java.lang.Object
- com.github.ddth.queue.impl.AbstractQueue<ID,DATA>
- - com.github.ddth.queue.impl.AbstractEphemeralSupportQueue<ID,DATA>
  - - com.github.ddth.queue.impl.JdbcQueue<ID,DATA>

All Implemented Interfaces:

IQueue<ID,DATA>, AutoCloseable

Direct Known Subclasses:

BaseUniversalJdbcQueue
```
public abstract class JdbcQueue<ID,DATA>
extends AbstractEphemeralSupportQueue<ID,DATA>
```
Abstract JDBC implementation of IQueue.
Features:
- Queue-size support: yes
- Ephemeral storage support: yes
- Ephemeral-size support: yes
Implementation:
- Queue storage & Ephemeral storage are 2 database tables, same structure!
- take():
  - Obtain a database Connection.
  - Check if ephemeral size is full or not.
  - Call _takeWithRetries(Connection, int, int); which, in turn:
    - Start a database transaction.
    - Read a message off queue storage by calling peekFromQueueStorage(Connection).
    - Remove the message from queue (call removeFromQueueStorage(Connection, IQueueMessage)) and out to ephemeral storage (call putToEphemeralStorage(Connection, IQueueMessage)).
    - Commit transaction if all above operations were successful, rollback transaction otherwise.
- finish(IQueueMessage):
  - Obtain a database Connection.
  - Call _finishWithRetries(Connection, IQueueMessage, int, int); which, in turn:
    - Call removeFromEphemeralStorage(Connection, IQueueMessage).
- getOrphanMessages(long):
  - Obtain a database Connection.
  - Call _getOrphanMessagesWithRetries(long, Connection, int, int); which, in turn:
    - Start a database transaction.
    - Call getOrphanMessagesFromEphemeralStorage(Connection, long).
    - Commit transaction.
- AbstractQueue.queue(IQueueMessage), AbstractQueue.requeue(IQueueMessage) and AbstractQueue.requeueSilent(IQueueMessage): inherit from AbstractQueue and override doPutToQueue(IQueueMessage, PutToQueueCase)
  - If queueCase parameter is AbstractQueue.PutToQueueCase.REQUEUE, call _requeueWithRetries(Connection, IQueueMessage, int, int); which, in turn:
    - Start a database transactions.
    - Call removeFromEphemeralStorage(Connection, IQueueMessage).
    - Call putToQueueStorage(Connection, IQueueMessage).
    - Commit transaction.
  - If queueCase parameter is AbstractQueue.PutToQueueCase.REQUEUE_SILENT, call _requeueSilentWithRetries(Connection, IQueueMessage, int, int); which, in turn:
    - Start a database transactions.
    - Call removeFromEphemeralStorage(Connection, IQueueMessage).
    - Call putToQueueStorage(Connection, IQueueMessage).
    - Commit transaction.
  - Otherwise, call _queueWithRetries(Connection, IQueueMessage, int, int); which, in turn:
    - Call putToQueueStorage(Connection, IQueueMessage)
Since:

0.1.0

Author:

Thanh Ba Nguyen

Nested Class Summary
- Nested classes/interfaces inherited from class com.github.ddth.queue.impl.AbstractQueue
  AbstractQueue.PutToQueueCase

Field Summary

Fields
Modifier and Type Field Description

static int DEFAULT_MAX_RETRIES

static int DEFAULT_TRANX_ISOLATION_LEVEL
- Fields inherited from interface com.github.ddth.queue.IQueue
  SIZE_NOT_SUPPORTED

Constructor Summary

Constructors
Constructor Description

JdbcQueue()

