dk.netarkivet.harvester.datamodel
Class DBSpecifics

java.lang.Object
  extended by dk.netarkivet.common.utils.SettingsFactory<DBSpecifics>
      extended by dk.netarkivet.harvester.datamodel.DBSpecifics
Direct Known Subclasses:
DerbySpecifics, MySQLSpecifics, PostgreSQLSpecifics

public abstract class DBSpecifics
extends SettingsFactory<DBSpecifics>

Defines database specific implementations used by the Harvester. The actual actual implementation which is loaded is defined by the CommonSettings.DB_SPECIFICS_CLASS setting. See the sub class list for available implementations


Field Summary
(package private)  org.apache.commons.logging.Log log
           
 
Constructor Summary
DBSpecifics()
           
 
Method Summary
abstract  boolean connectionIsValid(java.sql.Connection connection, int validityTimeout)
          Checks that the connection is valid (i.e.
abstract  void createFrontierReportMonitorTable()
          Create the frontierReportMonitor table in the database.
protected abstract  void createGlobalCrawlerTrapExpressions()
          Creates the initial (version 1) of table 'global_crawler_trap_expressions'.
protected abstract  void createGlobalCrawlerTrapLists()
          Creates the initial (version 1) of table 'global_crawler_trap_lists'.
abstract  void createRunningJobsHistoryTable()
          Create the frontierReportMonitor table in the database.
abstract  void createRunningJobsMonitorTable()
          Create the frontierReportMonitor table in the database.
abstract  void dropJobConfigsTmpTable(java.sql.Connection c, java.lang.String tableName)
          Dispose of a temporary table gotten with getTemporaryTable.
abstract  java.lang.String getDriverClassName()
          Get the name of the JDBC driver class that handles interfacing to this server.
static DBSpecifics getInstance()
          Get the singleton instance of the DBSpecifics implementation class.
abstract  java.lang.String getJobConfigsTmpTable(java.sql.Connection c)
          Get a temporary table for short-time use.
abstract  java.lang.String getOrderByLimitAndOffsetSubClause(long limit, long offset)
          Formats the LIMIT sub-clause of an SQL order clause.
protected abstract  void migrateConfigurationsv3ov4()
          Migrates the 'configurations' table from version 3 to version 4.
protected abstract  void migrateFullharvestsv2tov3()
          Migrates the 'fullharvests' table from version 2 to version 3.
protected abstract  void migrateJobsv3tov4()
          Migrates the 'jobs' table from version 3 to version 4 consisting of a change of the field forcemaxbytes from int to bigint and setting its default to -1.
protected abstract  void migrateJobsv4tov5()
          Migrates the 'jobs' table from version 4 to version 5 consisting of adding new fields 'resubmitted_as_job' and 'submittedDate'.
abstract  boolean supportsClob()
          Returns true if the target RDBMS supports CLOBs.
 void updateTable(java.lang.String tableName, int toVersion)
          Update a table to a newer version, if necessary.
 
Methods inherited from class dk.netarkivet.common.utils.SettingsFactory
getInstance
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

log

org.apache.commons.logging.Log log
Constructor Detail

DBSpecifics

public DBSpecifics()
Method Detail

getInstance

public static DBSpecifics getInstance()
Get the singleton instance of the DBSpecifics implementation class.

Returns:
An instance of DBSpecifics with implementations for a given DB.

getJobConfigsTmpTable

public abstract java.lang.String getJobConfigsTmpTable(java.sql.Connection c)
                                                throws java.sql.SQLException
Get a temporary table for short-time use. The table should be disposed of with dropTemporaryTable. The table has two columns domain_name varchar(Constants.MAX_NAME_SIZE) + config_name varchar(Constants.MAX_NAME_SIZE) All rows in the table must be deleted at commit or rollback.

Parameters:
c - The DB connection to use.
Returns:
The name of the created table
Throws:
java.sql.SQLException - if there is a problem getting the table.

dropJobConfigsTmpTable

public abstract void dropJobConfigsTmpTable(java.sql.Connection c,
                                            java.lang.String tableName)
Dispose of a temporary table gotten with getTemporaryTable. This can be expected to be called from within a finally clause, so it mustn't throw exceptions.

