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com.jcorporate.expresso.services.dbobj
Class MediaDBObject  

java.lang.Object
  com.jcorporate.expresso.core.dataobjects.BaseDataObject
      com.jcorporate.expresso.core.dataobjects.jdbc.JDBCDataObject
          com.jcorporate.expresso.core.dbobj.DBObject
              com.jcorporate.expresso.core.dbobj.SecuredDBObject
                  com.jcorporate.expresso.services.dbobj.MediaDBObject

All Implemented Interfaces:

com.jcorporate.expresso.core.cache.Cacheable, com.jcorporate.expresso.core.dataobjects.ContextNested, com.jcorporate.expresso.core.dataobjects.DataObject, com.jcorporate.expresso.core.dbobj.LookupInterface, com.jcorporate.expresso.core.dataobjects.Securable, java.io.Serializable

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public class MediaDBObject

extends com.jcorporate.expresso.core.dbobj.SecuredDBObject

A MediaDBObject is a DBObject intended to be used for storage of media objects directly in the database. It facilitates generic storage by automatically creating filename and MimeType fields that map to the MimeTypes table for easy downloading. This allows for the ability to store more than one media type in the same table while still allowing the Application to appropriately deal with each MimeType.

This data object conveniently stores and retrieves Binary Large OBjects (BLOBS) or Character Large OBjects (CLOBS).

Performance note: Each blob field access requires one more round trip to the database since BLOBs cannot be effectively stored in memory. Thus the lazy loading.

Typical Usage:

 myMediaDBObject = new myMediaDBObject();
 File f = new File("/temp/output.tmp");
 FileOutputStream fos = new FileOutputStream(f);
 myMediaDBObject.setField("id", 2)
 InputStream is = myMediaDBObject.retrieveBlob("picture");
 // Copy the input stream to the file output stream
 myMediaDBObject.release();
 

Since:

Expresso 5.1

Version:

$Revision: 1.9 $ on $Date: 2004/11/17 20:48:18 $

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Nested Class Summary

 

Nested classes inherited from class com.jcorporate.expresso.core.dbobj.DBObject

com.jcorporate.expresso.core.dbobj.DBObject.FieldError, com.jcorporate.expresso.core.dbobj.DBObject.FieldUpdate

 

Field Summary
static java.lang.String	FLD_FILE_SUFFIX           Suffix for the filename field.
static java.lang.String	FLD_MIME_SUFFIX           Suffix for the mime number field.
static java.lang.String	FLD_SIZE_SUFFIX           Suffix for the file size field.
private  com.jcorporate.expresso.core.dataobjects.jdbc.LobField	lf           The LOBField object for streaming data into and out of the Database
private static org.apache.log4j.Logger	log           The Log4j Logger

 

Fields inherited from class com.jcorporate.expresso.core.dbobj.SecuredDBObject

ADD, ALL_FUNCTIONS, CACHE_NAME, CACHE_TTY, DELETE, SEARCH, SYSTEM_ACCOUNT, SYSTEM_ACCOUNT_NAME, UPDATE

 

Fields inherited from class com.jcorporate.expresso.core.dbobj.DBObject

ATTRIBUTE_ERROR, ATTRIBUTE_ERROR_MESSAGE, ATTRIBUTE_PAGE_LIMIT, BIG_DECIMAL_ZERO, EMAIL_MASK, EVENT_ADD, EVENT_DELETE, EVENT_UPDATE, FLOAT_MASK, INT_MASK, IS_CHECK_RELATIONAL_INTEGRITY, UPDATE_CHANGED_ONLY, WHERE_KEYWORD

 

Fields inherited from class com.jcorporate.expresso.core.dataobjects.jdbc.JDBCDataObject

anyFieldsDistinct, anyFieldsToRetrieve, appendCustomWhere, caseSensitiveQuery, customWhereClause, dbKey, distinctFields, localConnection, LONGBINARY_READ_DEFAULT_SIZE, maxRecords, myClassName, myUpdates, offsetRecord, recordSet, retrieveFields, sMetadataMap, sortKeys

 

Fields inherited from class com.jcorporate.expresso.core.dataobjects.BaseDataObject

currentStatus, globalMask

 

Fields inherited from interface com.jcorporate.expresso.core.dataobjects.DataObject

STATUS_CURRENT, STATUS_DELETED, STATUS_NEW, STATUS_UPDATED

 

Constructor Summary

MediaDBObject()           Default Constructor.

