Package org.apache.sis.setup
Class InstallationResources
- Object
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- InstallationResources
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- Direct Known Subclasses:
InstallationScriptProvider
,ResourcesDownloader
public abstract class InstallationResources extends Object
Resources needed for installation of third-party or optional components.InstallationResources
can be used for downloading large files that may not be of interest to every users, or data that are subject to more restricting terms of use than the Apache license.Examples:Some authorities implemented in Apache SIS modules are listed below. In this list,- The NADCON grid files provide datum shifts data for North America. Since those files are in the public domain, they could be bundled in Apache SIS. But the weight of those files (about 2.4 Mb) is unnecessary for users who do not live in North America.
- On the other hand, the EPSG geodetic dataset is important for most users.
Codes like
"EPSG:4326"
became a de-facto standard in various places like Web Map Services, images encoded in GeoTIFF format, etc. But the EPSG terms of use are more restrictive than the Apache license and require that we inform the users about those conditions.
"Embedded"
is a pseudo-authority for an embedded database containing EPSG and other data. The embedded database is provided as a convenience for avoiding the need to define aSIS_DATA
directory on the local machine.Authorities supported by Apache SIS Authority Provided by Maven module Used by class "EPSG"
org.apache.sis.non-free:sis-epsg
EPSGFactory
"Embedded"
org.apache.sis.non-free:sis-embedded-data
All the above InstallationResources
implementations shall be declared in the following file:
Above registration is usually done automatically when extension modules are added on the classpath. For example adding theMETA-INF/services/org.apache.sis.setup.InstallationResources
org.apache.sis.non-free:sis-epsg
Maven dependency as documented on the Apache SIS web site is the only step needed for allowing Apache SIS to read the EPSG scripts (however SIS still needs an installation directory for writing the database; see above-cited web page for more information).- Since:
- 0.7
Defined in the
sis-utility
module
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Constructor Summary
Constructors Modifier Constructor Description protected
InstallationResources()
For subclass constructors.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description abstract Set<String>
getAuthorities()
Returns identifiers of the resources provided by this instance.abstract String
getLicense(String authority, Locale locale, String mimeType)
Returns the terms of use of the resources distributed by the specified authority, ornull
if none.Object
getResource(String authority, int index)
Returns an installation resource for the given authority, ornull
if not available.abstract String[]
getResourceNames(String authority)
Returns the names of all resources of the specified authority that are distributed by this instance.abstract BufferedReader
openScript(String authority, int resource)
Returns a reader for the resources at the given index.
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Method Detail
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getAuthorities
public abstract Set<String> getAuthorities()
Returns identifiers of the resources provided by this instance. The values recognized by SIS are listed below (note that this list may be expanded in any future SIS versions):Authorities supported by Apache SIS Authority Resources "EPSG"
SQL installation scripts for EPSG geodetic dataset. "Embedded"
Data source of embedded database containing EPSG and other resources. Note:This method may return an empty set if this"Embedded"
is a pseudo-authority for an embedded database containing EPSG and other data. This embedded database is provided by theorg.apache.sis.non-free:sis-embedded-data
module as a convenience for avoiding the need to define aSIS_DATA
directory on the local machine. In this particular case, the resource is more for execution than for installation.InstallationResources
instance did not find the resources (for example because of files not found) or does not have the permission to distribute them.- Returns:
- identifiers of resources that this instance can distribute.
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getLicense
public abstract String getLicense(String authority, Locale locale, String mimeType) throws IOException
Returns the terms of use of the resources distributed by the specified authority, ornull
if none. The terms of use can be returned in either plain text or HTML.Licenses for some supported authorities Authority License "EPSG"
A copy of the http://www.epsg.org/TermsOfUse.aspx page. "Embedded"
Above EPSG license. - Parameters:
authority
- one of the values returned bygetAuthorities()
.locale
- the preferred locale for the terms of use.mimeType
- either"text/plain"
or"text/html"
.- Returns:
- the terms of use in plain text or HTML, or
null
if none. - Throws:
IllegalArgumentException
- if the givenauthority
argument is not one of the expected values.IOException
- if an error occurred while reading the license file.
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getResourceNames
public abstract String[] getResourceNames(String authority) throws IOException
Returns the names of all resources of the specified authority that are distributed by this instance. The resources will be used in the order they appear in the array. Examples:"EPSG"
authority: the resource names are the filenames of all SQL scripts to execute. One of the first script creates tables, followed by a script that populates tables with data, followed by a script that creates foreigner keys."Embedded"
pseudo-authority: the database name, which is"SpatialMetadata"
. When embedded, this database is read-only.
- Parameters:
authority
- one of the values returned bygetAuthorities()
.- Returns:
- the names of all resources of the given authority that are distributed by this instance.
- Throws:
IllegalArgumentException
- if the givenauthority
argument is not one of the expected values.IOException
- if fetching the resource names required an I/O operation and that operation failed.
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getResource
public Object getResource(String authority, int index) throws IOException
Returns an installation resource for the given authority, ornull
if not available. The return value may be an instance of any type, at implementation choice. This may be for example aURL
referencing the actual resource.The default implementation returns
null
. A null value means that the resource is fetched byopenScript(String, int)
instead than this method. We do not returnURL
to text files in order to ensure that the file is opened with proper character encoding.- Parameters:
authority
- one of the values returned bygetAuthorities()
.index
- index of the resource to get, from 0 inclusive togetResourceNames(authority).length
exclusive.- Returns:
- the resource as an URL or any other type (at implementation choice), or
null
if not available. - Throws:
IllegalArgumentException
- if the givenauthority
argument is not one of the expected values.IndexOutOfBoundsException
- if the givenresource
argument is out of bounds.IOException
- if an error occurred while fetching the resource.- Since:
- 0.8
- See Also:
ClassLoader.getResource(String)
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openScript
public abstract BufferedReader openScript(String authority, int resource) throws IOException
Returns a reader for the resources at the given index. The resource may be a SQL script or any other resources readable as a text. The returnedBufferedReader
instance shall be closed by the caller.- Parameters:
authority
- one of the values returned bygetAuthorities()
.resource
- index of the script to open, from 0 inclusive togetResourceNames(authority).length
exclusive.- Returns:
- a reader for the installation script content.
- Throws:
IllegalArgumentException
- if the givenauthority
argument is not one of the expected values.IndexOutOfBoundsException
- if the givenresource
argument is out of bounds.IOException
- if an error occurred while creating the reader.
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