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`protected void`	`_finishWithRetries(Connection conn, IQueueMessage<ID,DATA> msg, int numRetries, int maxRetries)`	Perform "finish" action, retry if deadlock.
`protected Collection<? extends IQueueMessage<ID,DATA>>`	`_getOrphanMessagesWithRetries(long thresholdTimestampMs, Connection conn, int numRetries, int maxRetries)`	Get all orphan messages (messages that were left in ephemeral storage for a long time), retry if deadlock.
`protected boolean`	`_queueWithRetries(Connection conn, IQueueMessage<ID,DATA> immutableMsg, int numRetries, int maxRetries)`	Queue a message, retry if deadlock.
`protected boolean`	`_requeueSilentWithRetries(Connection conn, IQueueMessage<ID,DATA> immutableMsg, int numRetries, int maxRetries)`	Re-queue (silentlt) a message, retry if deadlock.
`protected boolean`	`_requeueWithRetries(Connection conn, IQueueMessage<ID,DATA> immutableMsg, int numRetries, int maxRetries)`	Re-queue a message, retry if deadlock.
`protected IQueueMessage<ID,DATA>`	`_takeWithRetries(Connection conn, int numRetries, int maxRetries)`	Take a message from queue, retry if deadlock.
`protected com.github.ddth.dao.jdbc.IJdbcHelper`	`buildJdbcHelper()`	Build an `IJdbcHelper` to be used by this JDBC queue.
`void`	`destroy()`	Destroy method.
`protected boolean`	`doPutToQueue(IQueueMessage<ID,DATA> msg, AbstractQueue.PutToQueueCase queueCase)`	Put a message to the queue storage.
`protected int`	`doSize(Connection conn, String sql, String field, Object... params)`
`int`	`ephemeralSize()`	Get number of items currently in ephemeral storage.
`protected int`	`ephemeralSize(Connection conn)`	Get number of items currently in ephemeral storage.
`protected int`	`executeWithRetries(int numRetries, int maxRetries, boolean transactionMode, Connection conn, String sql, Object... params)`	Execute a query, retry if deadlock.
`protected int`	`executeWithRetries(int numRetries, int maxRetries, boolean transactionMode, Connection conn, String sql, Map<String,Object> params)`	Execute a query, retry if deadlock.
`protected <T> T`	`executeWithRetries(int numRetries, int maxRetries, Supplier<T> sqlRunner)`	Execute queries, retry if deadlock.
`void`	`finish(IQueueMessage<ID,DATA> msg)`	Called when finish processing the message to cleanup ephemeral storage.
`DataSource`	`getDataSource()`	Getter for `dataSource`.
`com.github.ddth.dao.jdbc.IJdbcHelper`	`getJdbcHelper()`	Getter for `jdbcHelper`.
`int`	`getMaxRetries()`	Max number of retires for DB-operations.
`Collection<IQueueMessage<ID,DATA>>`	`getOrphanMessages(long thresholdTimestampMs)`	Get all orphan messages (messages that were left in ephemeral storage for a long time).
`protected abstract Collection<? extends IQueueMessage<ID,DATA>>`	`getOrphanMessagesFromEphemeralStorage(Connection conn, long thresholdTimestampMs)`	Primitive operation: Get all orphan messages (messages that were left in ephemeral storage for a long time).
`String`	`getTableName()`	Name of database table to store queue messages.
`String`	`getTableNameEphemeral()`	Name of database table to store ephemeral messages.
`int`	`getTransactionIsolationLevel()`	Transaction isolation level used in DB-operations.
`JdbcQueue<ID,DATA>`	`init()`	Initializing method.
`protected abstract IQueueMessage<ID,DATA>`	`peekFromQueueStorage(Connection conn)`	Primitive operation: Read (but not removed) message from head of queue storage.
`protected abstract boolean`	`putToEphemeralStorage(Connection conn, IQueueMessage<ID,DATA> msg)`	Primitive operation: Put a message to the ephemeral storage.
`protected abstract boolean`	`putToQueueStorage(Connection conn, IQueueMessage<ID,DATA> msg)`	Primitive operation: Put a message to tail of the queue storage.
`int`	`queueSize()`	Get number of items currently in queue storage.
`protected int`	`queueSize(Connection conn)`	Get number of items currently in queue storage.
`protected IQueueMessage<ID,DATA>`	`readFromEphemeralStorage(Connection conn, IQueueMessage<ID,DATA> msg)`	Deprecated. deprecated since 1.0.0, use `readFromEphemeralStorage(Connection, Object)`
`protected abstract IQueueMessage<ID,DATA>`	`readFromEphemeralStorage(Connection conn, ID id)`	Primitive operation: Read (but not removed) a message from the ephemeral storage.
`protected abstract boolean`	`removeFromEphemeralStorage(Connection conn, IQueueMessage<ID,DATA> msg)`	Primitive operation: Remove a message from the queue storage.
`protected abstract boolean`	`removeFromQueueStorage(Connection conn, IQueueMessage<ID,DATA> msg)`	Primitive operation: Remove a message from the queue storage.
`JdbcQueue<ID,DATA>`	`setDataSource(DataSource dataSource)`	Setter for `dataSource`.
`JdbcQueue<ID,DATA>`	`setJdbcHelper(com.github.ddth.dao.jdbc.IJdbcHelper jdbcHelper)`	Setter for `jdbcHelper`.
`protected JdbcQueue<ID,DATA>`	`setJdbcHelper(com.github.ddth.dao.jdbc.IJdbcHelper jdbcHelper, boolean setMyOwnJdbcHelper)`	Setter for `jdbcHelper`.
`JdbcQueue<ID,DATA>`	`setMaxRetries(int maxRetries)`	Max number of retires for DB-operations.
`JdbcQueue<ID,DATA>`	`setTableName(String tableName)`	Name of database table to store queue messages.
`JdbcQueue<ID,DATA>`	`setTableNameEphemeral(String tableNameEphemeral)`	Name of database table to store ephemeral messages.
`JdbcQueue<ID,DATA>`	`setTransactionIsolationLevel(int transactionIsolationLevel)`	Transaction isolation level used in DB-operations.
`IQueueMessage<ID,DATA>`	`take()`	Take a message out of queue.

