Merge pull request eclipse-rdf4j#2792 from eclipse/eclipse-rdf4jGH-2789…

…-values-language-tagged-literal

eclipse-rdf4jGH-2789 added factory methods for language-tagged literals

core/model/src/main/java/org/eclipse/rdf4j/model/util/Values.java

@@ -25,6 +25,7 @@
 import org.eclipse.rdf4j.model.ValueFactory;
 import org.eclipse.rdf4j.model.impl.SimpleValueFactory;
 import org.eclipse.rdf4j.model.impl.ValidatingValueFactory;
+import org.eclipse.rdf4j.model.vocabulary.RDF;
 import org.eclipse.rdf4j.model.vocabulary.XSD;
 
 /**
@@ -206,6 +207,36 @@ public static Literal literal(ValueFactory vf, String lexicalValue) {
 		return vf.createLiteral(Objects.requireNonNull(lexicalValue, "lexicalValue may not be null"));
 	}
 
+	/**
+	 * Creates a new {@link Literal} with the supplied lexical value.
+	 * 
+	 * @param lexicalValue the lexical value for the literal
+	 * @param languageTag  the language tag for the literal.
+	 * 
+	 * @return a new {@link Literal} of type {@link RDF#LANGSTRING}
+	 * 
+	 * @throws NullPointerException if the supplied lexical value or language tag is <code>null</code>.
+	 */
+	public static Literal literal(String lexicalValue, String languageTag) {
+		return literal(VALUE_FACTORY, lexicalValue, languageTag);
+	}
+
+	/**
+	 * Creates a new {@link Literal} with the supplied lexical value.
+	 *
+	 * @param vf           the {@link ValueFactory} to use for creation of the {@link Literal}
+	 * @param lexicalValue the lexical value for the literal
+	 * @param languageTag  the language tag for the literal.
+	 * 
+	 * @return a new {@link Literal} of type {@link RDF#LANGSTRING}
+	 * 
+	 * @throws NullPointerException if any of the input parameters is <code>null</code>
+	 */
+	public static Literal literal(ValueFactory vf, String lexicalValue, String languageTag) {
+		return vf.createLiteral(Objects.requireNonNull(lexicalValue, "lexicalValue may not be null"),
+				Objects.requireNonNull(languageTag, "languageTag may not be null"));
+	}
+
 	/**
 	 * Creates a new {@link Literal} with the supplied lexical value and datatype.
 	 * 

core/model/src/test/java/org/eclipse/rdf4j/model/util/ValuesTest.java

@@ -175,6 +175,43 @@ public void testStringLiteralNull() {
 				.hasMessageContaining("lexicalValue may not be null");
 	}
 
+	@Test
+	public void testLanguageTaggedLiteral() {
+		String lexValue = "a literal";
+		String languageTag = "en";
+		Literal literal = literal(lexValue, languageTag);
+
+		assertThat(literal.getLabel()).isEqualTo(lexValue);
+		assertThat(literal.getLanguage()).isNotEmpty().contains(languageTag);
+		assertThat(literal.getDatatype()).isEqualTo(RDF.LANGSTRING);
+	}
+
+	@Test
+	public void testLanguageTaggedLiteral_InjectedValueFactory() {
+		String lexValue = "a literal";
+		String languageTag = "en";
+		literal(vf, lexValue, languageTag);
+		verify(vf).createLiteral(lexValue, languageTag);
+	}
+
+	@Test
+	public void testLanguageTaggedLiteralNull1() {
+		String lexicalValue = null;
+		String languageTag = "en";
+		assertThatThrownBy(() -> literal(lexicalValue, languageTag))
+				.isInstanceOf(NullPointerException.class)
+				.hasMessageContaining("lexicalValue may not be null");
+	}
+
+	@Test
+	public void testLanguageTaggedLiteralNull2() {
+		String lexicalValue = "a literal";
+		String languageTag = null;
+		assertThatThrownBy(() -> literal(lexicalValue, languageTag))
+				.isInstanceOf(NullPointerException.class)
+				.hasMessageContaining("languageTag may not be null");
+	}
+
 	@Test
 	public void testValidTypedLiteral() {
 		String lexValue = "42";
@@ -209,7 +246,8 @@ public void testTypedLiteralNull1() {
 	@Test
 	public void testTypedLiteralNull2() {
 		String lexValue = "42";
-		assertThatThrownBy(() -> literal(lexValue, null))
+		IRI datatype = null;
+		assertThatThrownBy(() -> literal(lexValue, datatype))
 				.isInstanceOf(NullPointerException.class)
 				.hasMessageContaining("datatype may not be null");
 	}
@@ -573,4 +611,5 @@ public void testLiteralObjectObject() throws Exception {
 		assertThat(l).isNotNull();
 		assertThat(l.getDatatype()).isEqualTo(XSD.STRING);
 	}
+
 }