Move JAXP stuff into a new utility class.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@272556 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/helper/ProjectHelperImpl.java

@@ -63,15 +63,11 @@ import java.util.Locale;
 import org.xml.sax.Locator;
 import org.xml.sax.InputSource;
 import org.xml.sax.HandlerBase;
-import org.xml.sax.SAXParseException;
 import org.xml.sax.SAXException;
+import org.xml.sax.SAXParseException;
 import org.xml.sax.DocumentHandler;
 import org.xml.sax.AttributeList;
 import org.xml.sax.helpers.XMLReaderAdapter;
-import javax.xml.parsers.SAXParserFactory;
-import javax.xml.parsers.SAXParser;
-import javax.xml.parsers.ParserConfigurationException;
-import javax.xml.parsers.FactoryConfigurationError;
 import org.apache.tools.ant.ProjectHelper;
 import org.apache.tools.ant.UnknownElement;
 import org.apache.tools.ant.Project;
@@ -83,6 +79,7 @@ import org.apache.tools.ant.IntrospectionHelper;
 import org.apache.tools.ant.TaskContainer;
 import org.apache.tools.ant.Location;
 import org.apache.tools.ant.TaskAdapter;
+import org.apache.tools.ant.util.JAXPUtils;
 
 /**
  * Original helper.
@@ -91,12 +88,6 @@ import org.apache.tools.ant.TaskAdapter;
  */
 public class ProjectHelperImpl extends ProjectHelper {
 
-    /**
-     * Parser factory to use to create parsers.
-     * @see #getParserFactory
-     */
-    private static SAXParserFactory parserFactory = null;
-
     /**
      * SAX 1 style parser used to parse the given file. This may
      * in fact be a SAX 2 XMLReader wrapped in an XMLReaderAdapter.
@@ -139,11 +130,10 @@ public class ProjectHelperImpl extends ProjectHelper {
         buildFileParent = new File(this.buildFile.getParent());
 
         try {
-            SAXParser saxParser = getParserFactory().newSAXParser();
             try {
-                parser = saxParser.getParser();
-            } catch (SAXException exc) {
-                parser = new XMLReaderAdapter(saxParser.getXMLReader());
+                parser = JAXPUtils.getParser();
+            } catch (BuildException e) {
+                parser = new XMLReaderAdapter(JAXPUtils.getXMLReader());
             }
 
 
@@ -163,11 +153,6 @@ public class ProjectHelperImpl extends ProjectHelper {
             parser.setErrorHandler(hb);
             parser.setDTDHandler(hb);
             parser.parse(inputSource);
-        } catch (ParserConfigurationException exc) {
-            throw new BuildException("Parser has not been configured correctly", exc);
-        } catch (FactoryConfigurationError e) {
-            throw new BuildException("XML parser has not been configured " 
-                + "correctly: " + e.getMessage(), e);
         } catch (SAXParseException exc) {
             Location location =
                 new Location(buildFile.toString(), exc.getLineNumber(),
@@ -1151,21 +1136,6 @@ public class ProjectHelperImpl extends ProjectHelper {
         }
     }
 
-    /**
-     * Returns the parser factory to use. Only one parser
-     * factory is ever created by this method (multi-threading
-     * issues aside) and is then cached for future use.
-     *
-     * @return a SAXParserFactory to use within this class
-     */
-    private static SAXParserFactory getParserFactory() {
-        if (parserFactory == null) {
-            parserFactory = SAXParserFactory.newInstance();
-        }
-
-        return parserFactory;
-    }
-
     /**
      * Scans an attribute list for the <code>id</code> attribute and
      * stores a reference to the target object in the project if an

src/main/org/apache/tools/ant/taskdefs/optional/XMLValidateTask.java

@@ -64,10 +64,6 @@ import java.net.URL;
 import java.util.Vector;
 import java.util.Hashtable;
 import java.util.Enumeration;
-import javax.xml.parsers.SAXParserFactory;
-import javax.xml.parsers.SAXParser;
-import javax.xml.parsers.ParserConfigurationException;
-import javax.xml.parsers.FactoryConfigurationError;
 import org.apache.tools.ant.AntClassLoader;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.DirectoryScanner;
@@ -78,6 +74,7 @@ import org.apache.tools.ant.types.Path;
 import org.apache.tools.ant.types.Reference;
 import org.apache.tools.ant.types.XMLCatalog;
 import org.apache.tools.ant.types.DTDLocation;
+import org.apache.tools.ant.util.JAXPUtils;
 import org.xml.sax.XMLReader;
 import org.xml.sax.EntityResolver;
 import org.xml.sax.Parser;
@@ -96,12 +93,6 @@ import org.xml.sax.helpers.ParserAdapter;
  */
 public class XMLValidateTask extends Task {
 
-    /**
-     * Parser factory to use to create parsers.
-     * @see #getParserFactory
-     */
-    private static SAXParserFactory parserFactory = null;
-
     protected static String INIT_FAILED_MSG = 
         "Could not start xml validation: ";
 