MediaDBObject(com.jcorporate.expresso.core.db.DBConnection newConnection)           Constructor that sets the connection on create

MediaDBObject(com.jcorporate.expresso.core.db.DBConnection newConnection, java.lang.String setupTablesContext)            Constructor that sets a connection as the object is created - typically this is used when a particular DBConnection is required for the purposes of maintaining a database transaction.

MediaDBObject(int newUid)           Constructor: Specify a DB connection AND user

MediaDBObject(com.jcorporate.expresso.core.dbobj.RequestContext request)           For using DBObjects within Controllers.

 

Method Summary
protected  void	addBlobField(java.lang.String fieldName, java.lang.String fieldDescription)           Adds a BLOB field definition to this DBObject.
java.lang.String	getBlobFilename(java.lang.String fieldName)           Convenience method to get the LOB attachment filename
java.lang.String	getBlobFileSize(java.lang.String fieldName)           Convenience method to get the LOB attachment content length
int	getBlobFileSizeInt(java.lang.String fieldName)           Convenience method to get the LOB attachment content length as an integer
java.lang.String	getBlobMimeType(java.lang.String fieldName)           Convenience method to get the LOB attachment mime content type
void	release()           Release the associated data with the blob fields.
java.io.InputStream	retrieveBlob(java.lang.String fieldName)           Retrieves a BLOB from the database.
void	saveBlob(java.lang.String fieldName)           This method is for saving a BLOB field that has been processed by the DefaultAutoElement object.
void	saveBlob(java.lang.String fieldName, java.io.InputStream value, int fileSize)           Saves a file to the blob field,
void	saveBlob(java.lang.String fieldName, java.io.InputStream value, java.lang.String fileName, int fileSize)           Saves a BLOB field to the database

 

Methods inherited from class com.jcorporate.expresso.core.dbobj.SecuredDBObject

add, canRequesterAdd, canRequesterDelete, canRequesterRead, canRequesterUpdate, checkAllowed, copyAttributes, count, createSecurityCache, delete, deleteAll, find, getRequestingUid, getString, getString, getString, getString, getString, getString, getSystemUid, instantiate, isAllowed, retrieve, search, searchAndRetrieveList, searchAndRetrieveList, setRequestingUid, update

 

Methods inherited from class com.jcorporate.expresso.core.dbobj.DBObject

addDetail, addField, addField, addFieldError, addFoundKeys, addIfNeeded, addIndex, addKey, addOrUpdate, addSortKey, addTransition, addVirtualField, addVirtualField, addVirtualField, addVirtualField, average, basicAdd, cacheIsChangedComparison, checkAllReferredToBy, checkAllRefs, checkAllRefsPublic, checkDeleteDetailPerm, checkField, checkRef, checkRef, clear, clearDistinctFields, clearError, clearFieldsToRetrieve, clearSortKeys, containsWildCards, delete, deleteAll, deleteDetails, denotesRange, equals, forKey, formatDateTime, get, getAllAttributes, getAttribute, getAttributesIterator, getBooleanFieldValue, getCacheSize, getCacheStatsMap, getCacheUtil, getCheckZeroUpdate, getCustomWhereClause, getDataContext, getDataField, getDataTransferObject, getDBName, getDetails, getDistinctFieldCount, getDistinctFields, getField, getFieldBigDecimal, getFieldBoolean, getFieldByte, getFieldByteArray, getFieldData, getFieldDate, getFieldDecimalFormatted, getFieldDouble, getFieldErrorMessage, getFieldFloat, getFieldInt, getFieldLong, getFieldMetaData, getFieldShort, getFieldsToRetrieveCount, getFilterClass, getFoundCount, getFoundKeysArray, getIndexArray, getISOValuesDefault, getISOValuesDefault, getISOValuesDefault, getKey, getKeyFieldListIterator, getLength, getLengthInt, getLocalConnection, getLocale, getLogger, getLookupObject, getMax, getMax, getMaxRecords, getMyKeys, getMyUpdatesArray, getOffsetRecord, getPatternMatcher, getPrecision, getSerializedForm, getStringFilter, getThisDBbj, getThisDBObj, getValidValueDescrip, getValidValues, getValidValuesList, getValues, getValuesDefault, getValuesDefault, getValuesDefault, hasError, hasErrors, haveAllKeys, initialize, isCached, isChanged, isDistinct, isEmpty, isFieldDistinct, isFieldNull, isFieldsToRetrieve, isFieldToRetrieve, isMultiValued, isReadOnly, isSecret, isVirtual, loadFromConnection, logChange, max, min, newInstance, noNewLine, noQuotes, notifyListeners, populateDefaultValues, referredToBy, removeAttribute, removeFromCache, retrieveFromCache, saveBinaryField, search, set, setAttribute, setCacheSize, setCharset, setCheckZeroUpdate, setConnection, setConnection, setCustomWhereClause, setCustomWhereClause, setDataContext, setDataField, setDataTransferObject, setDefaultValue, setDescription, setField, setField, setField, setField, setField, setField, setField, setField, setField, setField, setFieldData, setFieldData, setFieldDistinct, setFieldsToRetrieve, setFilterClass, setFilterClass, setKeys, setLocale, setLookupField, setLookupObject, setMask, setMaxRecords, setMultiValued, setName, setOffsetRecord, setReadOnly, setSchema, setSecret, setSortKey, setStringFilter, setStringFiltersOnAll, setTargetDbSchema, setTargetTable, setupFields, sqlAggrFunction, sum, toDebugString, update, updateAll, updateAll, verify

