to.etc.webapp.qsql

Class JdbcDataContext

java.lang.Object

to.etc.webapp.qsql.JdbcDataContext

All Implemented Interfaces:

AutoCloseable, QDataContext

public class JdbcDataContext
extends Object
implements QDataContext

WATCH OUT- THIS DOES NOT OBEY OBJECT IDENTITY RULES!! Records loaded through this code are NOT mapped by identity, so multiple queries for the same object WILL return different copies!!

This is a poor-man's datacontext that can be used to do JDBC queries using the QCriteria interface.

Author:

Frits Jalvingh Created on Mar 10, 2010

Constructor Summary

Constructors

Constructor and Description
JdbcDataContext(QDataContextFactory factory, Connection dbc)

Method Summary

Modifier and Type	Method and Description
void	addCommitAction(IRunnable cx) Add an action which should be executed after a succesful commit on this context.
void	addListener(IQDataContextListener qDataContextListener) Add a listener to keep track of the events on an instance.
void	attach(Object o) DOES NOTHING.
void	close() This will close and fully discard all resources belonging to this context, provided ignoreClose is not true.
void	commit()
void	delete(Object o) Unsupported for JDBC code.
<T> T	find(Class<T> clz, Object pk) Locate the specified record by PK.
<T> T	find(ICriteriaTableDef<T> metatable, Object pk)
<T> T	get(Class<T> clz, Object pk) Load the persistent object with the specified type and primary key from the database.
Connection	getConnection() Return the underlying connection verbatim.
QDataContextFactory	getFactory() Returns the context source which created this DataContext.
<T> T	getInstance(Class<T> clz, Object pk) Get an instance; this will return an instance by first trying to load it; if that fails it will create one but only fill the PK.
<T> T	getInstance(ICriteriaTableDef<T> clz, Object pk)
protected Connection	internalGetConnection()
protected void	internalSetConnection(Connection dbc)
boolean	inTransaction()
<T> T	original(T copy) EXPERIMENTAL INTERFACE This retrieves the "original" copy of the specified instance (which must be loaded inside this data context).
<R> List<R>	query(Class<R> resultInterface, QSelection<?> sel) Query a selection, and return the result in the specified proxied interface.
<T> List<T>	query(QCriteria<T> q) Execute the query specified by q and return a list of results.
List<Object[]>	query(QSelection<?> sel) Issue a selection query, where multiple fields or projections on fields are selected from a base class.
<R> R	queryOne(Class<R> resultInterface, QSelection<?> sel) Query a selection, and return the result in the specified proxied interface.
<T> T	queryOne(QCriteria<T> q) Execute the query specified by q, and expect and return at most 1 result.
Object[]	queryOne(QSelection<?> q) Execute the selection query specified by q, and expect and return at most 1 result.
void	refresh(Object o) Not suppore
void	rollback()
void	save(Object o) Not supported
void	setIgnoreClose(boolean on) When ignoreClose is set to T the close call must be silently ignored.
void	setKeepOriginals() EXPERIMENTAL Sets the context so that it creates "before" copies.
void	startTransaction()
protected void	unclosed()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JdbcDataContext

public JdbcDataContext(QDataContextFactory factory,
                       Connection dbc)

Method Detail

internalSetConnection

protected void internalSetConnection(Connection dbc)

internalGetConnection

protected Connection internalGetConnection()
                                    throws Exception

Throws:

Exception

unclosed

protected void unclosed()
                 throws Exception

Throws:

Exception

attach

public void attach(@Nonnull
                   Object o)
            throws Exception

DOES NOTHING.

Specified by:

attach in interface QDataContext

Throws:

Exception

See Also:

QDataContext.attach(java.lang.Object)

close

public void close()

Description copied from interface: QDataContext

This will close and fully discard all resources belonging to this context, provided ignoreClose is not true. A closed context cannot be reused anymore and should be discarded.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface QDataContext

commit

public void commit()
            throws Exception

Specified by:

commit in interface QDataContext

Throws:

Exception

delete

public void delete(@Nonnull
                   Object o)
            throws Exception

Unsupported for JDBC code.

