org.objectweb.cjdbc.common.sql
Class AbstractRequest

java.lang.Object
  org.objectweb.cjdbc.common.sql.AbstractRequest

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

AbstractWriteRequest, SelectRequest, StoredProcedure, UnknownRequest

public abstract class AbstractRequest

extends java.lang.Object

implements java.io.Serializable

An AbstractRequest defines the skeleton of an SQL request. Requests have to be serializable (at least) for inter-controller communications.

Version:

1.0

Author:

Emmanuel Cecchet , Julie Marguerite , Mathieu Peltier , Marc Herbert

See Also:

Serialized Form

Field Summary

protected int	cacheable Whether this request is cacheable or not.
(package private) java.lang.String	cursorName
private boolean	driverProcessed If set to true, this query is/was interpreted on the driver side, if false the various parameters are encoded and passed as is to the database native driver by the controller.
protected boolean	escapeProcessing Should the backend driver do escape processing before sending to the database?
(package private) int	fetchSize
protected long	id Request unique id (set by the controller).
protected boolean	isAutoCommit Whether this request has been sent in autocommit mode or not.
protected boolean	isParsed Whether the SQL content has been parsed or not.
protected boolean	isReadOnly True if the connection has been set to read-only
private java.lang.String	lineSeparator Set and sent by the driver to the controller.
protected java.lang.String	login Login used to issue this request (must be set by the VirtualDatabaseWorkerThread).
(package private) int	maxRows
(package private) int	requestType
protected java.lang.String	sqlQuery SQL query (should be set in constructor).
protected java.lang.String	sqlSkeleton SQL query skeleton as it appears in PreparedStatements.
protected int	timeoutInSeconds Timeout for this request in seconds, value 0 means no timeout (should be set in constructor).
protected long	transactionId Transaction identifier if this request belongs to a transaction.
protected int	transactionIsolation Transaction isolation level to use when executing the query inside a transaction.

Constructor Summary

AbstractRequest(CJDBCInputStream in, int requestType)
Creates a new AbstractRequest object, deserializing it from an input stream.

AbstractRequest(java.lang.String sqlQuery, boolean escapeProcessing, int timeout, java.lang.String lineSeparator, int requestType)
Default constructor Creates a new AbstractRequest object

