org.apache.jackrabbit.core.journal
Class DatabaseJournal

java.lang.Object
  org.apache.jackrabbit.core.journal.AbstractJournal
      org.apache.jackrabbit.core.journal.DatabaseJournal

All Implemented Interfaces:

Journal

Direct Known Subclasses:

JNDIDatabaseJournal, MSSqlDatabaseJournal, OracleDatabaseJournal

public class DatabaseJournal
extends AbstractJournal

Database-based journal implementation. Stores records inside a database table named JOURNAL, whereas the table GLOBAL_REVISION contains the highest available revision number. These tables are located inside the schema specified in schemaObjectPrefix.

It is configured through the following properties:

• revision: the filename where the parent cluster node's revision file should be written to; this is a required property with no default value
• driver: the JDBC driver class name to use; this is a required property with no default value
• url: the JDBC connection url; this is a required property with no default value
• schema: the schema to be used; if not specified, this is the second field inside the JDBC connection url, delimeted by colons
• schemaObjectPrefix: the schema object prefix to be used; defaults to an empty string
• user: username to specify when connecting
• password: password to specify when connecting
• reconnectDelayMs: number of milliseconds to wait before trying to reconnect to the database.

Field Summary

protected String	insertRevisionStmtSQL SQL statement appending a new record.
protected String	schemaObjectPrefix Schema object prefix, bean property.
protected String	selectGlobalStmtSQL SQL statement returning the global revision.
protected String	selectRevisionsStmtSQL SQL statement returning all revisions within a range.
protected String	updateGlobalStmtSQL SQL statement updating the global revision.

Constructor Summary

DatabaseJournal()

Method Summary

protected void	append(AppendRecord record, InputStream in, int length) Append a record backed by a file. We have already saved away the revision for this record.
protected void	appending(AppendRecord record) Notification method called by an appended record at creation time. Save away the locked revision inside the newly appended record.
protected void	buildSQLStatements() Builds the SQL statements.
void	close() Close this journal.
protected String	createSchemaSQL(String sql) Creates an SQL statement for schema creation by variable substitution.
protected void	doLock() Lock the journal revision. This journal is locked by incrementing the current value in the table named GLOBAL_REVISION, which effectively write-locks this table.
protected void	doUnlock(boolean successful) Unlock the journal revision.
protected Connection	getConnection() Creates a new database connection.
String	getDriver() Bean getters
String	getPassword()
long	getReconnectDelayMs()
protected RecordIterator	getRecords(long startRevision) Return an iterator over all records after the specified revision.
String	getSchema()
String	getSchemaObjectPrefix()
String	getUrl()
String	getUser()
protected void	init() Completes initialization of this database journal.
void	init(String id, NamespaceResolver resolver) Initialize journal.
protected boolean	schemaExists(DatabaseMetaData metaData) Checks whether the required table(s) exist in the schema.
void	setDriver(String driver) Bean setters
void	setPassword(String password)
void	setReconnectDelayMs(long reconnectDelayMs)
void	setSchema(String schema)
void	setSchemaObjectPrefix(String schemaObjectPrefix)
void	setUrl(String url)
void	setUser(String user)

Methods inherited from class org.apache.jackrabbit.core.journal.AbstractJournal

createProducer, doSync, getConsumer, getId, getNamePathResolver, getProducer, getResolver, lockAndSync, register, sync, unlock, unregister

Methods inherited from class java.lang.Object

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

Field Detail

selectRevisionsStmtSQL

protected String selectRevisionsStmtSQL

SQL statement returning all revisions within a range.

updateGlobalStmtSQL

protected String updateGlobalStmtSQL

SQL statement updating the global revision.

selectGlobalStmtSQL

protected String selectGlobalStmtSQL

SQL statement returning the global revision.

insertRevisionStmtSQL

protected String insertRevisionStmtSQL

SQL statement appending a new record.

schemaObjectPrefix

protected String schemaObjectPrefix

Schema object prefix, bean property.