Methods inherited from class com.github.ddth.queue.impl.AbstractEphemeralSupportQueue
getEphemeralDisabled, getEphemeralMaxSize, isEphemeralDisabled, setEphemeralDisabled, setEphemeralMaxSize

Methods inherited from class com.github.ddth.queue.impl.AbstractQueue
close, createMessage, createMessage, createMessage, deserialize, deserialize, getMessageFactory, getQueueName, getSerDeser, queue, requeue, requeueSilent, serialize, setMessageFactory, setQueueName, setSerDeser

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_MAX_RETRIES
```
public static final int DEFAULT_MAX_RETRIES
```
    See Also:
    
    Constant Field Values
  - DEFAULT_TRANX_ISOLATION_LEVEL
```
public static final int DEFAULT_TRANX_ISOLATION_LEVEL
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - JdbcQueue
```
public JdbcQueue()
```
- Method Detail
  - setTableName
```
public JdbcQueue<ID,DATA> setTableName(String tableName)
```
    Name of database table to store queue messages.
    
    Parameters:
    
    tableName -
    
    Returns:
  - getTableName
```
public String getTableName()
```
    Name of database table to store queue messages.
    
    Returns:
  - setTableNameEphemeral
```
public JdbcQueue<ID,DATA> setTableNameEphemeral(String tableNameEphemeral)
```
    Name of database table to store ephemeral messages.
    
    Parameters:
    
    tableNameEphemeral -
    
    Returns:
  - getTableNameEphemeral
```
public String getTableNameEphemeral()
```
    Name of database table to store ephemeral messages.
    
    Returns:
  - setTransactionIsolationLevel
```
public JdbcQueue<ID,DATA> setTransactionIsolationLevel(int transactionIsolationLevel)
```
    Transaction isolation level used in DB-operations.
    
    Parameters:
    
    transactionIsolationLevel -
    
    Returns:
  - getTransactionIsolationLevel
```
public int getTransactionIsolationLevel()
```
    Transaction isolation level used in DB-operations.
    
    Returns:
  - getJdbcHelper
```
public com.github.ddth.dao.jdbc.IJdbcHelper getJdbcHelper()
```
    Getter for jdbcHelper.
    
    Returns:
    
    Since:
    
    0.5.0
  - setJdbcHelper
```
protected JdbcQueue<ID,DATA> setJdbcHelper(com.github.ddth.dao.jdbc.IJdbcHelper jdbcHelper,
                                                 boolean setMyOwnJdbcHelper)
```
    Setter for jdbcHelper.
    
    Parameters:
    
    jdbcHelper -
    
    setMyOwnJdbcHelper -
    
    Returns:
    
    Since:
    
    0.7.1
  - setJdbcHelper
```
public JdbcQueue<ID,DATA> setJdbcHelper(com.github.ddth.dao.jdbc.IJdbcHelper jdbcHelper)
```
    Setter for jdbcHelper.
    
    Parameters:
    
    jdbcHelper -
    
    Returns:
    
    Since:
    
    0.5.1.1
  - getDataSource
```
public DataSource getDataSource()
```
    Getter for dataSource.
    
    Returns:
    
    Since:
    
    0.6.2.5
  - setDataSource
```
public JdbcQueue<ID,DATA> setDataSource(DataSource dataSource)
```
    Setter for dataSource.
    
    Parameters:
    
    dataSource -
    
    Returns:
    
    Since:
    
    0.6.2.5
  - setMaxRetries
```
public JdbcQueue<ID,DATA> setMaxRetries(int maxRetries)
```
    Max number of retires for DB-operations.
    
    Parameters:
    
    maxRetries -
    
    Returns:
  - getMaxRetries
```
public int getMaxRetries()
```
    Max number of retires for DB-operations.
    
    Returns:
  - buildJdbcHelper
```
protected com.github.ddth.dao.jdbc.IJdbcHelper buildJdbcHelper()
```
    Build an IJdbcHelper to be used by this JDBC queue.
    
    Returns:
    
    Since:
    
    0.6.2.6
  - init
```
public JdbcQueue<ID,DATA> init()
                              throws Exception
```
    Initializing method.
    
    Overrides:
    
    init in class AbstractQueue<ID,DATA>
    
    Returns:
    
    Throws:
    
    Exception
  - destroy
```
public void destroy()
```
    Destroy method.
    
    Overrides:
    
    destroy in class AbstractQueue<ID,DATA>
  - peekFromQueueStorage
```
protected abstract IQueueMessage<ID,DATA> peekFromQueueStorage(Connection conn)
```
    Primitive operation: Read (but not removed) message from head of queue storage.
    
