XMLReaders patch

gistfile1.diff

Index: core/src/java/org/jdom2/input/SAXBuilder.java
===================================================================
--- core/src/java/org/jdom2/input/SAXBuilder.java	(revision 1727)
+++ core/src/java/org/jdom2/input/SAXBuilder.java	(working copy)
@@ -224,7 +224,7 @@
 	/**
 	 * Creates a new JAXP-based SAXBuilder. The underlying parser will validate
 	 * (using DTD) or not according to the given parameter. If you want Schema
-	 * validation then use SAXBuilder(XMLReaders.XSDVALIDATOR)
+	 * validation then use SAXBuilder(XMLReaders.getXSDValidating())
 	 * 
 	 * @see SAXBuilder#SAXBuilder(XMLReaderJDOMFactory, SAXHandlerFactory,
 	 *      JDOMFactory)
Index: core/src/java/org/jdom2/input/sax/XMLReaders.java
===================================================================
--- core/src/java/org/jdom2/input/sax/XMLReaders.java	(revision 1727)
+++ core/src/java/org/jdom2/input/sax/XMLReaders.java	(working copy)
@@ -56,125 +56,163 @@
 
 import javax.xml.XMLConstants;
 import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.parsers.SAXParser;
 import javax.xml.parsers.SAXParserFactory;
 import javax.xml.validation.Schema;
 import javax.xml.validation.SchemaFactory;
 
+import org.jdom2.JDOMException;
 import org.xml.sax.SAXException;
 import org.xml.sax.XMLReader;
 
-import org.jdom2.JDOMException;
-
 /**
- * An enumeration of {@link XMLReaderJDOMFactory} that allows for a single
- * central location to create XMLReaders. The Singletons (members) of this
- * enumeration can produce the most common XMLReaders: non-validating, XSD
+ * A set of {@link XMLReaderJDOMFactory} that allows for a single central location to create
+ * XMLReaders. The members of this class can produce the most common XMLReaders: non-validating, XSD
  * validating, and DocType validating.
  * <p>
- * See the {@link org.jdom2.input.sax package documentation} for details of how
- * to create the SAXParser you desire.
+ * See the {@link org.jdom2.input.sax package documentation} for details of how to create the
+ * SAXParser you desire.
  * 
  * @see org.jdom2.input.sax
  * @author Rolf Lear
  */
-public enum XMLReaders implements XMLReaderJDOMFactory {
+public class XMLReaders implements XMLReaderJDOMFactory {
 
-	/**
-	 * The non-validating singleton
-	 */
-	NONVALIDATING(0),
+    public static enum Validation {
+        NONE(false), DTD(true), SCHEMA(true);
 
-	/**
-	 * The DTD-validating Singleton
-	 */
-	DTDVALIDATING(1),
+        private final boolean validate;
 
-	/**
-	 * The XSD-validating Singleton
-	 */
-	XSDVALIDATING(2);
+        private Validation(boolean validate) {
+            this.validate = validate;
+        }
 
-	/** the actual SAXParserFactory in the respective singletons. */
-	private final SAXParserFactory jaxpfactory;
-	private final Exception failcause;
-	/** Is this a validating parser */
-	private final boolean validates;
+        public final boolean isValidating() {
+            return this.validate;
+        }
+    }
 
-	/** Private constructor */
-	private XMLReaders(int validate) {
-		SAXParserFactory fac = SAXParserFactory.newInstance();
-		boolean val = false;
-		Exception problem = null;
-		// All JDOM parsers are namespace aware.
-		fac.setNamespaceAware(true);
-		switch (validate) {
-			case 0:
-				fac.setValidating(false);
-				break;
-			case 1:
-				fac.setValidating(true);
-				val = true;
-				break;
-			case 2:
-				fac.setValidating(false);
-				try {
-					SchemaFactory sfac = SchemaFactory.
-							newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
-					Schema schema = sfac.newSchema();
-					fac.setSchema(schema);
-					val = true;
-				} catch (SAXException se) {
-					// we could not get a validating system, set the fac to null
-					fac = null;
-					problem = se;
-				} catch (IllegalArgumentException iae) {
-					// this system does not support XSD Validation.... which is true for android!
-					// we could not get a validating system, set the fac to null
-					fac = null;
-					problem = iae;
-				} catch (UnsupportedOperationException uoe) {
-					// SAXParserFactory throws this exception when setSchema is called.
-					// Therefore every factory throws this exception unless it overrides
-					// setSchema. A popular example is Apache Xerces SAXParserFactoryImpl
-					// before version 2.7.0.
-					fac = null;
-					problem = uoe;
-				}
-				break;
-		}
-		jaxpfactory = fac;
-		validates = val;
-		failcause = problem;
-	}
+    /**
+     * The non-validating instance
+     */
+    public static final XMLReaders NONVALIDATING = new XMLReaders(Validation.NONE);
 