Method Summary

abstract void	cloneParsing(AbstractRequest request) Clones the parsing of a request.
void	debug() Displays some debugging information about this request.
boolean	equals(java.lang.Object other) Two requests are equal if they have the same SQL statement, transaction id and login.
int	getCacheAbility() Returns the cacheable status of this request.
java.lang.String	getCursorName() Returns the cursorName value.
boolean	getEscapeProcessing() Returns true if the driver should escape processing before sending to the database?
int	getFetchSize() Returns the fetchSize value.
long	getId() Returns the unique id of this request.
java.lang.String	getLineSeparator() Returns the lineSeparator value.
java.lang.String	getLogin() Returns the login used to issue this request.
int	getMaxRows() Get the maximum number of rows the ResultSet can contain.
java.lang.String	getSQL() Gets the SQL code of this request.
java.lang.String	getSQLShortForm(int nbOfCharacters) Get a short form of this request if the SQL statement exceeds nbOfCharacters.
java.lang.String	getSqlSkeleton()
int	getTimeout() Gets the timeout for this request in seconds.
long	getTransactionId() Gets the identifier of the transaction if this request belongs to a transaction, or -1 if this request does not belong to a transaction.
int	getTransactionIsolation() Returns the transaction isolation level.
boolean	isAlter() Returns true if this request in a ALTER statement.
boolean	isAutoCommit() Returns true if the request should be executed in autocommit mode.
boolean	isCreate() Returns true if this request in a CREATE statement.
boolean	isDDL() Returns true if this request is a DDL (Data Definition Language) statement such as CREATE, ALTER or DROP.
boolean	isDelete() Returns true if this request in a DELETE statement.
boolean	isDML() Returns true if this request is a DML (Data Manipulation Language) statement such SELECT, INSERT, UPDATE or DELETE (see http://www.orafaq.com/faq/Server_Utilities/SQL/faq53.htm) Note that stored procedures are both considered as DDL and DML as they can include both.
boolean	isDriverProcessed() Returns the driverProcessed value.
boolean	isDrop() Returns true if this request in a DROP statement.
boolean	isInsert() Returns true if this request in an INSERT statement.
boolean	isParsed() Returns true if the request SQL content has been already parsed.
boolean	isReadOnly() Returns true if the connection is set to read-only
boolean	isSelect() Returns true if this request in a SELECT statement.
boolean	isUpdate() Returns true if this request in an UPDATE statement.
abstract boolean	needsMacroProcessing() Returns true if this request requires macro (RAND(), NOW(), ...) processing.
abstract void	parse(DatabaseSchema schema, int granularity, boolean isCaseSensitive) Parses the SQL request and extract the selected columns and tables given the DatabaseSchema of the database targeted by this request.
(package private) void	receiveResultSetParams(CJDBCInputStream in) Also fetch ResultSet parameters from the stream.
private java.lang.String	replaceStringWithSpace(java.lang.String s, java.lang.String toReplace) Replaces any given String by a space in a given String.
abstract boolean	returnsResultSet() Does this request returns a ResultSet?
(package private) void	sendResultSetParams(CJDBCOutputStream out) Also serialize ResultSet parameters to the stream.
void	sendToStream(CJDBCOutputStream out, boolean controllerWantsSqlSkeleton) Serialize the request on the output stream by sending only the needed parameters to reconstruct it on the controller.
void	setCacheAbility(int cacheAbility) Set the cacheable status of this request.
void	setCursorName(java.lang.String cursorName) Sets the cursorName value.
void	setDriverProcessed(boolean driverProcessed) Sets the driverProcessed value.
void	setFetchSize(int fetchSize) Sets the fetchSize value.
void	setId(long id) Sets the unique id of this request.
void	setIsAutoCommit(boolean isAutoCommit) Sets the autocommit mode for this request.
void	setIsReadOnly(boolean isReadOnly) Sets the read-only mode for this request.
void	setLogin(java.lang.String login) Sets the login to use to issue this request.
void	setMaxRows(int rows) Set the maximum number of rows in the ResultSet.
void	setSQL(java.lang.String sql) Set the SQL code of this request.
void	setSqlSkeleton(java.lang.String skel)
void	setTimeout(int timeout) Sets the new timeout in seconds for this request.
void	setTransactionId(long id) Sets the transaction identifier this request belongs to.
void	setTransactionIsolation(int isolationLevel) Sets the transaction isolation level that must be used to execute this request
java.lang.String	trimCarriageReturnAndTabs() If the query has a skeleton defined, return the skeleton with all carriage returns and tabs replaced with spaces.

Methods inherited from class java.lang.Object

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

Field Detail

requestType

int requestType

See Also:

RequestType

id

protected transient long id

Request unique id (set by the controller).

sqlQuery

protected java.lang.String sqlQuery

SQL query (should be set in constructor).

sqlSkeleton

protected java.lang.String sqlSkeleton

SQL query skeleton as it appears in PreparedStatements.

login

protected java.lang.String login

Login used to issue this request (must be set by the VirtualDatabaseWorkerThread).

cacheable

protected int cacheable

Whether this request is cacheable or not.

isParsed

protected boolean isParsed

Whether the SQL content has been parsed or not.

maxRows

int maxRows

fetchSize

int fetchSize

cursorName

java.lang.String cursorName

isReadOnly

protected boolean isReadOnly

True if the connection has been set to read-only

isAutoCommit

protected boolean isAutoCommit

Whether this request has been sent in autocommit mode or not.

transactionId

protected long transactionId

Transaction identifier if this request belongs to a transaction. The value is set by the VirtualDatabaseWorkerThread.