Parameters:
c - The DB connection to use.
tableName - The name of the temporarily created table.

getDriverClassName

public abstract java.lang.String getDriverClassName()
Get the name of the JDBC driver class that handles interfacing to this server.

Returns:
The name of a JDBC driver class

updateTable

public void updateTable(java.lang.String tableName,
                        int toVersion)
Update a table to a newer version, if necessary. This will check the schemaversions table to see the current version and perform a table-specific update if required.

Parameters:
tableName - The table to update
toVersion - The version to update the table to.
Throws:
IllegalState - If the table is an unsupported version, and the toVersion is less than the current version of the table
NotImplementedException - If no method exists for migration from current version of the table to the toVersion of the table.
IOFailure - in case of problems in interacting with the database

migrateJobsv3tov4

protected abstract void migrateJobsv3tov4()
Migrates the 'jobs' table from version 3 to version 4 consisting of a change of the field forcemaxbytes from int to bigint and setting its default to -1. Furthermore the default value for field num_configs is set to 0.

Throws:
IOFailure - in case of problems in interacting with the database

migrateJobsv4tov5

protected abstract void migrateJobsv4tov5()
Migrates the 'jobs' table from version 4 to version 5 consisting of adding new fields 'resubmitted_as_job' and 'submittedDate'.

Throws:
IOFailure - in case of problems in interacting with the database

migrateConfigurationsv3ov4

protected abstract void migrateConfigurationsv3ov4()
Migrates the 'configurations' table from version 3 to version 4. This consists of altering the default value of field 'maxbytes' to -1.


migrateFullharvestsv2tov3

protected abstract void migrateFullharvestsv2tov3()
Migrates the 'fullharvests' table from version 2 to version 3. This consists of altering the default value of field 'maxbytes' to -1.


createGlobalCrawlerTrapLists

protected abstract void createGlobalCrawlerTrapLists()
Creates the initial (version 1) of table 'global_crawler_trap_lists'.


createGlobalCrawlerTrapExpressions

protected abstract void createGlobalCrawlerTrapExpressions()
Creates the initial (version 1) of table 'global_crawler_trap_expressions'.


connectionIsValid

public abstract boolean connectionIsValid(java.sql.Connection connection,
                                          int validityTimeout)
                                   throws java.sql.SQLException
Checks that the connection is valid (i.e. still open on the server side). This implementation can be overriden if a specific RDBM is not handling the Connection.isValid(int) JDBC4 method properly.

Parameters:
connection - the connection to check
validityTimeout - the time in seconds to wait for the database operation used to validate the connection to complete. If the timeout period expires before the operation completes, this method returns false.
Returns:
true if the connection is valid false otherwise.
Throws:
java.sql.SQLException
See Also:
Connection.isValid(int)

getOrderByLimitAndOffsetSubClause

public abstract java.lang.String getOrderByLimitAndOffsetSubClause(long limit,
                                                                   long offset)
Formats the LIMIT sub-clause of an SQL order clause. This sub-clause allows to paginate query results and its syntax might be dependant on the target RDBMS

Parameters:
limit - the maximum number of rows to fetch.
offset - the starting offset in the full query results.
Returns:
the proper sub-clause.

supportsClob

public abstract boolean supportsClob()
Returns true if the target RDBMS supports CLOBs. If possible seedlists will be stored as CLOBs.

Returns:
true if CLOBs are supported, false otherwise.

createFrontierReportMonitorTable

public abstract void createFrontierReportMonitorTable()
Create the frontierReportMonitor table in the database.


createRunningJobsHistoryTable

public abstract void createRunningJobsHistoryTable()
Create the frontierReportMonitor table in the database.


createRunningJobsMonitorTable

public abstract void createRunningJobsMonitorTable()
Create the frontierReportMonitor table in the database.