Class QueryTimeoutInterceptor

java.lang.Object

org.apache.tomcat.jdbc.pool.JdbcInterceptor

org.apache.tomcat.jdbc.pool.interceptor.AbstractCreateStatementInterceptor

org.apache.tomcat.jdbc.pool.interceptor.QueryTimeoutInterceptor

All Implemented Interfaces:

InvocationHandler

public class QueryTimeoutInterceptor
extends AbstractCreateStatementInterceptor

Interceptor that sets a query timeout on every created Statement.

The timeout is applied by the createStatement hook, which only runs for statement-creation calls that pass through this interceptor. When combined with StatementCache, this interceptor must therefore be listed before StatementCache in the jdbcInterceptors configuration. A statement cache hit is served by the cache without invoking the rest of the chain, and a statement recycled into the cache has its query timeout reset to zero, so an interceptor listed after the cache never sees the reuse and the cached statement executes with no timeout. Listed before the cache, the hook runs for every creation request, including the ones the cache serves, and the timeout is re-applied to the reused statement.

Whether a configured timeout actually interrupts a query is up to the driver. A driver that refuses Statement.setQueryTimeout(int) does not stop the statement from being handed out - the pool cannot enforce a timeout itself, so such a statement runs unbounded - and the refusal is reported once per physical connection rather than once per statement, so that the log says what is not in effect without repeating itself for every statement that connection creates.

Field Summary

Fields inherited from class AbstractCreateStatementInterceptor

constructors, CREATE_STATEMENT, CREATE_STATEMENT_IDX, EXECUTE, EXECUTE_BATCH, EXECUTE_LARGE_BATCH, EXECUTE_LARGE_UPDATE, EXECUTE_QUERY, EXECUTE_TYPES, EXECUTE_UPDATE, GET_GENERATED_KEYS, GET_RESULTSET, GET_STATEMENT, PREPARE_CALL, PREPARE_CALL_IDX, PREPARE_STATEMENT, PREPARE_STATEMENT_IDX, RESULTSET_IDX, STATEMENT_TYPE_COUNT, STATEMENT_TYPES

Modifier and Type	Field	Description
protected static final Constructor<?>[]	constructors	the constructors that are used to create statement proxies.
protected static final String	CREATE_STATEMENT	Connection.createStatement()
protected static final int	CREATE_STATEMENT_IDX	Index for AbstractCreateStatementInterceptor.CREATE_STATEMENT in AbstractCreateStatementInterceptor.STATEMENT_TYPES
protected static final String	EXECUTE	Statement.execute(String)
protected static final String	EXECUTE_BATCH	Statement.executeBatch()
protected static final String	EXECUTE_LARGE_BATCH	Statement.executeLargeBatch()
protected static final String	EXECUTE_LARGE_UPDATE	Statement.executeLargeUpdate(String) and its overloads, and PreparedStatement.executeLargeUpdate()
protected static final String	EXECUTE_QUERY	Statement.executeQuery(String)
protected static final String[]	EXECUTE_TYPES	Array of execute type method names
protected static final String	EXECUTE_UPDATE	Statement.executeUpdate(String)
protected static final String	GET_GENERATED_KEYS	Statement.getGeneratedKeys()
protected static final String	GET_RESULTSET	Statement.getResultSet()
protected static final String	GET_STATEMENT	ResultSet.getStatement()
protected static final String	PREPARE_CALL	Connection.prepareCall(String)
protected static final int	PREPARE_CALL_IDX	Index for AbstractCreateStatementInterceptor.PREPARE_CALL in AbstractCreateStatementInterceptor.STATEMENT_TYPES
protected static final String	PREPARE_STATEMENT	Connection.prepareStatement(String)
protected static final int	PREPARE_STATEMENT_IDX	Index for AbstractCreateStatementInterceptor.PREPARE_STATEMENT in AbstractCreateStatementInterceptor.STATEMENT_TYPES
protected static final int	RESULTSET_IDX	Index for AbstractCreateStatementInterceptor.GET_STATEMENT in AbstractCreateStatementInterceptor.STATEMENT_TYPES
protected static final int	STATEMENT_TYPE_COUNT	Count of statement types in AbstractCreateStatementInterceptor.STATEMENT_TYPES
protected static final String[]	STATEMENT_TYPES	Array of statement type method names

Fields inherited from class JdbcInterceptor

ABORT_VAL, CLOSE_VAL, EQUALS_VAL, GETCONNECTION_VAL, HASHCODE_VAL, ISCLOSED_VAL, ISVALID_VAL, ISWRAPPERFOR_VAL, properties, TOSTRING_VAL, UNWRAP_VAL

Modifier and Type	Field	Description
static final String	ABORT_VAL	Connection.abort(java.util.concurrent.Executor) method name
static final String	CLOSE_VAL	Connection.close() method name
static final String	EQUALS_VAL	Object.equals(Object)
static final String	GETCONNECTION_VAL	PooledConnection.getConnection() method name
static final String	HASHCODE_VAL	Object.hashCode()
static final String	ISCLOSED_VAL	Connection.isClosed() method name
static final String	ISVALID_VAL	Connection.isValid(int) method name
static final String	ISWRAPPERFOR_VAL	Wrapper.isWrapperFor(Class) method name
protected Map<String, PoolProperties.InterceptorProperty>	properties	Properties for this interceptor.
static final String	TOSTRING_VAL	Object.toString() method name
static final String	UNWRAP_VAL	Wrapper.unwrap(Class) method name

Constructor Summary

Constructors

Constructor	Description
QueryTimeoutInterceptor()	Default constructor.

