org.apache.jena

Class JenaRuntime

java.lang.Object

org.apache.jena.JenaRuntime

public class JenaRuntime
extends Object

Methods and constants that define features of the current the environment. Primarily for other parts of the Jena framework.

Field Summary

Fields

Modifier and Type	Field and Description
static String	featureNoCharset The JVM does not implement java.nio.charset.Charset operations (correctly)
static String	featureNoSecurity The JVM does not implement java.security (correctly)
static boolean	isRDF11 The global isRDF11 exists only to support development in Jena2.

Constructor Summary

Constructors

Constructor and Description
JenaRuntime()

Method Summary

Modifier and Type	Method and Description
static String	getLineSeparator()
static String	getMetadata(String key, String defaultValue)
static String	getSystemProperty(String propName)
static String	getSystemProperty(String propName, String defaultValue)
static boolean	runNotUnder(String featureName)
static boolean	runUnder(String featureName)
static void	setFeature(String featureName)

Methods inherited from class java.lang.Object

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

Field Detail

isRDF11

public static boolean isRDF11

The global isRDF11 exists only to support development in Jena2. It is not expected that this flag will be "true" for Jena2 releases.

Jena2 provides RDF 1.0 (AKA RDF 2004) and as much of RDF 1.1 that can be provided without invalidating existing data and applciations. For example, the Turtle family parsers cover the RDF 1.1 defined grammars.

RDF 1.1 does make some changes that will effect some applications. The RDF Working Group do not expect these to be that major but they are visible in some situations.

One of these changes is that literals always have a datatype. RDF 1.0 plain literals (e.g. "foo" and "foo"@en) do not have datatype.

In RDF 1.1:

• string literals without language tag have datatype xsd:string
• string literals with language tag have datatype rdf:langString. They still have a language tag.

In RDF 1.0, "foo" and "foo"^^xsd:string are different RDF terms. Triples :s :p "foo" and :s :p "foo"^^xsd:string are two different RDF triples. Jena memory models provide "same value" semantics, so these can both be found looking for object of "foo" but two such triples are found.

Other storage implementations do not provide these "same value" semantics. Two triples are stored in a graph or in a database.

In RDF 1.1, "foo" and "foo"^^xsd:string are the same RDF term; it is just two different ways to write it. The example triples above are the same triple. Only one triple would be stored in a graph or on disk.

It is common for applications to work either with RDF 1.0 untyped strings or with typed xsd:strings. Mixed working is less common. Mixed working applications will be affected by the changes in RDF 1.1.

Default full RDF 1.1 behaviour is expected in Jena3, with the change of major version number used to indicate the application-visible change.

featureNoSecurity

public static final String featureNoSecurity

The JVM does not implement java.security (correctly)

See Also:

Constant Field Values

featureNoCharset

public static final String featureNoCharset

The JVM does not implement java.nio.charset.Charset operations (correctly)

See Also:

Constant Field Values

Constructor Detail

JenaRuntime

public JenaRuntime()

Method Detail

getMetadata

public static String getMetadata(String key,
                                 String defaultValue)

setFeature

public static void setFeature(String featureName)

runUnder

public static boolean runUnder(String featureName)

runNotUnder

public static boolean runNotUnder(String featureName)

getLineSeparator

public static String getLineSeparator()

getSystemProperty

public static String getSystemProperty(String propName)

getSystemProperty

public static String getSystemProperty(String propName,
                                       String defaultValue)