org.lateralnz.c3d
Class DatabaseEngine

java.lang.Object
  org.lateralnz.c3d.DatabaseEngine

All Implemented Interfaces:

Constants, MessageListener

public class DatabaseEngine
extends java.lang.Object
implements Constants, MessageListener

core 'database' functionality -- basically this is the interceptor for all SQL statements so we can cache resultsets, refresh the cache and so on.

Field Summary

Fields inherited from interface org.lateralnz.common.util.Constants

AMPERSAND, AND, APPLICATION_X_WWW_FORM_URLENCODED, ASTERISK, AT, BACK_SLASH, CHAR_LEFT_CHEV, CHAR_RIGHT_CHEV, COLON, COMMA, CRLF, DASH, DELETE, DOLLAR, DOT, DOT_CLASS, DOT_JAVA, EIGHT, EMPTY, EQUALS, FALSE, FILE_SEPARATOR, FIVE, FORWARD_SLASH, FOUR, FULLSTOP, HASH, HAT, INSERT, LEFT_BRACE, LEFT_BRACKET, LEFT_CHEV, MAX_LEN_APPCODE, MAX_LEN_APPGROUP, MAX_LEN_MSGCODE, MAX_LEN_MSGTEXT, MINUS_ONE, N, NEWLINE, NINE, NO, NULL_STRING, OFF, ON, ONE, ONE_DAY, ONE_HOUR, ONE_MINUTE, ONE_WEEK, PATH_SEPARATOR, PERCENT, PIPE, PLUS, QUESTION_MARK, QUOTE, REQUIRED, REQUIRES_NEW, RETURN, RIGHT_BRACE, RIGHT_BRACKET, RIGHT_CHEV, SELECT, SEMICOLON, SEVEN, SINGLE_QUOTE, SIX, SPACE, SQ_LEFT_BRACKET, SQ_RIGHT_BRACKET, SUPPORTS, TEXT_HTML, TEXT_PLAIN, TEXT_XML, THREE, TRUE, TWO, UNDERSCORE, UPDATE, UTF_8, Y, YES, ZERO

Method Summary

protected void	commit(DCConnection conn)
protected ResultWrapper	execute(DCStatement st)
java.sql.ResultSet	getCachedResultSet(java.lang.String cacheName, java.lang.String sql)
java.util.List	getCachedResultsetNames(java.lang.String cacheName)
java.util.List	getCacheNames()
static DatabaseEngine	getInstance(java.lang.String dbname, java.util.Properties props)
protected java.lang.String[]	getKeyColumnData(int[] keyColumns, java.sql.ResultSet rs) return the column data based on an array of primary key columns.
protected int[]	getPrimaryKeyColumns(java.lang.String cacheName, java.sql.ResultSetMetaData meta)
protected java.lang.String	getProperty(java.lang.String name)
void	handle(Message msg)
protected void	rollback(DCConnection conn) rollback a connection (get rid of operations list)
protected void	setCachedResultSet(java.lang.String cacheName, java.lang.String sql, java.sql.ResultSet rs) add a resultset to the cache
protected void	setKeyToResultSetLink(java.lang.String cacheName, java.lang.String[] rsKeys, java.lang.String sql) link a key to a resultset
void	triggerCacheChanges(java.util.ArrayList ll)
protected boolean	validate(java.lang.String user, java.lang.String password) validate user access to this 'database'

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static final DatabaseEngine getInstance(java.lang.String dbname,
                                               java.util.Properties props)
                                        throws java.sql.SQLException

Throws:

java.sql.SQLException

commit

protected void commit(DCConnection conn)
               throws java.sql.SQLException

Throws:

java.sql.SQLException

execute

protected ResultWrapper execute(DCStatement st)
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

getCacheNames

public java.util.List getCacheNames()

getCachedResultsetNames

public java.util.List getCachedResultsetNames(java.lang.String cacheName)
                                       throws java.sql.SQLException

Throws:

java.sql.SQLException

getKeyColumnData

protected final java.lang.String[] getKeyColumnData(int[] keyColumns,
                                                    java.sql.ResultSet rs)
                                             throws java.sql.SQLException

return the column data based on an array of primary key columns. For example, if the primary keys are in columns 1, 5 and 6 of the resultset, this will return the data in those columns as a 3 element array.

Throws:

java.sql.SQLException

getPrimaryKeyColumns

protected int[] getPrimaryKeyColumns(java.lang.String cacheName,
                                     java.sql.ResultSetMetaData meta)
                              throws java.sql.SQLException

Throws:

java.sql.SQLException

getCachedResultSet

public java.sql.ResultSet getCachedResultSet(java.lang.String cacheName,
                                             java.lang.String sql)
                                      throws java.sql.SQLException

Throws:

java.sql.SQLException

getProperty

protected java.lang.String getProperty(java.lang.String name)

handle

public void handle(Message msg)

Specified by:

handle in interface MessageListener

triggerCacheChanges

public void triggerCacheChanges(java.util.ArrayList ll)
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

rollback

protected void rollback(DCConnection conn)

rollback a connection (get rid of operations list)

setKeyToResultSetLink

protected void setKeyToResultSetLink(java.lang.String cacheName,
                                     java.lang.String[] rsKeys,
                                     java.lang.String sql)
                              throws java.sql.SQLException

link a key to a resultset

Parameters:

cacheName - the cache we're linking in

rsKeys - the primary key data to use as key

sql - the sql query used to generate the resultset

Throws:

java.sql.SQLException

setCachedResultSet

protected void setCachedResultSet(java.lang.String cacheName,
                                  java.lang.String sql,
                                  java.sql.ResultSet rs)
                           throws java.sql.SQLException

add a resultset to the cache

Throws:

java.sql.SQLException

validate

protected boolean validate(java.lang.String user,
                           java.lang.String password)

validate user access to this 'database'