Method Summary

Modifier and Type	Method	Description
void	closeInvoked()	No-op; the refusal record belongs to the physical connection, not to the borrow, so ending a borrow has nothing here to clean up.
Object	createStatement(Object proxy, Method method, Object[] args, Object statement, long time)	Sets the query timeout on the created statement if it is a Statement and the timeout value is positive.
void	disconnected(ConnectionPool parent, PooledConnection con, boolean finalizing)	Forgets the reported refusal, as the physical connection this interceptor is attached to is gone: the session that replaces it gets its own refusal recorded and its own warning, the way it gets its own driver to answer the call.
void	setProperties(Map<String, PoolProperties.InterceptorProperty> properties)	Initializes the queryTimeout property from the provided configuration map.

Methods inherited from class AbstractCreateStatementInterceptor

getConstructor, invoke, isExecute, isStatement, process, reset

Modifier and Type	Method	Description
protected Constructor<?>	getConstructor(int idx, Class<?> clazz)	Creates a constructor for a proxy class, if one doesn't already exist.
Object	invoke(Object proxy, Method method, Object[] args)	Gets invoked each time an operation on Connection is invoked.
protected boolean	isExecute(Method method, boolean process)	Returns true if the method that is being invoked matches one of the execute types.
protected boolean	isStatement(Method method, boolean process)	Returns true if the method that is being invoked matches one of the statement types.
protected boolean	process(String[] names, Method method, boolean process)	Returns true if the method that is being invoked matches one of the method names passed in
void	reset(ConnectionPool parent, PooledConnection con)	no-op for this interceptor. no state is stored.

Methods inherited from class JdbcInterceptor

compare, compare, getNext, getProperties, isUseEquals, poolClosed, poolStarted, setNext, setUseEquals

Modifier and Type	Method	Description
boolean	compare(String methodName, Method method)	Compares a method name (String) to a method (Method) JdbcInterceptor.compare(String,String) Uses reference comparison unless the useEquals property is set to true
boolean	compare(String name1, String name2)	Performs a string comparison, using references unless the useEquals property is set to true.
JdbcInterceptor	getNext()	Returns the next interceptor in the chain
Map<String, PoolProperties.InterceptorProperty>	getProperties()	Returns the properties configured for this interceptor
boolean	isUseEquals()	True if the compare method uses the Object.equals(Object) method, false if comparison is done on a reference level.
void	poolClosed(ConnectionPool pool)	This method is invoked by a connection pool when the pool is closed.
void	poolStarted(ConnectionPool pool)	This method is invoked by a connection pool when the pool is first started up, usually when the first connection is requested.
void	setNext(JdbcInterceptor next)	configures the next interceptor in the chain
void	setUseEquals(boolean useEquals)	Set to true if string comparisons (for the JdbcInterceptor.compare(String, Method) and JdbcInterceptor.compare(String, String) methods) should use the Object.equals(Object) method The default is false

Methods inherited from class Object

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

Constructor Details

QueryTimeoutInterceptor

public QueryTimeoutInterceptor()

Default constructor.

Method Details

setProperties

public void setProperties(Map<String, PoolProperties.InterceptorProperty> properties)

Initializes the queryTimeout property from the provided configuration map. A value that is not an integer is not applied and is warned about: the timeout keeps the value it has - for a fresh instance the one-second default - so a misconfigured pool behaves as the default and the warning says so as the bad value is configured. The pool configures an interceptor instance once at pool start, once per physical connection chain, and once when the pool stops, so the report shares the per-connection reporting volume of the driver refusal below.

Overrides:

setProperties in class JdbcInterceptor

Parameters:

properties - map of interceptor properties

createStatement

public Object createStatement(Object proxy,
 Method method,
 Object[] args,
 Object statement,
 long time)

Sets the query timeout on the created statement if it is a Statement and the timeout value is positive.

Specified by:

createStatement in class AbstractCreateStatementInterceptor

Parameters:

proxy - the actual proxy object

method - the method that was called

args - the arguments to the method

statement - the statement that the underlying connection created

time - elapsed time in milliseconds

Returns:

the (possibly wrapped) statement object

disconnected

public void disconnected(ConnectionPool parent,
 PooledConnection con,
 boolean finalizing)

Forgets the reported refusal, as the physical connection this interceptor is attached to is gone: the session that replaces it gets its own refusal recorded and its own warning, the way it gets its own driver to answer the call.

Overrides:

disconnected in class JdbcInterceptor

Parameters:

parent - - the connection pool that this connection belongs to

con - - the pooled connection that holds this connection

finalizing - - if this connection is finalizing. True means that the pooled connection will not reconnect the underlying connection

closeInvoked

public void closeInvoked()

No-op; the refusal record belongs to the physical connection, not to the borrow, so ending a borrow has nothing here to clean up.

Specified by:

closeInvoked in class AbstractCreateStatementInterceptor