com.uwyn.rife.resources
Class DatabaseResources

java.lang.Object
  com.uwyn.rife.database.DbQueryManager
      com.uwyn.rife.resources.DatabaseResources

All Implemented Interfaces:

ResourceFinder, ResourceWriter, Cloneable

public abstract class DatabaseResources
extends DbQueryManager
implements ResourceFinder, ResourceWriter

This class offers ResourceFinder and ResourceWriter capabilities for resources that are stored in a database. The relevant database is specified through a Datasource/code> instance at construction.

While the table can be configured through the TABLE_RESOURCES configuration setting, the structure of the table is fixed. It can be installed with the install() method and removed with the remove() method. The latter will implicitely erase all the resources that have been stored in the database table.

Since:

1.0

Version:

$Revision: 3634 $

Author:

Geert Bevin (gbevin[remove] at uwyn dot com)

See Also:

ResourceFinder

Field Summary

protected static String	COLUMN_CONTENT
protected static String	COLUMN_MODIFIED
protected static String	COLUMN_NAME
protected static String	PROTOCOL

Constructor Summary

protected

DatabaseResources(Datasource datasource) Creates a new instance according to the provided datasource.

Method Summary

protected void	_addResource(Insert addResource, String name, String content)
protected String	_getContent(Select getResourceContent, URL resource, String encoding)
protected long	_getModificationTime(Select getResourceModified, URL resource)
protected URL	_getResource(Select hasResource, String name)
protected boolean	_install(CreateTable createTable)
protected boolean	_remove(DropTable dropTable)
protected boolean	_removeResource(Delete removeResource, String name)
protected boolean	_updateResource(Update updateResource, String name, String content)
protected <ResultType> ResultType	_useStream(Select getResourceContent, URL resource, InputStreamUser user)
String	getContent(String name) Retrieves the complete content of the resource that corresponds to the provided name.
String	getContent(String name, String encoding) Retrieves the complete content of the resource that corresponds to the provided name.
String	getContent(URL resource) Retrieves the complete content of the provided resource.
long	getModificationTime(String name) Retrieves the modification time of the resource that corresponds to the provided name.
abstract boolean	install() Installs the database structure that's needed to store and retrieve resources in and from a database.
abstract boolean	remove() Removes the database structure that's needed to store and retrieve resources in and from a database.
<ResultType> ResultType	useStream(String name, InputStreamUser user) Returns a stream that can be used to read the contents of the resource that corresponds to the provided name.

Methods inherited from class com.uwyn.rife.database.DbQueryManager

clone, executeFetchAll, executeFetchAll, executeFetchAllBeans, executeFetchAllBeans, executeFetchFirst, executeFetchFirst, executeFetchFirstBean, executeFetchFirstBean, executeGetFirstBoolean, executeGetFirstBoolean, executeGetFirstByte, executeGetFirstByte, executeGetFirstBytes, executeGetFirstBytes, executeGetFirstDate, executeGetFirstDate, executeGetFirstDate, executeGetFirstDate, executeGetFirstDouble, executeGetFirstDouble, executeGetFirstFloat, executeGetFirstFloat, executeGetFirstInt, executeGetFirstInt, executeGetFirstLong, executeGetFirstLong, executeGetFirstShort, executeGetFirstShort, executeGetFirstString, executeGetFirstString, executeGetFirstTime, executeGetFirstTime, executeGetFirstTime, executeGetFirstTime, executeGetFirstTimestamp, executeGetFirstTimestamp, executeGetFirstTimestamp, executeGetFirstTimestamp, executeHasResultRows, executeHasResultRows, executeQuery, executeQuery, executeQuery, executeUpdate, executeUpdate, executeUpdate, executeUseFirstAsciiStream, executeUseFirstAsciiStream, executeUseFirstBinaryStream, executeUseFirstBinaryStream, executeUseFirstCharacterStream, executeUseFirstCharacterStream, fetch, fetch, fetchAll, getConnection, getDatasource, inTransaction, reserveConnection

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.uwyn.rife.resources.ResourceFinder

getContent, getModificationTime, getResource, useStream

Methods inherited from interface com.uwyn.rife.resources.ResourceWriter

addResource, removeResource, updateResource

Field Detail

PROTOCOL

protected static final String PROTOCOL

See Also:

Constant Field Values

COLUMN_NAME

protected static final String COLUMN_NAME

See Also:

Constant Field Values

COLUMN_CONTENT

protected static final String COLUMN_CONTENT

See Also:

Constant Field Values

COLUMN_MODIFIED

protected static final String COLUMN_MODIFIED

See Also:

Constant Field Values

Constructor Detail

DatabaseResources

protected DatabaseResources(Datasource datasource)

Creates a new instance according to the provided datasource.

Parameters:

datasource - the Datasource instance that defines the database that will be used as resources storage.

Since:

1.0

Method Detail

install

public abstract boolean install()
                         throws ResourceWriterErrorException

Installs the database structure that's needed to store and retrieve resources in and from a database.

