com.github.wuic.nut

Class AbstractNutDao

java.lang.Object

com.github.wuic.util.PollingScheduler<NutDaoListener>

com.github.wuic.nut.AbstractNutDao

All Implemented Interfaces:

NutDao, Runnable

Direct Known Subclasses:

HttpNutDao, PathNutDao, RequestDispatcherNutDao

public abstract class AbstractNutDao
extends PollingScheduler<NutDaoListener>
implements NutDao

An abstract implementation of a NutDao. As any implementation should provides it, this class defines a base path when retrieved nuts, a set of proxies URIs and a polling feature.

The class is designed to be thread safe.

Since:

0.3.1

Version:

1.4

Author:

Guillaume DROUET

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractNutDao.VersionNumberStrategy This class wraps all information required by the AbstractNutDao regarding version number management.
class	AbstractNutDao.WithRootPathNutDao This class represents a modification of the the enclosing class behavior when the NutDao.create(String, ProcessContext) method is called.

Nested classes/interfaces inherited from class com.github.wuic.util.PollingScheduler

PollingScheduler.Polling

Nested classes/interfaces inherited from interface com.github.wuic.nut.dao.NutDao

NutDao.PathFormat

Constructor Summary

Constructors

Constructor and Description
AbstractNutDao(String base, Boolean basePathAsSysProp, String[] proxies, int pollingSeconds, AbstractNutDao.VersionNumberStrategy vns) Builds a new instance.

Method Summary

Methods

Modifier and Type	Method and Description
protected String	absolutePathOf(String relativePath) Computes the absolute path of the given path relative to the DAO's base path.
protected abstract Nut	accessFor(String realPath, NutType type, ProcessContext processContext) Creates an access for the given parameters through a Nut implementation.
List<String>	computeRealPaths(String pathName, NutDao.PathFormat format, ProcessContext processContext) Returns a list of paths depending of the behavior of the dao with the given path.
List<Nut>	create(String pathName, NutDao.PathFormat format, ProcessContext processContext) Creates a list of nuts thanks to the given path.
List<Nut>	create(String path, ProcessContext processContext) Creates a list of nuts thanks to the given path considered as represented in any format.
String	getBasePath() Returns the base path prefixing all paths.
String[]	getProxyUris() Gets the proxy URIs.
protected Future<Long>	getVersionNumber(String path, ProcessContext processContext) Gets the version number for the Nut the given path.
AbstractNutDao.VersionNumberStrategy	getVersionNumberStrategy() Gets the version management strategy.
protected abstract List<String>	listNutsPaths(String pattern) Lists all the nuts path matching the given pattern.
String	proxyUriFor(Nut nut) Returns an URI in a String representation of a proxy serving the given nut.
void	run()
void	save(Nut nut) Saves the give nut.
Boolean	saveSupported() Indicates if this DAO is able to save a nut, which depends on the underlying protocol.
void	shutdown() Shutdowns this DAO by releasing its resources.
String	toString()
NutDao	withRootPath(String rootPath) Returns an instance that prefixes any nut name to be created with the given root path.

Methods inherited from class com.github.wuic.util.PollingScheduler

getLastUpdateTimestampFor, getNutObservers, getPollingInterval, observe, setPollingInterval

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.github.wuic.nut.dao.NutDao

exists, newInputStream, observe

Constructor Detail

AbstractNutDao

public AbstractNutDao(String base,
              Boolean basePathAsSysProp,
              String[] proxies,
              int pollingSeconds,
              AbstractNutDao.VersionNumberStrategy vns)

Builds a new instance.

Parameters:

base - prefix for all paths (an IllegalArgumentException is thrown is null

basePathAsSysProp - true if the base path is a system property

proxies - proxy URIs serving the nut

pollingSeconds - interval in seconds for polling feature (-1 to disable)

vns - fixed version number

Method Detail

run

public void run()

Specified by:

run in interface Runnable

getVersionNumber

protected Future<Long> getVersionNumber(String path,
                            ProcessContext processContext)
                                 throws IOException

Gets the version number for the Nut the given path.