-	/**
-	 * Get a new XMLReader from this JAXP-based {@link XMLReaderJDOMFactory}.
-	 * <p>
-	 * 
-	 * @return a new XMLReader instance.
-	 * @throws JDOMException
-	 *         if there is a problem creating the XMLReader
-	 */
-	@Override
-	public XMLReader createXMLReader() throws JDOMException {
-		if (jaxpfactory == null) {
-			throw new JDOMException("It was not possible to configure a " +
-					"suitable XMLReader to support " + this, failcause);
-		}
-		try {
-			return jaxpfactory.newSAXParser().getXMLReader();
-		} catch (SAXException e) {
-			throw new JDOMException(
-					"Unable to create a new XMLReader instance", e);
-		} catch (ParserConfigurationException e) {
-			throw new JDOMException(
-					"Unable to create a new XMLReader instance", e);
-		}
-	}
+    /**
+     * The DTD-validating instance
+     */
+    public static final XMLReaders DTDVALIDATING = new XMLReaders(Validation.DTD);
 
-	@Override
-	public boolean isValidating() {
-		return validates;
-	}
+    private static XMLReaders XSDVALIDATING;
 
+    /**
+     * Create a new instance that validates using XSD. I.e. this calls
+     * {@link SchemaFactory#newInstance(String)} with {@link XMLConstants#W3C_XML_SCHEMA_NS_URI}.
+     * 
+     * @return a new instance.
+     * @throws JDOMException if a new instance couldn't be configured.
+     */
+    public static final XMLReaders createXSDValidating() throws JDOMException {
+        try {
+            final SchemaFactory sfac = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
+            final Schema schema = sfac.newSchema();
+            final XMLReaders res = new XMLReaders(Validation.SCHEMA);
+            res.setSchema(schema);
+            return res;
+        } catch (Exception e) {
+            throw new JDOMException("Could not configure", e);
+        }
+    }
+
+    /**
+     * Return the instance that validates using XSD, {@link #createXSDValidating() initialising} it
+     * if necessary.
+     * 
+     * @return the instance that validates using XSD
+     * @throws JDOMException if this was never called and a new instance couldn't be configured, in
+     *         that case the next call will try again (allowing to change the lookup result, see
+     *         {@link #createXSDValidating()}).
+     * @see #setXSDValidating(XMLReaders)
+     */
+    public static final XMLReaders getXSDValidating() throws JDOMException {
+        synchronized (XMLReaders.class) {
+            if (XSDVALIDATING == null) {
+                XSDVALIDATING = createXSDValidating();
+            }
+            return XSDVALIDATING;
+        }
+    }
+
+    /**
+     * Set the XSD instance.
+     * 
+     * @param instance the instance to be returned by {@link #getXSDValidating()}.
+     * @throws JDOMException if the instance wasn't returned by {@link #createXSDValidating()}.
+     */
+    public static final void setXSDValidating(final XMLReaders instance) throws JDOMException {
+        if (instance.getValidation() != Validation.SCHEMA)
+            throw new JDOMException("Not a schema validation : " + instance);
+        synchronized (XMLReaders.class) {
+            XSDVALIDATING = instance;
+        }
+    }
+
+    /** the actual SAXParserFactory in the respective singletons. */
+    private final SAXParserFactory jaxpfactory;
+    private final Validation val;
+
+    /** Private constructor */
+    private XMLReaders(final Validation val) {
+        final SAXParserFactory fac = SAXParserFactory.newInstance();
+        // All JDOM parsers are namespace aware.
+        fac.setNamespaceAware(true);
+        fac.setValidating(val == Validation.DTD);
+        this.val = val;
+        synchronized (this) {
+            this.jaxpfactory = fac;
+        }
+    }
+
+    protected final void setSchema(final Schema schema) throws JDOMException {
+        if (this.getValidation() != Validation.SCHEMA)
+            throw new JDOMException("Validation isn't schema : " + this.getValidation());
+        synchronized (this) {
+            this.jaxpfactory.setSchema(schema);
+        }
+    }
+
+    /**
+     * Get a new XMLReader from this JAXP-based {@link XMLReaderJDOMFactory}.
+     * <p>
+     * 
+     * @return a new XMLReader instance.
+     * @throws JDOMException if there is a problem creating the XMLReader
+     */
+    @Override
+    public final XMLReader createXMLReader() throws JDOMException {
+        try {
+            final SAXParser newSAXParser;
+            synchronized (this) {
+                newSAXParser = this.jaxpfactory.newSAXParser();
+            }
+            return newSAXParser.getXMLReader();
+        } catch (SAXException e) {
+            throw new JDOMException("Unable to create a new XMLReader instance", e);
+        } catch (ParserConfigurationException e) {
+            throw new JDOMException("Unable to create a new XMLReader instance", e);
+        }
+    }
+
+    public final Validation getValidation() {
+        return this.val;
+    }
+
+    @Override
+    public final boolean isValidating() {
+        return this.val.isValidating();
+    }
+
+    @Override
+    public String toString() {
+        return this.getClass().getSimpleName() + (!this.isValidating() ? " not validating" : " validating using " + this.getValidation());
+    }
 }
Index: test/src/java/org/jdom2/test/cases/input/TestDOMBuilder.java
===================================================================
--- test/src/java/org/jdom2/test/cases/input/TestDOMBuilder.java	(revision 1727)
+++ test/src/java/org/jdom2/test/cases/input/TestDOMBuilder.java	(working copy)
@@ -79,7 +79,7 @@
 			Element domroot = db.build(HelpTestDOMBuilder.getRoot(domdoc));
 			