@@ -294,20 +285,10 @@ public class XMLValidateTask extends Task {
 
         Object reader = null;
         if (readerClassName == null) {
-            // use JAXP
             try {
-                SAXParser saxParser = getParserFactory().newSAXParser();
-                try {
-                    reader = saxParser.getXMLReader();
-                } catch (SAXException exc) {
-                    reader = saxParser.getParser();
-                }
-            } catch (ParserConfigurationException e) {
-                throw new BuildException(INIT_FAILED_MSG + e.getMessage(), 
-                                         e, getLocation());
-            } catch (SAXException e) {
-                throw new BuildException(INIT_FAILED_MSG + e.getMessage(), 
-                                         e, getLocation());
+                reader = JAXPUtils.getXMLReader();
+            } catch (BuildException exc) {
+                reader = JAXPUtils.getParser();
             }
         } else {
         
@@ -372,21 +353,6 @@ public class XMLValidateTask extends Task {
         }
     }
 
-    /**
-     * Returns the parser factory to use. Only one parser
-     * factory is ever created by this method (multi-threading
-     * issues aside) and is then cached for future use.
-     *
-     * @return a SAXParserFactory to use within this class
-     */
-    private static SAXParserFactory getParserFactory() {
-        if (parserFactory == null) {
-            parserFactory = SAXParserFactory.newInstance();
-        }
-
-        return parserFactory;
-    }
-
     /*
      * set a feature on the parser.
      * TODO: find a way to set any feature from build.xml

src/main/org/apache/tools/ant/util/JAXPUtils.java

@@ -0,0 +1,183 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2002 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Ant", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.tools.ant.util;
+
+import org.apache.tools.ant.BuildException;
+
+import org.xml.sax.Parser;
+import org.xml.sax.SAXException;
+import org.xml.sax.XMLReader;
+
+import javax.xml.parsers.SAXParserFactory;
+import javax.xml.parsers.SAXParser;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.parsers.FactoryConfigurationError;
+
+/**
+ * Collection of helper methods that retrieve a ParserFactory or
+ * Parsers and Readers.
+ *
+ * <p>This class will create only a single factory instance.</p>
+ *
+ * @author <a href="mailto:stefan.bodewig@epost.de">Stefan Bodewig</a>
+ *
+ * @since Ant 1.5
+ */
+public class JAXPUtils {
+
+    /**
+     * Parser factory to use to create parsers.
+     * @see #getParserFactory
+     *
+     * @since Ant 1.5
+     */
+    private static SAXParserFactory parserFactory = null;
+
+    /**
+     * Returns the parser factory to use. Only one parser factory is
+     * ever created by this method and is then cached for future use.
+     *
+     * @return a SAXParserFactory to use
+     *
+     * @since Ant 1.5
+     */
+    public synchronized static SAXParserFactory getParserFactory() 
+        throws BuildException {
+
+        if (parserFactory == null) {
+            parserFactory = newParserFactory();
+        }
+        return parserFactory;
+    }
+
+    /**
+     * Returns a new  parser factory instance.
+     *
+     * @since Ant 1.5
+     */
+    public static SAXParserFactory newParserFactory() throws BuildException {
+
+        try {
+            return SAXParserFactory.newInstance();
+        } catch (FactoryConfigurationError e) {
+            throw new BuildException("XML parser factory has not been "
+                                     + "configured correctly: " 
+                                     + e.getMessage(), e);
+        }
+    }
+
+    /**
+     * Returns a newly created SAX 1 Parser, using the default parser
+     * factory.
+     *
+     * @return a SAX 1 Parser.
+     * @see #getParserFactory
+     * @since Ant 1.5
+     */
+    public static Parser getParser() throws BuildException {
+        try {
+            return newSAXParser().getParser();
+        } catch (SAXException e) {
+            throw convertToBuildException(e);
+        }
+    }
+
+    /**
+     * Returns a newly created SAX 2 XMLReader, using the default parser
+     * factory.
+     *
+     * @return a SAX 2 XMLReader.
+     * @see #getParserFactory
+     * @since Ant 1.5
+     */
+    public static XMLReader getXMLReader() throws BuildException {
+        try {
+            return newSAXParser().getXMLReader();
+        } catch (SAXException e) {
+            throw convertToBuildException(e);
+        }
+    }
+
+    /**
+     * @return a new SAXParser instance as helper for getParser and
+     * getXMLReader.
+     *
+     * @since Ant 1.5
+     */
+    private static SAXParser newSAXParser() throws BuildException {
+        try {
+            return getParserFactory().newSAXParser();
+        } catch (ParserConfigurationException e) {
+            throw new BuildException("Cannot create parser for the given "
+                                     + "configuration: " + e.getMessage(), e);
+        } catch (SAXException e) {
+            throw convertToBuildException(e);
+        }
+    }
+
+    /**
+     * Translate a SAXException into a BuildException
+     *
+     * @since Ant 1.5
+     */
+    private static BuildException convertToBuildException(SAXException e) {
+        Exception nested = e.getException();
+        if (nested != null) {
+            return new BuildException(nested);
+        } else {
+            return new BuildException(e);
+        }
+    }
+
+}