AutoAccountHome.create(), the container (which in WebLogic EJB is
* also the home) allocates an instance of this EJBean and
* calls AutoAccountBean.ejbCreate().
*
* For container-managed persistence, ejbCreate() returns
* a void, unlike the case of bean-managed
* persistence, where it returns a primary key.
*
* @param accountID String Account ID
* @param initialBalance double Initial Balance
* @exception javax.ejb.CreateException
* if there is a problem creating the bean
*/
public void ejbCreate(String accountId, double initialBalance)
throws CreateException
{
if (VERBOSE)
System.out.println("AccountBean.ejbCreate( id = " + System.identityHashCode(this) + ", PK = " +
accountId + ", " + "initial balance = $ " + initialBalance + ")");
this.accountId = accountId;
this.balance = initialBalance;
}
/**
* This method corresponds to the create method in the home interface
* "AutoAccountHome.java".
* The parameter sets of the two methods are identical. When the client calls
* AutoAccountHome.create(), the container (which in WebLogic EJB is
* also the home) allocates an instance of this bean and
* calls AutoAccountBean.ejbCreate().
*
* For bean-managed persistence, ejbCreate() returns
* a primary key, unlike the case of container-managed
* persistence, where it returns a void.
*
* Unlike the ejbCreate(String accountId, double initialBalance),
* this version creates a new AccountID using getNewAccountId().
*
* @param initialBalance double Initial Balance
* @exception javax.ejb.CreateException
* if there is a problem getting an account ID
*/
public void ejbCreate(double initialBalance)
throws CreateException
{
try {
ejbCreate(getNewAccountId(), initialBalance);
} catch (Exception e) {
throw new CreateException (e.getMessage());
}
}
/**
* This method gets the next account ID. If there are no
* more IDs available in the current range, it goes to the
* database and retreives a new range of IDs.
* The range is set by a parameter in the Deployment Descriptor.
* The current range of available IDs is stored in
* lastKey and maxKey.
*
* @return String Next account ID
* @exception Exception
* if there is a problem getting an account ID
*/
private String getNewAccountId() throws Exception {
if (VERBOSE)
System.out.println("getNewAccountId(); lastKey: " + lastKey + " maxKey: " + maxKey);
if (lastKey >= maxKey) {
// Go to database and set new values for lastKey and maxKey
if (VERBOSE)
System.out.println("lastKey>=maxKey: getting new range of accountIds");
Connection con = null;
Statement stat = null;
ResultSet results = null;
String idTableName = getIdTableName();
String tableName = getJdbcProperty("tableName");
int range = getRange();
int dbMaxKey;
int newMaxKey;
try {
con = getConnection();
stat = con.createStatement();
int i;
stat.executeQuery("select maxKey from " + idTableName +
" where tablename = '" + tableName + "'");
results = stat.getResultSet();
if ((results != null) && (results.next())) {
dbMaxKey = results.getInt(1);
newMaxKey = dbMaxKey + range;
i = stat.executeUpdate("update " + idTableName +
" set maxKey = " + new Integer(newMaxKey).toString() +
" where tablename = '" + tableName + "'");
if (i == 0) {
throw new CreateException ("ejbCreate: idTableName (" + idTableName + ") not updated");
}
} else {
dbMaxKey = maxKey;
newMaxKey = maxKey + range;
i = stat.executeUpdate("insert into " + idTableName +
" (tablename, maxKey) values ('" + tableName +
"', " + new Integer(newMaxKey).toString() + ")");
if (i == 0) {
throw new CreateException ("ejbCreate: idTableName (" + idTableName +
") not inserted");
}
}
lastKey = dbMaxKey;
maxKey = newMaxKey;
}
catch (SQLException sqe) {
throw new CreateException (sqe.getMessage());
}
finally {
if (stat != null)
try { stat.close();} catch (Exception e) {}
if (con != null)
try { con.close();} catch (Exception e) {}
if (results != null)
try { results.close();} catch (Exception e) {}
}
}
return new Integer(++lastKey).toString();
}
/**
* This method is required by the EJB Specification,
* but is not used by this example.
*
* @param accountID String Account Identification
* @param initialBalance double Initial Balance
*/
public void ejbPostCreate(String accountId, double initialBalance) {
if (VERBOSE)
System.out.println("ejbPostCreate (" + id() + ")");
}
/**
* This method is required by the EJB Specification,
* but is not used by this example.
*
* @param initialBalance double Initial Balance
*/
public void ejbPostCreate(double initialBalance) {
if (VERBOSE)
System.out.println("ejbPostCreate (" + id() + ")");
}
// Application defined methods
/**
* Adds amount to balance.
*
* @param amount double Amount
* @return double balance
*/
public double deposit(double amount) {
if (VERBOSE)
System.out.println("Depositing $" + amount + " into '" + accountId + "'");
balance += amount;
return balance;
}
/**
* Subtracts amount from balance.
*
* @param amount double Amount
* @return double Balance
* @exception ProcessingErrorException
* if Amount > Balance
*/
public double withdraw(double amount)
throws ProcessingErrorException
{
if (VERBOSE)
System.out.println("Withdrawing $" + amount + " from '" + accountId + "'");
if (amount > balance) {
throw new ProcessingErrorException("Request to withdraw $" + amount +
" more than balance " + balance +
" in account " + accountId);
}
balance -= amount;
return balance;
}
/**
* Returns current balance.
*
* @return double Balance
*/
public double balance() {
return balance;
}
/**
* Returns account ID.
*
* @return String Account ID
*/
public String accountId() {
return accountId;
}
/**
* Forces static initialization of weblogic.jdbc.jts.Driver
*
*/
static {
new weblogic.jdbc.jts.Driver(); // force static initialization
}
/**
* Returns the name of the table used for generating IDs
*
* @return String Name of table for generating IDs
*/
private String getIdTableName() {
return (String) props.get("idTable");
}
/**
* Returns the number of unique ids to be allocated each time
*
* @return int Range of ids
*/
private int getRange() {
return new Integer((String) props.get("creationRange")).intValue();
}
/**
* Returns value of a property listed in the "jdbc" property of the
* "persistentStoreProperties" entry of the deployment descriptor.
*
* @param propertyName String Name of property to retrieve
* @return String Property value
*/
private String getJdbcProperty(String propertyName) {
Hashtable ht;
ht = (Hashtable)props.get("persistentStoreProperties");
if (ht != null) {
String psType = (String)ht.get("persistentStoreType");
if (psType != null && psType.equalsIgnoreCase("jdbc")) {
ht = (Hashtable)ht.get(psType);
if (ht != null)
return (String)ht.get(propertyName);
}
}
return null;
}
/**
* Returns a connection from the database pool defined in the
* deployment descriptor for the bean.
*
* @return Connection Database connection
* if there is an error getting a Connection
*/
private Connection getConnection() throws SQLException {
return DriverManager.getConnection("jdbc:weblogic:jts:" + getJdbcProperty("poolName"));
}
}