transactionIsolation

protected int transactionIsolation

Transaction isolation level to use when executing the query inside a transaction. The value is set by the VirtualDatabaseWorkerThread.

timeoutInSeconds

protected int timeoutInSeconds

Timeout for this request in seconds, value 0 means no timeout (should be set in constructor). This timeout is in seconds, reflecting the jdbc-spec, and is passed as-is to the backends jdbc-driver. Internally converted to ms via getTimeoutMs().

escapeProcessing

protected boolean escapeProcessing

Should the backend driver do escape processing before sending to the database? Simply forwarded to backend driver. No setter for this member, should be set in constructor.

See Also:

Statement.setEscapeProcessing(boolean)

lineSeparator

private java.lang.String lineSeparator

Set and sent by the driver to the controller. Required for parsing the request.

driverProcessed

private boolean driverProcessed

If set to true, this query is/was interpreted on the driver side, if false the various parameters are encoded and passed as is to the database native driver by the controller. Look for "proxy mode" in the documentation.

Constructor Detail

AbstractRequest

public AbstractRequest(java.lang.String sqlQuery,
                       boolean escapeProcessing,
                       int timeout,
                       java.lang.String lineSeparator,
                       int requestType)

Default constructor Creates a new AbstractRequest object

Parameters:

sqlQuery - the SQL query

escapeProcessing - should the driver to escape processing before sending to the database ?

timeout - an int value

lineSeparator - the line separator used in the query

requestType - the request type as defined in RequestType class

See Also:

RequestType

AbstractRequest

public AbstractRequest(CJDBCInputStream in,
                       int requestType)
                throws java.io.IOException

Creates a new AbstractRequest object, deserializing it from an input stream. Has to mirror the serialization method below.

Parameters:

in - the input stream to read from

requestType - the request type as defined in RequestType class

Throws:

java.io.IOException - if a network error occurs

See Also:

RequestType

Method Detail

sendToStream

public void sendToStream(CJDBCOutputStream out,
                         boolean controllerWantsSqlSkeleton)
                  throws java.io.IOException

Serialize the request on the output stream by sending only the needed parameters to reconstruct it on the controller. Has to mirror the deserialization method above.

Parameters:

out - destination CJDBCOutputStream

controllerWantsSqlSkeleton - true if controller wants SQL templates

Throws:

java.io.IOException - if fails

receiveResultSetParams

void receiveResultSetParams(CJDBCInputStream in)
                      throws java.io.IOException

Also fetch ResultSet parameters from the stream. Optionally used by deserializers of those derived requests that expect a ResultSet.

Parameters:

in - input stream

Throws:

java.io.IOException - stream error

sendResultSetParams

void sendResultSetParams(CJDBCOutputStream out)
                   throws java.io.IOException

Also serialize ResultSet parameters to the stream. Optionally used by serializers of those derived requests that expect a ResultSet.

Parameters:

out - output stream

Throws:

java.io.IOException - stream error

needsMacroProcessing

public abstract boolean needsMacroProcessing()

Returns true if this request requires macro (RAND(), NOW(), ...) processing.

Returns:

true if macro processing is required

See Also:

AbstractLoadBalancer.handleMacros(AbstractRequest)

returnsResultSet

public abstract boolean returnsResultSet()

Does this request returns a ResultSet?

Returns:

true is this request will return a ResultSet

isAlter

public final boolean isAlter()

Returns true if this request in a ALTER statement.

Returns:

a boolean value

isCreate

public final boolean isCreate()

Returns true if this request in a CREATE statement.

Returns:

a boolean value

isDelete

public final boolean isDelete()

Returns true if this request in a DELETE statement.

Returns:

a boolean value

isDDL

public final boolean isDDL()

Returns true if this request is a DDL (Data Definition Language) statement such as CREATE, ALTER or DROP. Not supported yet are: TRUNCATE, COMMENT, GRANT and REVOKE (see http://www.orafaq.com/faq/Server_Utilities/SQL/faq53.htm)

Note that stored procedures are both considered as DDL and DML as they can include both.