Specified by:

delete in interface QDataContext

Throws:

Exception

See Also:

QDataContext.delete(java.lang.Object)

find

public <T> T find(@Nonnull
                  Class<T> clz,
                  @Nonnull
                  Object pk)
           throws Exception

Locate the specified record by PK.

Specified by:

find in interface QDataContext

Type Parameters:

T - The object type.

Parameters:

clz - The persistent class for which an instance is being sought.

pk - The PK for the instance required.

Returns:

Null if the instance does not exist, the actual and fully initialized instance (or proxy) otherwise.

Throws:

Exception

See Also:

QDataContext.find(java.lang.Class, java.lang.Object)

get

@Nonnull
public <T> T get(@Nonnull
                          Class<T> clz,
                          @Nonnull
                          Object pk)
                   throws Exception

Load the persistent object with the specified type and primary key from the database. This will execute an actual select in the database if the object is not yet cached, ensuring that the object actually exists. If the object does not exist this will raise QNotFoundException.

Specified by:

get in interface QDataContext

Type Parameters:

T - The object type.

Parameters:

clz - The persistent class for which an instance is being sought.

pk - The PK for the instance required.

Returns:

The actual and fully initialized instance (or proxy).

Throws:

Exception

See Also:

QDataContext.get(java.lang.Class, java.lang.Object)

getInstance

@Nonnull
public <T> T getInstance(@Nonnull
                                  Class<T> clz,
                                  @Nonnull
                                  Object pk)
                           throws Exception

Get an instance; this will return an instance by first trying to load it; if that fails it will create one but only fill the PK. Use is questionable though.

Specified by:

getInstance in interface QDataContext

Type Parameters:

T - The object type

Parameters:

clz - The persistent class for which an instance is being sought.

pk - The PK for the instance required.

Returns:

Always returns an instance; it can be invalid when it does not really exist on the backing store.

Throws:

Exception

See Also:

QDataContext.getInstance(java.lang.Class, java.lang.Object)

getConnection

@Nonnull
public Connection getConnection()
                                  throws Exception

Return the underlying connection verbatim.

Specified by:

getConnection in interface QDataContext

Throws:

Exception

See Also:

QDataContext.getConnection()

getFactory

@Nonnull
public QDataContextFactory getFactory()

Description copied from interface: QDataContext

Returns the context source which created this DataContext. This context source is used to get query listeners to execute when a query is done.

Specified by:

getFactory in interface QDataContext

Returns:

inTransaction

public boolean inTransaction()
                      throws Exception

Specified by:

inTransaction in interface QDataContext

Throws:

Exception

query

@Nonnull
public <T> List<T> query(@Nonnull
                                  QCriteria<T> q)
                           throws Exception

Description copied from interface: QDataContext

Execute the query specified by q and return a list of results. Before and after the query execution all registered listeners will be called.

Specified by:

query in interface QDataContext

Type Parameters:

T - The return type for this query, a persistent class type

Parameters:

q - The selection criteria

Returns:

Throws:

Exception

query

@Nonnull
public List<Object[]> query(@Nonnull
                                     QSelection<?> sel)
                              throws Exception

Description copied from interface: QDataContext

Issue a selection query, where multiple fields or projections on fields are selected from a base class.

Specified by:

query in interface QDataContext

Returns:

Throws:

Exception

queryOne

public <T> T queryOne(@Nonnull
                      QCriteria<T> q)
               throws Exception

Description copied from interface: QDataContext

Execute the query specified by q, and expect and return at most 1 result. If the query has no result this will return null. If more than one result is obtained this will throw an IllegalStateException.