 			SAXBuilder sb = new SAXBuilder(xsdvalidate
-					? XMLReaders.XSDVALIDATING
+					? XMLReaders.getXSDValidating()
 					: XMLReaders.NONVALIDATING );
 			sb.setExpandEntities(false);
 			
Index: test/src/java/org/jdom2/test/cases/input/TestSAXBuilder.java
===================================================================
--- test/src/java/org/jdom2/test/cases/input/TestSAXBuilder.java	(revision 1727)
+++ test/src/java/org/jdom2/test/cases/input/TestSAXBuilder.java	(working copy)
@@ -440,12 +440,12 @@
 	}
 	
 	@Test
-	public void testGetSetXMLReaderFactory() {
+	public void testGetSetXMLReaderFactory() throws JDOMException {
 		SAXBuilder sb = new SAXBuilder();
 		XMLReaderJDOMFactory xrjf = sb.getXMLReaderFactory();
 		assertTrue(xrjf == XMLReaders.NONVALIDATING);
-		sb.setXMLReaderFactory(XMLReaders.XSDVALIDATING);
-		assertTrue(sb.getXMLReaderFactory() == XMLReaders.XSDVALIDATING);
+		sb.setXMLReaderFactory(XMLReaders.getXSDValidating());
+		assertTrue(sb.getXMLReaderFactory() == XMLReaders.getXSDValidating());
 		sb.setXMLReaderFactory(null);
 		assertTrue(xrjf == XMLReaders.NONVALIDATING);
 	}
Index: test/src/java/org/jdom2/test/cases/input/TestSAXComplexSchema.java
===================================================================
--- test/src/java/org/jdom2/test/cases/input/TestSAXComplexSchema.java	(revision 1727)
+++ test/src/java/org/jdom2/test/cases/input/TestSAXComplexSchema.java	(working copy)
@@ -83,8 +83,8 @@
 	 * Test method for {@link org.jdom.input.SAXBuilder#build(java.io.File)}.
 	 */
 	@Test
-	public void testBuildFileNewSAX() throws IOException {
-		SAXBuilder builder = new SAXBuilder(XMLReaders.XSDVALIDATING);
+	public void testBuildFileNewSAX() throws IOException, JDOMException {
+		SAXBuilder builder = new SAXBuilder(XMLReaders.getXSDValidating());
 		
 		URL rurl = FidoFetch.getFido().getURL("/xsdcomplex/input.xml");
 		
Index: test/src/java/org/jdom2/test/cases/input/sax/TestXMLReaderSingletons.java
===================================================================
--- test/src/java/org/jdom2/test/cases/input/sax/TestXMLReaderSingletons.java	(revision 1727)
+++ test/src/java/org/jdom2/test/cases/input/sax/TestXMLReaderSingletons.java	(working copy)
@@ -50,7 +50,7 @@
 
 	@Test
 	public void testXSDValidatingReader() throws JDOMException, IOException {
-		SAXBuilder builder = new SAXBuilder(XMLReaders.XSDVALIDATING);
+		SAXBuilder builder = new SAXBuilder(XMLReaders.getXSDValidating());
 		assertTrue(builder.isValidating());
 		Document doc = builder.build(FidoFetch.getFido().getURL("/xsdcomplex/input.xml"));
 		assertEquals("test", doc.getRootElement().getName());
@@ -65,8 +65,8 @@
 	}
 
 	@Test
-	public void testXSDValidatingReaderFails() {
-		SAXBuilder builder = new SAXBuilder(XMLReaders.XSDVALIDATING);
+	public void testXSDValidatingReaderFails() throws JDOMException {
+		SAXBuilder builder = new SAXBuilder(XMLReaders.getXSDValidating());
 		assertTrue(builder.isValidating());
 		try {
 			builder.build(FidoFetch.getFido().getURL("/DOMBuilder/attributes.xml"));