    Parameters:
    
    conn -
    
    Returns:
  - readFromEphemeralStorage
```
protected IQueueMessage<ID,DATA> readFromEphemeralStorage(Connection conn,
                                                                IQueueMessage<ID,DATA> msg)
```
    Deprecated.
    deprecated since 1.0.0, use readFromEphemeralStorage(Connection, Object)
    
    Primitive operation: Read (but not removed) a message from the ephemeral storage.
    
    Parameters:
    
    conn -
    
    msg -
    
    Returns:
    
    Since:
    
    0.2.1
  - readFromEphemeralStorage
```
protected abstract IQueueMessage<ID,DATA> readFromEphemeralStorage(Connection conn,
                                                                         ID id)
```
    Primitive operation: Read (but not removed) a message from the ephemeral storage.
    
    Parameters:
    
    conn -
    
    id -
    
    Returns:
    
    Since:
    
    1.0.0
  - getOrphanMessagesFromEphemeralStorage
```
protected abstract Collection<? extends IQueueMessage<ID,DATA>> getOrphanMessagesFromEphemeralStorage(Connection conn,
                                                                                                            long thresholdTimestampMs)
```
    Primitive operation: Get all orphan messages (messages that were left in ephemeral storage for a long time).
    
    Parameters:
    
    conn -
    
    thresholdTimestampMs - get all orphan messages that were queued before this timestamp
    
    Returns:
    
    Since:
    
    0.2.0
  - putToQueueStorage
```
protected abstract boolean putToQueueStorage(Connection conn,
                                             IQueueMessage<ID,DATA> msg)
```
    Primitive operation: Put a message to tail of the queue storage.
    
    Parameters:
    
    conn -
    
    msg -
    
    Returns:
  - putToEphemeralStorage
```
protected abstract boolean putToEphemeralStorage(Connection conn,
                                                 IQueueMessage<ID,DATA> msg)
```
    Primitive operation: Put a message to the ephemeral storage.
    
    Parameters:
    
    conn -
    
    msg -
  - removeFromQueueStorage
```
protected abstract boolean removeFromQueueStorage(Connection conn,
                                                  IQueueMessage<ID,DATA> msg)
```
    Primitive operation: Remove a message from the queue storage.
    
    Parameters:
    
    conn -
    
    msg -
    
    Returns:
  - removeFromEphemeralStorage
```
protected abstract boolean removeFromEphemeralStorage(Connection conn,
                                                      IQueueMessage<ID,DATA> msg)
```
    Primitive operation: Remove a message from the queue storage.
    
    Parameters:
    
    conn -
    
    msg -
    
    Returns:
  - executeWithRetries
```
protected int executeWithRetries(int numRetries,
                                 int maxRetries,
                                 boolean transactionMode,
                                 Connection conn,
                                 String sql,
                                 Map<String,Object> params)
```
    Execute a query, retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Parameters:
    
    numRetries -
    
    maxRetries -
    
    transactionMode -
    
    conn -
    
    sql -
    
    params -
    
    Returns:
    
    number of affected rows
    
    Since:
    
    1.0.0
  - executeWithRetries
```
protected int executeWithRetries(int numRetries,
                                 int maxRetries,
                                 boolean transactionMode,
                                 Connection conn,
                                 String sql,
                                 Object... params)
```
    Execute a query, retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Parameters:
    
    numRetries -
    
    maxRetries -
    
    transactionMode -
    
    conn -
    
    sql -
    
    params -
    
    Returns:
    
    number of affected rows
    
    Since:
    
    1.0.0
  - executeWithRetries
```