Throws:

ResourceFinderErrorException - when an error occurred during the installation

ResourceWriterErrorException

remove

public abstract boolean remove()
                        throws ResourceWriterErrorException

Removes the database structure that's needed to store and retrieve resources in and from a database.

Throws:

ResourceFinderErrorException - when an error occurred during the removal

ResourceWriterErrorException

_install

protected boolean _install(CreateTable createTable)
                    throws ResourceWriterErrorException

Throws:

ResourceWriterErrorException

_remove

protected boolean _remove(DropTable dropTable)
                   throws ResourceWriterErrorException

Throws:

ResourceWriterErrorException

_addResource

protected void _addResource(Insert addResource,
                            String name,
                            String content)
                     throws ResourceWriterErrorException

Throws:

ResourceWriterErrorException

_updateResource

protected boolean _updateResource(Update updateResource,
                                  String name,
                                  String content)
                           throws ResourceWriterErrorException

Throws:

ResourceWriterErrorException

_removeResource

protected boolean _removeResource(Delete removeResource,
                                  String name)
                           throws ResourceWriterErrorException

Throws:

ResourceWriterErrorException

_getResource

protected URL _getResource(Select hasResource,
                           String name)

_useStream

protected <ResultType> ResultType _useStream(Select getResourceContent,
                                             URL resource,
                                             InputStreamUser user)
                         throws ResourceFinderErrorException,
                                InnerClassException

Throws:

ResourceFinderErrorException

InnerClassException

_getContent

protected String _getContent(Select getResourceContent,
                             URL resource,
                             String encoding)
                      throws ResourceFinderErrorException

Throws:

ResourceFinderErrorException

_getModificationTime

protected long _getModificationTime(Select getResourceModified,
                                    URL resource)

useStream

public <ResultType> ResultType useStream(String name,
                                         InputStreamUser user)
                     throws ResourceFinderErrorException,
                            InnerClassException

Description copied from interface: ResourceFinder

Returns a stream that can be used to read the contents of the resource that corresponds to the provided name.

Specified by:

useStream in interface ResourceFinder

Parameters:

name - the name of the resource to retrieve

user - an instance of InputStreamUser that contains the logic that will be executed with this stream

Returns:

the return value from the useInputStream method of the provided InputStreamUser instance

Throws:

ResourceFinderErrorException - when an error occurred during the creation or opening of the stream.

InnerClassException - when errors occurs inside the InputStreamUser

See Also:

InputStreamUser, ResourceFinder.useStream(URL, InputStreamUser)

getContent

public String getContent(String name)
                  throws ResourceFinderErrorException

Description copied from interface: ResourceFinder

Retrieves the complete content of the resource that corresponds to the provided name. The content will be read into a string by using the platform's default encoding.

Specified by:

getContent in interface ResourceFinder

Parameters:

name - the name of the resource to retrieve

Returns:

a String object that contains the complete content of the resource with the provided name; or

null if the resource couldn't be found.

Throws:

ResourceFinderErrorException - when an error occurred during the retrieval of the content.

See Also:

ResourceFinder.getContent(String, String), ResourceFinder.getContent(URL, String)

getContent

public String getContent(String name,
                         String encoding)
                  throws ResourceFinderErrorException

Description copied from interface: ResourceFinder

Retrieves the complete content of the resource that corresponds to the provided name.

Specified by:

getContent in interface ResourceFinder

Parameters:

name - the name of the resource to retrieve the content from

encoding - the encoding that should be used to read the content

Returns:

a String object that contains the complete content of the resource with the provided name; or

null if the resource couldn't be found.

Throws:

ResourceFinderErrorException - when an error occurred during the retrieval of the content or when the encoding is not supported.

See Also:

ResourceFinder.getContent(String), ResourceFinder.getContent(URL), ResourceFinder.getContent(URL, String)

getContent

public String getContent(URL resource)
                  throws ResourceFinderErrorException

Description copied from interface: ResourceFinder

Retrieves the complete content of the provided resource. The content will be read into a string by using the platform's default encoding.

Specified by:

getContent in interface ResourceFinder

Parameters:

resource - the resource to retrieve the content from

Returns:

a String object that contains the complete content of the resource with the provided name; or

null if the resource couldn't be found.

Throws:

ResourceFinderErrorException - when an error occurred during the retrieval of the content or when the encoding is not supported.

See Also:

ResourceFinder.getContent(String), ResourceFinder.getContent(String, String), ResourceFinder.getContent(URL, String)

getModificationTime

public long getModificationTime(String name)
                         throws ResourceFinderErrorException

Description copied from interface: ResourceFinder

Retrieves the modification time of the resource that corresponds to the provided name.

Specified by:

getModificationTime in interface ResourceFinder

Parameters:

name - the name of the resource to retrieve

Returns:

a positive long with the modification time in milliseconds; or

-1 if the resource couldn't be found.

Throws:

ResourceFinderErrorException - when an error occurred during the retrieval of the modification time.

See Also:

ResourceFinder.getModificationTime(URL)