Specified by:

queryOne in interface QDataContext

Returns:

Throws:

Exception

queryOne

public Object[] queryOne(@Nonnull
                         QSelection<?> q)
                  throws Exception

Description copied from interface: QDataContext

Execute the selection query specified by q, and expect and return at most 1 result. If the query has no result this will return null. If more than one result is obtained this will throw an IllegalStateException.

Specified by:

queryOne in interface QDataContext

Returns:

Throws:

Exception

find

public <T> T find(@Nonnull
                  ICriteriaTableDef<T> metatable,
                  @Nonnull
                  Object pk)
           throws Exception

Specified by:

find in interface QDataContext

Throws:

Exception

query

@Nonnull
public <R> List<R> query(@Nonnull
                                  Class<R> resultInterface,
                                  @Nonnull
                                  QSelection<?> sel)
                           throws Exception

Description copied from interface: QDataContext

Query a selection, and return the result in the specified proxied interface. Members in the interface must be annotated with QFld annotations to define the order in the result set.

Specified by:

query in interface QDataContext

Returns:

Throws:

Exception

queryOne

@Nullable
public <R> R queryOne(@Nonnull
                                Class<R> resultInterface,
                                @Nonnull
                                QSelection<?> sel)
                         throws Exception

Description copied from interface: QDataContext

Query a selection, and return the result in the specified proxied interface. Members in the interface must be annotated with QFld annotations to define the order in the result set.

Specified by:

queryOne in interface QDataContext

Returns:

Throws:

Exception

getInstance

@Nonnull
public <T> T getInstance(@Nonnull
                                  ICriteriaTableDef<T> clz,
                                  @Nonnull
                                  Object pk)
                           throws Exception

Specified by:

getInstance in interface QDataContext

Throws:

Exception

refresh

public void refresh(@Nonnull
                    Object o)
             throws Exception

Not suppore

Specified by:

refresh in interface QDataContext

Throws:

Exception

See Also:

QDataContext.refresh(java.lang.Object)

rollback

public void rollback()
              throws Exception

Specified by:

rollback in interface QDataContext

Throws:

Exception

save

public void save(@Nonnull
                 Object o)
          throws Exception

Not supported

Specified by:

save in interface QDataContext

Throws:

Exception

See Also:

QDataContext.save(java.lang.Object)

setIgnoreClose

public void setIgnoreClose(boolean on)

Description copied from interface: QDataContext

When ignoreClose is set to T the close call must be silently ignored. Ugly, but for a lot of reasons (all having to do with the very strained object model around the ViewPoint database code) this is the least invasive method to allow for per-conversation shared contexts. Please do not replace this with any kind of wrapper/proxy based solution; it will not work.

Specified by:

setIgnoreClose in interface QDataContext

startTransaction

public void startTransaction()
                      throws Exception

Specified by:

startTransaction in interface QDataContext

Throws:

Exception

addCommitAction

public void addCommitAction(@Nonnull
                            IRunnable cx)

Description copied from interface: QDataContext

Add an action which should be executed after a succesful commit on this context.

Specified by:

addCommitAction in interface QDataContext

addListener

public void addListener(@Nonnull
                        IQDataContextListener qDataContextListener)

Add a listener to keep track of the events on an instance.

Specified by:

addListener in interface QDataContext

See Also:

QDataContext.addListener(to.etc.webapp.query.IQDataContextListener)

original

public <T> T original(@Nonnull
                      T copy)

Description copied from interface: QDataContext

EXPERIMENTAL INTERFACE This retrieves the "original" copy of the specified instance (which must be loaded inside this data context). The original copy contains the field instances as they were before the record was loaded.

Specified by:

original in interface QDataContext

Returns:

setKeepOriginals

public void setKeepOriginals()

Description copied from interface: QDataContext

EXPERIMENTAL Sets the context so that it creates "before" copies. Can only be used before any data is loaded. If the context does not support before copies this throws Exception.

Specified by:

setKeepOriginals in interface QDataContext