protected <T> T executeWithRetries(int numRetries,
                                   int maxRetries,
                                   Supplier<T> sqlRunner)
```
    Execute queries, retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Type Parameters:
    
    T -
    
    Parameters:
    
    numRetries -
    
    maxRetries -
    
    sqlRunner -
    
    Returns:
    
    Since:
    
    1.0.0
  - _queueWithRetries
```
protected boolean _queueWithRetries(Connection conn,
                                    IQueueMessage<ID,DATA> immutableMsg,
                                    int numRetries,
                                    int maxRetries)
```
    Queue a message, retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Parameters:
    
    conn -
    
    immutableMsg -
    
    numRetries -
    
    maxRetries -
    
    Returns:
  - _requeueSilentWithRetries
```
protected boolean _requeueSilentWithRetries(Connection conn,
                                            IQueueMessage<ID,DATA> immutableMsg,
                                            int numRetries,
                                            int maxRetries)
```
    Re-queue (silentlt) a message, retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Parameters:
    
    conn -
    
    immutableMsg -
    
    numRetries -
    
    maxRetries -
    
    Returns:
  - _requeueWithRetries
```
protected boolean _requeueWithRetries(Connection conn,
                                      IQueueMessage<ID,DATA> immutableMsg,
                                      int numRetries,
                                      int maxRetries)
```
    Re-queue a message, retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Parameters:
    
    conn -
    
    immutableMsg -
    
    numRetries -
    
    maxRetries -
    
    Returns:
  - doPutToQueue
```
protected boolean doPutToQueue(IQueueMessage<ID,DATA> msg,
                               AbstractQueue.PutToQueueCase queueCase)
```
    Put a message to the queue storage.
    Sub-class implements this method.
    
    Specified by:
    
    doPutToQueue in class AbstractQueue<ID,DATA>
    
    Returns:
  - _finishWithRetries
```
protected void _finishWithRetries(Connection conn,
                                  IQueueMessage<ID,DATA> msg,
                                  int numRetries,
                                  int maxRetries)
```
    Perform "finish" action, retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Note: the supplied queue message is mutable.
    
    Parameters:
    
    conn -
    
    msg -
    
    numRetries -
    
    maxRetries -
  - finish
```
public void finish(IQueueMessage<ID,DATA> msg)
```
    Called when finish processing the message to cleanup ephemeral storage.
    Implementation flow:
    
    Remove message from ephemeral storage.
    
    Note: ephemeral storage implementation is optional, depends on implementation.
  - _takeWithRetries
```
protected IQueueMessage<ID,DATA> _takeWithRetries(Connection conn,
                                                        int numRetries,
                                                        int maxRetries)
```
    Take a message from queue, retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Parameters:
    
    conn -
    
    numRetries -
    
    maxRetries -
    
    Returns:
  - take
```
public IQueueMessage<ID,DATA> take()
                                  throws QueueException.EphemeralIsFull
```
    Take a message out of queue.
    Implementation flow:
    
    Read message from head of queue storage.
    
    Write message to ephemeral storage.
    
    Remove message from queue storage.
    
    Note: ephemeral storage implementation is optional, depends on implementation.
    Returns:
    
    Throws:
    
    QueueException.EphemeralIsFull - if the ephemeral storage is full
  - _getOrphanMessagesWithRetries
```
protected Collection<? extends IQueueMessage<ID,DATA>> _getOrphanMessagesWithRetries(long thresholdTimestampMs,
                                                                                           Connection conn,