 

Methods inherited from class com.jcorporate.expresso.core.dataobjects.jdbc.JDBCDataObject

addInParam, addOutParam, buildWhereClause, buildWhereClauseBuffer, checkZeroUpdate, constructNewMetaData, createAndExecuteSearch, createAndRunStoreProcedure, getConnectionPool, getCustomStringFieldValue, getDef, getDistinctFieldArrayList, getExecutor, getFieldsToRetrieveIterator, getJDBCMetaData, getJDBCUtil, getMappedDataContext, getMetaData, getQueryInterface, getSerialForm, loadFromConnection, makeLimitationStub, quoteIfNeeded, runStoredProcedure, runStoredProcedureAndRetrieveList, selectFieldString, setCaseSensitiveQuery, setDBConnectionPool, setDBName, setMappedDataContext, setOriginalDBName, setTargetStoreProcedure

 

Methods inherited from class com.jcorporate.expresso.core.dataobjects.BaseDataObject

getGlobalMask, getStatus, isGlobalMasked, setFieldsWithDefaults, setGlobalMask, setStatus

 

Methods inherited from class java.lang.Object

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

 

Field Detail

lf

private com.jcorporate.expresso.core.dataobjects.jdbc.LobField lf

The LOBField object for streaming data into and out of the Database

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log

private static final org.apache.log4j.Logger log

The Log4j Logger

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FLD_FILE_SUFFIX

public static final java.lang.String FLD_FILE_SUFFIX

Suffix for the filename field.

Each blob field has several additional supporting fields. The supporting fields have the name of the original BLOB field plus a suffix that is appended to the BLOB field name to get the supporting field

See Also:

Constant Field Values

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FLD_MIME_SUFFIX

public static final java.lang.String FLD_MIME_SUFFIX

Suffix for the mime number field. This field contains a pointer into the MimeTypes table.

Each blob field has several additional supporting fields. The supporting fields have the name of the original BLOB field plus a suffix that is appended to the BLOB field name to get the supporting field

See Also:

Constant Field Values

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FLD_SIZE_SUFFIX

public static final java.lang.String FLD_SIZE_SUFFIX

Suffix for the file size field. This field contains the size of the blob that was saved to the database.

Each blob field has several additional supporting fields. The supporting fields have the name of the original BLOB field plus a suffix that is appended to the BLOB field name to get the supporting field

See Also:

Constant Field Values

Constructor Detail

MediaDBObject

public MediaDBObject()
              throws com.jcorporate.expresso.core.db.DBException

Default Constructor.

