feat(#215): Add several useful constructors for SaxonDocument

src/main/java/com/jcabi/xml/SaxonDocument.java

@@ -29,7 +29,14 @@
  */
 package com.jcabi.xml;
 
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
 import java.io.StringReader;
+import java.net.URI;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
 import java.util.List;
 import java.util.stream.Collectors;
 import javax.xml.namespace.NamespaceContext;
@@ -81,14 +88,72 @@ public final class SaxonDocument implements XML {
     /**
      * Public constructor from XML as string text.
      * @param text XML document body.
+     * @since 0.28.0
      */
     public SaxonDocument(final String text) {
         this(SaxonDocument.node(text));
     }
 
+    /**
+     * Public constructor from XML as byte array.
+     * @param data XML document body as byte array.
+     * @since 0.28.1
+     */
+    public SaxonDocument(final byte[] data) {
+        this(SaxonDocument.node(new String(data, StandardCharsets.UTF_8)));
+    }
+
+    /**
+     * Public constructor from XML saved in a filesystem.
+     * @param path Path to XML file in a filesystem.
+     * @since 0.28.1
+     */
+    public SaxonDocument(final Path path) {
+        this(path.toFile());
+    }
+
+    /**
+     * Public constructor from XML saved in a filesystem.
+     * @param file XML file in a filesystem.
+     * @since 0.28.1
+     */
+    public SaxonDocument(final File file) {
+        this(SaxonDocument.node(new StreamSource(file)));
+    }
+
+    /**
+     * Public constructor from XML reached by URL.
+     * @param url URL of XML document.
+     * @throws IOException If fails.
+     * @since 0.28.1
+     */
+    public SaxonDocument(final URL url) throws IOException {
+        this(SaxonDocument.node(new TextResource(url).toString()));
+    }
+
+    /**
+     * Public constructor from XML reached by URI.
+     * @param uri URI of XML document.
+     * @throws IOException If fails.
+     * @since 0.28.1
+     */
+    public SaxonDocument(final URI uri) throws IOException {
+        this(SaxonDocument.node(new TextResource(uri).toString()));
+    }
+
+    /**
+     * Public constructor from XML as input stream.
+     * @param stream Input stream with XML document.
+     * @since 0.28.1
+     */
+    public SaxonDocument(final InputStream stream) {
+        this(SaxonDocument.node(new StreamSource(stream)));
+    }
+
     /**
      * Public constructor from Saxon XML document node.
      * @param xml Saxon XML document node.
+     * @since 0.28.0
      */
     public SaxonDocument(final XdmNode xml) {
         this.xdm = xml;
@@ -145,12 +210,20 @@ public Node node() {
      * @return Saxon XML document node.
      */
     private static XdmNode node(final String text) {
+        return SaxonDocument.node(new StreamSource(new StringReader(text)));
+    }
+
+    /**
+     * Build Saxon XML document node from XML source.
+     * @param source XML.
+     * @return Saxon XML document node.
+     */
+    private static XdmNode node(final StreamSource source) {
         try {
-            return SaxonDocument.DOC_BUILDER
-                .build(new StreamSource(new StringReader(text)));
+            return SaxonDocument.DOC_BUILDER.build(source);
         } catch (final SaxonApiException exception) {
             throw new IllegalArgumentException(
-                String.format("SaxonDocument can't parse XML: %s", text),
+                String.format("SaxonDocument can't parse XML from source '%s'", source),
                 exception
             );
         }

src/test/java/com/jcabi/xml/SaxonDocumentTest.java

@@ -29,16 +29,102 @@
  */
 package com.jcabi.xml;
 
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 
 /**
  * Test case for {@link SaxonDocument}.
  * @since 0.28
  */
 final class SaxonDocumentTest {
 
+    /**
+     * Default XML content for tests.
+     */
+    private static final String DEFAULT_XML = "<o><o base='a'/></o>";
+
+    /**
+     * Default assertion message that will be used in many test assertions.
+     */
+    private static final String ASSERTION_MSG = "Can't create Saxon XML document from '%s'";
+
+    @Test
+    void createsFromFile(@TempDir final Path temp) throws IOException {
+        final Path xml = SaxonDocumentTest.xmlFile(temp);
+        final File file = xml.toFile();
+        MatcherAssert.assertThat(
+            String.format(SaxonDocumentTest.ASSERTION_MSG, file),
+            new SaxonDocument(file).xpath("//o[@base]"),
+            Matchers.hasSize(1)
+        );
+    }
+
+    @Test
+    void createsFromPath(@TempDir final Path temp) throws IOException {
+        final Path xml = SaxonDocumentTest.xmlFile(temp);
+        MatcherAssert.assertThat(
+            String.format(SaxonDocumentTest.ASSERTION_MSG, xml),
+            new SaxonDocument(xml).xpath("//o[@base]"),
+            Matchers.hasSize(1)
+        );
+    }
+
+    @Test
+    void createsFromByteArray() {
+        final Charset utf = StandardCharsets.UTF_8;
+        final byte[] bytes = SaxonDocumentTest.DEFAULT_XML.getBytes(utf);
+        MatcherAssert.assertThat(
+            String.format(SaxonDocumentTest.ASSERTION_MSG, new String(bytes, utf)),
+            new SaxonDocument(bytes).xpath("//o[@base]"),
+            Matchers.hasSize(1)
+        );
+    }
+
+    @Test
+    void createsFromUrl() throws IOException {
+        final URL resource = this.getClass().getResource("simple.xml");
+        MatcherAssert.assertThat(
+            String.format(SaxonDocumentTest.ASSERTION_MSG, resource),
+            new SaxonDocument(resource).xpath("//simple"),
+            Matchers.hasSize(1)
+        );
+    }
+
+    @Test
+    void createsFromUri() throws URISyntaxException, IOException {
+        final URI resource = this.getClass().getResource("simple.xml").toURI();
+        MatcherAssert.assertThat(
+            String.format(SaxonDocumentTest.ASSERTION_MSG, resource),
+            new SaxonDocument(resource).xpath("//simple"),
+            Matchers.hasSize(1)
+        );
+    }
+
+    @Test
+    void createsFromStream() {
+        MatcherAssert.assertThat(
+            String.format(SaxonDocumentTest.ASSERTION_MSG, SaxonDocumentTest.DEFAULT_XML),
+            new SaxonDocument(
+                new ByteArrayInputStream(
+                    SaxonDocumentTest.DEFAULT_XML.getBytes(StandardCharsets.UTF_8)
+                )
+            ).xpath("//o[@base]"),
+            Matchers.hasSize(1)
+        );
+    }
+
     @Test
     void findsXpathWithConcatFunctionThatReturnsSeveralItems() {
         MatcherAssert.assertThat(
@@ -60,4 +146,16 @@ void findsXpathWithStringJoinFunctionThatReturnsSeveralItems() {
             Matchers.hasItems("a", "b|2", "c")
         );
     }
+
+    /**
+     * Creates XML file.
+     * @param temp Temporary directory where file will be created
+     * @return Path to created file
+     * @throws IOException If something goes wrong
+     */
+    private static Path xmlFile(final Path temp) throws IOException {
+        final Path xml = temp.resolve("test.xml");
+        Files.write(xml, SaxonDocumentTest.DEFAULT_XML.getBytes(StandardCharsets.UTF_8));
+        return xml;
+    }
 }