                                                                                           int numRetries,
                                                                                           int maxRetries)
```
    Get all orphan messages (messages that were left in ephemeral storage for a long time), retry if deadlock.
    Note: http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
    
    InnoDB uses automatic row-level locking. You can get deadlocks even in the case of transactions that just insert or delete a single row. That is because these operations are not really "atomic"; they automatically set locks on the (possibly several) index records of the row inserted or deleted.
    
    Parameters:
    
    thresholdTimestampMs -
    
    conn -
    
    numRetries -
    
    maxRetries -
    
    Returns:
    
    Since:
    
    0.2.0
  - getOrphanMessages
```
public Collection<IQueueMessage<ID,DATA>> getOrphanMessages(long thresholdTimestampMs)
```
    Get all orphan messages (messages that were left in ephemeral storage for a long time).
    
    Parameters:
    
    thresholdTimestampMs - message is orphan if message's timestampMillis + thresholdTimestampMs < now . Which means getOrphanMessages(10000) will return orphan messages that have stayed in ephemeral storage for more than 10000 milliseconds.
    
    Returns:
    
    null or empty collection if there is no orphan message
  - doSize
```
protected int doSize(Connection conn,
                     String sql,
                     String field,
                     Object... params)
```
    Parameters:
    
    conn -
    
    sql -
    
    field -
    
    params -
    
    Returns:
    
    Since:
    
    1.0.0
  - queueSize
```
protected int queueSize(Connection conn)
```
    Get number of items currently in queue storage.
    
    Parameters:
    
    conn -
    
    Returns:
    
    Since:
    
    0.5.0
  - ephemeralSize
```
protected int ephemeralSize(Connection conn)
```
    Get number of items currently in ephemeral storage.
    
    Parameters:
    
    conn -
    
    Returns:
    
    Since:
    
    0.5.0
  - queueSize
```
public int queueSize()
```
    Get number of items currently in queue storage.
    
    Returns:
    
    negative number if queue size can not be queried
  - ephemeralSize
```
public int ephemeralSize()
```
    Get number of items currently in ephemeral storage.
    Note: ephemeral storage implementation is optional, depends on implementation.
    
    Returns:
    
    negative number if ephemeral size can not be queried

Modifier and Type	Field	Description
`static int`	`DEFAULT_MAX_RETRIES`
`static int`	`DEFAULT_TRANX_ISOLATION_LEVEL`

Class JdbcQueue<ID,​DATA>

Nested Class Summary

Nested classes/interfaces inherited from class com.github.ddth.queue.impl.AbstractQueue

Field Summary

Fields inherited from interface com.github.ddth.queue.IQueue

Constructor Summary

Method Summary

Methods inherited from class com.github.ddth.queue.impl.AbstractEphemeralSupportQueue

Methods inherited from class com.github.ddth.queue.impl.AbstractQueue

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_MAX_RETRIES

DEFAULT_TRANX_ISOLATION_LEVEL

Constructor Detail

JdbcQueue

Method Detail

setTableName

getTableName

setTableNameEphemeral

getTableNameEphemeral

setTransactionIsolationLevel

getTransactionIsolationLevel

getJdbcHelper

setJdbcHelper

setJdbcHelper

getDataSource

setDataSource

setMaxRetries

getMaxRetries

buildJdbcHelper

init

destroy

peekFromQueueStorage

readFromEphemeralStorage

readFromEphemeralStorage

getOrphanMessagesFromEphemeralStorage

putToQueueStorage

putToEphemeralStorage

removeFromQueueStorage

removeFromEphemeralStorage

executeWithRetries

executeWithRetries

executeWithRetries

_queueWithRetries

_requeueSilentWithRetries

_requeueWithRetries

doPutToQueue

_finishWithRetries

finish

_takeWithRetries

take

_getOrphanMessagesWithRetries

getOrphanMessages

doSize

queueSize

ephemeralSize

queueSize

ephemeralSize

Class JdbcQueue<ID,DATA>