Returns:

true if this request is a DDL

isDML

public final boolean isDML()

Returns true if this request is a DML (Data Manipulation Language) statement such SELECT, INSERT, UPDATE or DELETE (see http://www.orafaq.com/faq/Server_Utilities/SQL/faq53.htm)

Note that stored procedures are both considered as DDL and DML as they can include both.

Returns:

true if this request is a DDL

isDrop

public final boolean isDrop()

Returns true if this request in a DROP statement.

Returns:

a boolean value

isInsert

public final boolean isInsert()

Returns true if this request in an INSERT statement.

Returns:

a boolean value

isParsed

public boolean isParsed()

Returns true if the request SQL content has been already parsed.

Returns:

a boolean value

isReadOnly

public boolean isReadOnly()

Returns true if the connection is set to read-only

Returns:

a boolean value

isSelect

public final boolean isSelect()

Returns true if this request in a SELECT statement.

Returns:

a boolean value

isUpdate

public final boolean isUpdate()

Returns true if this request in an UPDATE statement.

Returns:

a boolean value

setIsReadOnly

public void setIsReadOnly(boolean isReadOnly)

Sets the read-only mode for this request.

Parameters:

isReadOnly - true if connection is read-only

getCacheAbility

public int getCacheAbility()

Returns the cacheable status of this request. It can be: RequestType.CACHEABLE, RequestType.UNCACHEABLEor RequestType.UNIQUE_CACHEABLE

Returns:

a int value

setCacheAbility

public void setCacheAbility(int cacheAbility)

Set the cacheable status of this request. It can be: RequestType.CACHEABLE, RequestType.UNCACHEABLEor RequestType.UNIQUE_CACHEABLE

Parameters:

cacheAbility - a int value

getEscapeProcessing

public boolean getEscapeProcessing()

Returns true if the driver should escape processing before sending to the database?

Returns:

a boolean value

getId

public long getId()

Returns the unique id of this request.

Returns:

the request id

setId

public void setId(long id)

Sets the unique id of this request.

Parameters:

id - the id to set

isAutoCommit

public boolean isAutoCommit()

Returns true if the request should be executed in autocommit mode.

Returns:

a boolean value

setIsAutoCommit

public void setIsAutoCommit(boolean isAutoCommit)

Sets the autocommit mode for this request.

Parameters:

isAutoCommit - true if autocommit should be used

getLogin

public java.lang.String getLogin()

Returns the login used to issue this request.

Returns:

a String value

getLineSeparator

public java.lang.String getLineSeparator()

Returns the lineSeparator value.

Returns:

Returns the lineSeparator.

setLogin

public void setLogin(java.lang.String login)

Sets the login to use to issue this request.

Parameters:

login - a String value

getSQL

public java.lang.String getSQL()

Gets the SQL code of this request.

Returns:

the SQL query

getSQLShortForm

public java.lang.String getSQLShortForm(int nbOfCharacters)

Get a short form of this request if the SQL statement exceeds nbOfCharacters.

Parameters:

nbOfCharacters - number of characters to include in the short form.

Returns:

the nbOfCharacters first characters of the SQL statement

getMaxRows

public int getMaxRows()

Get the maximum number of rows the ResultSet can contain.

Returns:

maximum number of rows

See Also:

Statement.getMaxRows()

setMaxRows

public void setMaxRows(int rows)

Set the maximum number of rows in the ResultSet. Used only by Statement.

Parameters:

rows - maximum number of rows

See Also:

Statement.setMaxRows(int)

setSQL

public void setSQL(java.lang.String sql)

Set the SQL code of this request. Warning! The request parsing validity is not checked. The caller has to recall parse(DatabaseSchema, int, boolean)if needed.