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MediaDBObject

public MediaDBObject(com.jcorporate.expresso.core.db.DBConnection newConnection)
              throws com.jcorporate.expresso.core.db.DBException

Constructor that sets the connection on create

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MediaDBObject

public MediaDBObject(com.jcorporate.expresso.core.db.DBConnection newConnection,
                     java.lang.String setupTablesContext)
              throws com.jcorporate.expresso.core.db.DBException

Constructor that sets a connection as the object is created - typically this is used when a particular DBConnection is required for the purposes of maintaining a database transaction. If a specific connection is not used, there is no way to use commit() and rollback() in the event of failure, as a different DBConnection might be used for each phase of the transaction. Critial sections should therefore explicity request a DBConnection from the connection pool and pass it to each of the DB objects in that section.

This constructor is neceesary to work with otherDBMap and transaction capabilities

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MediaDBObject

public MediaDBObject(int newUid)
              throws com.jcorporate.expresso.core.db.DBException

Constructor: Specify a DB connection AND user

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MediaDBObject

public MediaDBObject(com.jcorporate.expresso.core.dbobj.RequestContext request)
              throws com.jcorporate.expresso.core.db.DBException

For using DBObjects within Controllers. Initializes based upon the current user and the requested db. [Of course this can be modified later]

Method Detail

getBlobFilename

public java.lang.String getBlobFilename(java.lang.String fieldName)
                                 throws com.jcorporate.expresso.core.db.DBException

Convenience method to get the LOB attachment filename

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getBlobMimeType

public java.lang.String getBlobMimeType(java.lang.String fieldName)
                                 throws com.jcorporate.expresso.core.db.DBException

Convenience method to get the LOB attachment mime content type

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getBlobFileSize

public java.lang.String getBlobFileSize(java.lang.String fieldName)
                                 throws com.jcorporate.expresso.core.db.DBException

Convenience method to get the LOB attachment content length

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getBlobFileSizeInt

public int getBlobFileSizeInt(java.lang.String fieldName)
                       throws com.jcorporate.expresso.core.db.DBException

Convenience method to get the LOB attachment content length as an integer

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addBlobField

protected void addBlobField(java.lang.String fieldName,
                            java.lang.String fieldDescription)
                     throws com.jcorporate.expresso.core.db.DBException

Adds a BLOB field definition to this DBObject.

Using this method creates several supporting fields.

• BlobFieldName + '_mimeType': An integer value that points to the mime type in the MimeTypes table. When the BLOB is retrieved, the content stream mime type can be set allowing for the web browser to properly interpret the incoming stream.
• BlobFieldName + '_fileName': A file name for the BLOB field. While this is optional, it allows the WebBrowser to assign a default file name when it saves the BLOB locally
• BlobFieldName + '_fileSize': This field gets set when a file is uploaded into the database table. It allows for the browser to determine what percentage of the BLOB is transferred to the browser

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saveBlob

public void saveBlob(java.lang.String fieldName)
              throws com.jcorporate.expresso.core.db.DBException

This method is for saving a BLOB field that has been processed by the DefaultAutoElement object. We have all the information we need because the file to save, mime types, etc, have all been saved as attributes of the fieldName specified. Do not call this method if you have not either set the appropriate attributes yourself or have called DefaultAutoElement.parseSingleInput().

This method also deletes the uploaded temp file upon completion. Create the File object and call one of the other saveBlob objects yourself if you do not want this behavior.

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saveBlob

public void saveBlob(java.lang.String fieldName,
                     java.io.InputStream value,
                     java.lang.String fileName,
                     int fileSize)
              throws com.jcorporate.expresso.core.db.DBException

Saves a BLOB field to the database

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saveBlob

public void saveBlob(java.lang.String fieldName,
                     java.io.InputStream value,
                     int fileSize)
              throws com.jcorporate.expresso.core.db.DBException

Saves a file to the blob field,

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retrieveBlob

public java.io.InputStream retrieveBlob(java.lang.String fieldName)
                                 throws com.jcorporate.expresso.core.db.DBException

Retrieves a BLOB from the database. This functiona allocates a DBConnection object and all the corresponding input streams. You must process the BLOB before doing anything else to this particular DBObject, and then call the release() function to release the DBConnection and close the appropriate InputStreams.

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release

public void release()

Release the associated data with the blob fields. Very important that this is called once you've retrieved/set the BLOB fields.

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Overview  Package   Class  Use  Deprecated  Index
Home >> All >> com >> jcorporate >> expresso >> services >> [ dbobj overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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