orderID);
        prepStmt.setString(2,customerID);
        prepStmt.setString(3, bookID);
        prepStmt.setInt(4, num);
        prepStmt.setDate(5,orderDate);
        prepStmt.setDate(6,deliverDate);

        prepUpdateStmt.setInt(1,num);
        prepUpdateStmt.setString(2, bookID);

        int rowCount = prepUpdateStmt.executeUpdate();
        prepUpdateStmt.close();

        if (rowCount == 0) {
            throw new EJBException("insertRow: updating table Book failed.");
        }

        prepStmt.executeUpdate();
        prepStmt.close();

        releaseConnection();
        System.out.println("orderBean insertRow out");
    }//insertRow

    private Collection selectByCondition(String condition) throws SQLException {

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

       makeConnection();
       String selectStatement =
               "select orderID " +
               "from orders 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("orderBean selectByCondition out");
       return a;
   }//selectByCondition

   private Collection selectOrderAble(String SQLStatement) throws SQLException {

       System.out.println("orderBean selectOrderAble in");

       makeConnection();

       System.out.println(SQLStatement);
       Statement stmt=con.createStatement();
       ResultSet rs=stmt.executeQuery(SQLStatement);

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

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


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

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

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

    private void loadOrder() throws SQLException {

        System.out.println("orderBean loadorder in");

        makeConnection();
        String selectStatement =
                "select customerID,bookID, num,orderDate,deliverDate " +
                "from orders where orderID = ? ";
        PreparedStatement prepStmt =
                con.prepareStatement(selectStatement);

        prepStmt.setString(1, orderID);

        ResultSet rs = prepStmt.executeQuery();

        if (rs.next())
        {
            customerID = rs.getString(1);
            bookID = rs.getString(2);
            num = rs.getInt(3);
            orderDate=rs.getDate(4);
            deliverDate=rs.getDate(5);

            prepStmt.close();
            releaseConnection();
        }
        else {
            prepStmt.close();
            releaseConnection();
            throw new NoSuchEntityException("loadorder:Row for id " +
                orderID + " not found in database.");
        }
        System.out.println("orderBean loadorder out");
    }//loadorder

    private void storeOrder() throws SQLException {

        System.out.println("orderBean storeorder in");

        makeConnection();

        String updateStatement =
                "update orders " +
                "set customerID = ? , bookID = ? , num = ? , orderDate = ? ,deliverDate = ?"+
                "where orderID = ? ";
        PreparedStatement prepStmt =
                con.prepareStatement(updateStatement);

        prepStmt.setString(1,customerID);
        prepStmt.setString(2, bookID);
        prepStmt.setInt(3, num);
        prepStmt.setDate(4,orderDate);
        prepStmt.setDate(5,deliverDate);
        prepStmt.setString(6, orderID);

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

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

    private void deleteRow(String id) throws SQLException {

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

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

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

}