Parameters:

sql - SQL statement

See Also:

AbstractLoadBalancer.handleMacros(AbstractRequest)

getTimeout

public int getTimeout()

Gets the timeout for this request in seconds.

Returns:

timeout in seconds (0 means no timeout)

setTimeout

public void setTimeout(int timeout)

Sets the new timeout in seconds for this request.

Parameters:

timeout - an int value

See Also:

org.objectweb.cjdbc.controller.scheduler

getTransactionId

public long getTransactionId()

Gets the identifier of the transaction if this request belongs to a transaction, or -1 if this request does not belong to a transaction.

Returns:

transaction identifier or -1

setTransactionId

public void setTransactionId(long id)

Sets the transaction identifier this request belongs to.

Parameters:

id - transaction id

equals

public boolean equals(java.lang.Object other)

Two requests are equal if they have the same SQL statement, transaction id and login.

Parameters:

other - an object

Returns:

a boolean value

parse

public abstract void parse(DatabaseSchema schema,
                           int granularity,
                           boolean isCaseSensitive)
                    throws java.sql.SQLException

Parses the SQL request and extract the selected columns and tables given the DatabaseSchema of the database targeted by this request.

An exception is thrown when the parsing fails. Warning, this method does not check the validity of the request. In particular, invalid request could be parsed without throwing an exception. However, valid SQL request should never throw an exception.

Parameters:

schema - a DatabaseSchema value

granularity - parsing granularity as defined in ParsingGranularities

isCaseSensitive - true if parsing must be case sensitive

Throws:

java.sql.SQLException - if the parsing fails

cloneParsing

public abstract void cloneParsing(AbstractRequest request)

Clones the parsing of a request.

Parameters:

request - the parsed request to clone

trimCarriageReturnAndTabs

public java.lang.String trimCarriageReturnAndTabs()

If the query has a skeleton defined, return the skeleton with all carriage returns and tabs replaced with spaces. If no SQL skeleton is defined, we perform the same processing on the instanciated SQL statement.

Note that if no modification has to be done, the original string is returned else a new string is constructed with the replaced elements.

Returns:

statement with CR replaced by spaces

replaceStringWithSpace

private java.lang.String replaceStringWithSpace(java.lang.String s,
                                                java.lang.String toReplace)

Replaces any given String by a space in a given String.

Parameters:

s - the String to transform

toReplace - the String to replace with spaces

Returns:

the transformed String

getSqlSkeleton

public java.lang.String getSqlSkeleton()

Returns:

the SQL query skeleton given in a PreparedStatement.

setSqlSkeleton

public void setSqlSkeleton(java.lang.String skel)

Parameters:

skel - set the SQL query skeleton given in a PreparedStatement.

isDriverProcessed

public boolean isDriverProcessed()

Returns the driverProcessed value.

Returns:

Returns the driverProcessed.

setDriverProcessed

public void setDriverProcessed(boolean driverProcessed)

Sets the driverProcessed value.

Parameters:

driverProcessed - The driverProcessed to set.

setFetchSize

public void setFetchSize(int fetchSize)

Sets the fetchSize value.

Parameters:

fetchSize - The fetchSize to set.

See Also:

Statement

getFetchSize

public int getFetchSize()

Returns the fetchSize value.

Returns:

Returns the fetchSize.

getTransactionIsolation

public int getTransactionIsolation()

Returns the transaction isolation level.

Returns:

Returns the transaction isolation.

setTransactionIsolation

public void setTransactionIsolation(int isolationLevel)

Sets the transaction isolation level that must be used to execute this request

Parameters:

isolationLevel - the transaction isolation level

getCursorName

public java.lang.String getCursorName()

Returns the cursorName value.

Returns:

Returns the cursorName.

setCursorName

public void setCursorName(java.lang.String cursorName)

Sets the cursorName value.

Parameters:

cursorName - The cursorName to set.

debug

public void debug()

Displays some debugging information about this request.