/* * * Copyright 2001 Sun Microsystems, Inc. All Rights Reserved. *  * This software is the proprietary information of Sun Microsystems, Inc.   * Use is subject to license terms. *  */import java.sql.*;import javax.sql.*;import java.util.*;import javax.ejb.*;import javax.naming.*;public class SavingsAccountBean implements EntityBean {    private String id;    private String firstName;    private String lastName;    private double balance;    private EntityContext context;    private Connection con;    private String dbName = "java:comp/env/jdbc/SavingsAccountDB";    public void debit(double amount)        throws InsufficientBalanceException {       if (balance - amount < 0) {           throw new InsufficientBalanceException();       }       balance -= amount;    }    public void credit(double amount) {       balance += amount;    }     public String getFirstName() {        return firstName;    }     public String getLastName() {        return lastName;    }      public double getBalance() {       return balance;    }    public String ejbCreate(String id, String firstName,        String lastName, double balance)       throws CreateException {       if (balance < 0.00) {          throw new CreateException             ("A negative initial balance is not allowed.");       }       try {          insertRow(id, firstName, lastName, balance);       } catch (Exception ex) {           throw new EJBException("ejbCreate: " +               ex.getMessage());       }       this.id = id;       this.firstName = firstName;       this.lastName = lastName;       this.balance = balance;       return id;    }   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 Collection ejbFindByLastName(String lastName)      throws FinderException {      Collection result;      try {         result = selectByLastName(lastName);       } catch (Exception ex) {           throw new EJBException("ejbFindByLastName " +               ex.getMessage());       }       return result;   }   public Collection ejbFindInRange(double low, double high)      throws FinderException {      Collection result;      try {         result = selectInRange(low, high);                   } catch (Exception ex) {           throw new EJBException("ejbFindInRange: " +               ex.getMessage());       }      return result;   }   public void ejbRemove() {      try {         deleteRow(id);       } catch (Exception ex) {           throw new EJBException("ejbRemove: " +               ex.getMessage());       }   }    public void setEntityContext(EntityContext context) {      this.context = context;      try {         makeConnection();      } catch (Exception ex) {          throw new EJBException("Unable to connect to database. " +             ex.getMessage());      }   }   public void unsetEntityContext() {      try {         con.close();      } catch (SQLException ex) {          throw new EJBException("unsetEntityContext: " + ex.getMessage());      }   }   public void ejbActivate() {      id = (String)context.getPrimaryKey();   }   public void ejbPassivate() {      id = 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("ejbStore: " +               ex.getMessage());       }   }   public void ejbPostCreate(String id, String firstName,       String lastName, double balance) { }/*********************** Database Routines *************************/   private void makeConnection() throws NamingException, SQLException {      InitialContext ic = new InitialContext();      DataSource ds = (DataSource) ic.lookup(dbName);      con =  ds.getConnection();   }   private void insertRow (String id, String firstName, String lastName,                            double balance) throws SQLException {          String insertStatement =                "insert into savingsaccount values ( ? , ? , ? , ? )";          PreparedStatement prepStmt =                 con.prepareStatement(insertStatement);          prepStmt.setString(1, id);          prepStmt.setString(2, firstName);          prepStmt.setString(3, lastName);          prepStmt.setDouble(4, balance);          prepStmt.executeUpdate();          prepStmt.close();   }   private void deleteRow(String id) throws SQLException {      String deleteStatement =            "delete from savingsaccount where id = ? ";      PreparedStatement prepStmt =            con.prepareStatement(deleteStatement);      prepStmt.setString(1, id);      prepStmt.executeUpdate();      prepStmt.close();   }   private boolean selectByPrimaryKey(String primaryKey)       throws SQLException {      String selectStatement =            "select id " +            "from savingsaccount where id = ? ";      PreparedStatement prepStmt =            con.prepareStatement(selectStatement);      prepStmt.setString(1, primaryKey);      ResultSet rs = prepStmt.executeQuery();      boolean result = rs.next();      prepStmt.close();      return result;   }   private Collection selectByLastName(String lastName)       throws SQLException {      String selectStatement =            "select id " +            "from savingsaccount where lastname = ? ";      PreparedStatement prepStmt =             con.prepareStatement(selectStatement);      prepStmt.setString(1, lastName);      ResultSet rs = prepStmt.executeQuery();      ArrayList a = new ArrayList();      while (rs.next()) {         String id = rs.getString(1);         a.add(id);      }      prepStmt.close();      return a;   }   private Collection selectInRange(double low, double high)       throws SQLException {      String selectStatement =            "select id from savingsaccount " +            "where balance between  ? and ?";      PreparedStatement prepStmt =             con.prepareStatement(selectStatement);      prepStmt.setDouble(1, low);      prepStmt.setDouble(2, high);      ResultSet rs = prepStmt.executeQuery();      ArrayList a = new ArrayList();      while (rs.next()) {         String id = rs.getString(1);         a.add(id);      }      prepStmt.close();      return a;   }   private void loadRow() throws SQLException {      String selectStatement =            "select firstname, lastname, balance " +            "from savingsaccount where id = ? ";      PreparedStatement prepStmt =             con.prepareStatement(selectStatement);      prepStmt.setString(1, this.id);      ResultSet rs = prepStmt.executeQuery();      if (rs.next()) {         this.firstName = rs.getString(1);         this.lastName = rs.getString(2);         this.balance = rs.getDouble(3);         prepStmt.close();      }      else {         prepStmt.close();         throw new NoSuchEntityException("Row for id " + id +            " not found in database.");      }   }   private void storeRow() throws SQLException {      String updateStatement =            "update savingsaccount set firstname =  ? ," +            "lastname = ? , balance = ? " +            "where id = ?";      PreparedStatement prepStmt =             con.prepareStatement(updateStatement);      prepStmt.setString(1, firstName);      prepStmt.setString(2, lastName);      prepStmt.setDouble(3, balance);      prepStmt.setString(4, id);      int rowCount = prepStmt.executeUpdate();      prepStmt.close();      if (rowCount == 0) {         throw new EJBException("Storing row for id " + id + " failed.");      }   }} // SavingsAccountBean