Constructor Detail

DatabaseJournal

public DatabaseJournal()

Method Detail

init

public void init(String id,
                 NamespaceResolver resolver)
          throws JournalException

Initialize journal.

Specified by:

init in interface Journal

Overrides:

init in class AbstractJournal

Parameters:

id - id this journal should use to write its own records

resolver - resolver used when reading/writing records

Throws:

JournalException - if an error occurs

init

protected void init()
             throws JournalException

Completes initialization of this database journal. Base implementation checks whether the required bean properties driver and url have been specified and optionally deduces a valid schema. Should be overridden by subclasses that use a different way to create a connection and therefore require other arguments.

Throws:

JournalException - if initialization fails

See Also:

getConnection()

getConnection

protected Connection getConnection()
                            throws SQLException

Creates a new database connection. This method is called inside #init(String, org.apache.jackrabbit.name.NamespaceResolver) or when a connection has been dropped and must be reacquired. Base implementation uses java.sql.DriverManager to get the connection. May be overridden by subclasses.

Returns:

new connection

Throws:

SQLException - if an error occurs

See Also:

init()

getRecords

protected RecordIterator getRecords(long startRevision)
                             throws JournalException

Return an iterator over all records after the specified revision. Subclass responsibility.

Specified by:

getRecords in class AbstractJournal

Parameters:

startRevision - start point (exlusive)

Throws:

JournalException - if an error occurs

doLock

protected void doLock()
               throws JournalException

Lock the journal revision. Subclass responsibility.

This journal is locked by incrementing the current value in the table named GLOBAL_REVISION, which effectively write-locks this table. The updated value is then saved away and remembered in the appended record, because a save may entail multiple appends (JCR-884).

Specified by:

doLock in class AbstractJournal

Throws:

JournalException - if an error occurs

doUnlock

protected void doUnlock(boolean successful)

Unlock the journal revision. Subclass responsibility.

Specified by:

doUnlock in class AbstractJournal

Parameters:

successful - flag indicating whether the update process was successful

appending

protected void appending(AppendRecord record)

Notification method called by an appended record at creation time. May be overridden by subclasses to save some context information inside the appended record.

Save away the locked revision inside the newly appended record.

Overrides:

appending in class AbstractJournal

Parameters:

record - record that was appended

append

protected void append(AppendRecord record,
                      InputStream in,
                      int length)
               throws JournalException

Append a record backed by a file. On exit, the new revision must have been set inside the appended record. Subclass responsibility.

We have already saved away the revision for this record.

Specified by:

append in class AbstractJournal

Parameters:

record - record to append

in - input stream

length - number of bytes in input stream

Throws:

JournalException - if an error occurs

close

public void close()

Close this journal. This should release any resources still held by this journal.

schemaExists

protected boolean schemaExists(DatabaseMetaData metaData)
                        throws SQLException

Checks whether the required table(s) exist in the schema. May be overridden by subclasses to allow different table names.

Parameters:

metaData - database meta data

Returns:

true if the schema exists

Throws:

SQLException - if an SQL error occurs

createSchemaSQL

protected String createSchemaSQL(String sql)

Creates an SQL statement for schema creation by variable substitution.

Parameters:

sql - a SQL string which may contain variables to substitute

Returns:

a valid SQL string

buildSQLStatements

protected void buildSQLStatements()

Builds the SQL statements. May be overridden by subclasses to allow different table and/or column names.

getDriver

public String getDriver()

Bean getters

getUrl

public String getUrl()

getSchema

public String getSchema()

getSchemaObjectPrefix

public String getSchemaObjectPrefix()

getUser

public String getUser()

getPassword

public String getPassword()

getReconnectDelayMs

public long getReconnectDelayMs()

setDriver

public void setDriver(String driver)

Bean setters

setUrl

public void setUrl(String url)

setSchema

public void setSchema(String schema)

setSchemaObjectPrefix

public void setSchemaObjectPrefix(String schemaObjectPrefix)

setUser

public void setUser(String user)

setPassword

public void setPassword(String password)

setReconnectDelayMs

public void setReconnectDelayMs(long reconnectDelayMs)