If the AbstractNutDao#versionNumberStrategy#contentBasedVersionNumber value related to ApplicationConfig.CONTENT_BASED_VERSION_NUMBER is true, then the content is read to compute the hash value. However, it uses the last modification timestamp.

Parameters:

processContext - the process context

path - the nut's path

Returns:

the version number

Throws:

IOException - if version number could not be computed

absolutePathOf

protected String absolutePathOf(String relativePath)

Computes the absolute path of the given path relative to the DAO's base path.

Parameters:

relativePath - the relative path

Returns:

the absolute path

create

public List<Nut> create(String path,
               ProcessContext processContext)
                 throws IOException

Creates a list of nuts thanks to the given path considered as represented in any format.

Specified by:

create in interface NutDao

Parameters:

path - the path representing the location of the nut(s)

processContext - the process context calling this method

Returns:

the created nut(s)

Throws:

IOException - if an I/O error occurs when creating the nut

See Also:

NutDao.create(String, com.github.wuic.nut.dao.NutDao.PathFormat, com.github.wuic.ProcessContext)

create

public List<Nut> create(String pathName,
               NutDao.PathFormat format,
               ProcessContext processContext)
                 throws IOException

Creates a list of nuts thanks to the given path.

A NutDao.PathFormat also gives information on the format used in the string representation of the given path.

Specified by:

create in interface NutDao

Parameters:

pathName - the path representing the location of the nut(s)

format - the path format

processContext - the process context calling this method

Returns:

the created nut(s)

Throws:

IOException - if an I/O error occurs when creating the nut

proxyUriFor

public String proxyUriFor(Nut nut)

Returns an URI in a String representation of a proxy serving the given nut.

If many proxies are defined, proxy URI is selected in a round-robin mode. Each time a proxy is used, it won't be reused until all other proxies have been used too.

Specified by:

proxyUriFor in interface NutDao

Parameters:

nut - the nut

Returns:

the proxy URI, null if not proxy is set

save

public void save(Nut nut)

Saves the give nut. An UnsupportedOperationException will be thrown if the implementation supports only nut access.

Specified by:

save in interface NutDao

Parameters:

nut - the nut to save

saveSupported

public Boolean saveSupported()

Indicates if this DAO is able to save a nut, which depends on the underlying protocol.

Specified by:

saveSupported in interface NutDao

Returns:

true if NutDao.save(Nut) is supported, false otherwise

shutdown

public void shutdown()

Shutdowns this DAO by releasing its resources.

Specified by:

shutdown in interface NutDao

withRootPath

public NutDao withRootPath(String rootPath)

Returns an instance that prefixes any nut name to be created with the given root path.

Specified by:

withRootPath in interface NutDao

Parameters:

rootPath - the root path

Returns:

the enclosed instance

computeRealPaths

public List<String> computeRealPaths(String pathName,
                            NutDao.PathFormat format,
                            ProcessContext processContext)
                              throws IOException

Returns a list of paths depending of the behavior of the dao with the given path. In fact, the dao could consider the path as a regex, a directory, etc.

Parameters:

pathName - the path access

format - the path format

processContext - the process context

Returns:

the resulting real paths

Throws:

IOException - if an I/O error occurs when creating the nut

getBasePath

public String getBasePath()

Returns the base path prefixing all paths.

Returns:

the base path

getProxyUris

public String[] getProxyUris()

Gets the proxy URIs.

Returns:

the proxies

getVersionNumberStrategy

public AbstractNutDao.VersionNumberStrategy getVersionNumberStrategy()

Gets the version management strategy.

Returns:

the strategy

listNutsPaths

protected abstract List<String> listNutsPaths(String pattern)
                                       throws IOException

Lists all the nuts path matching the given pattern.

Parameters:

pattern - the pattern

Throws:

IOException - if any I/O error occurs while reading nuts

accessFor

protected abstract Nut accessFor(String realPath,
            NutType type,
            ProcessContext processContext)
                          throws IOException

Creates an access for the given parameters through a Nut implementation.

Parameters:

realPath - the real path to use to access the nut

type - the path's type

processContext - the process context

Returns:

the Nut

Throws:

IOException - if an I/O error occurs while creating access

toString

public String toString()

Overrides:

toString in class Object