Simplify code in XmlPullParserFactory.

Since we're hard coding KXmlParser and KXmlSerializer
anyway, we might as well do it more directly.

Also add a trivial unit test for this method.

NOTE: This change preserves existing behaviour and doesn't
throw from #newInstance if the parser class couldn't be
found or instantiated. We instead throw from newPullParser or
newSerializer as appropriate.

Change-Id: Ic0c86e67691b8e662d95363bbe597d3abb7c3642

1 files changed, 25 insertions, 202 deletions

diff --git a/xml/src/main/java/org/xmlpull/v1/XmlPullParserFactory.java b/xml/src/main/java/org/xmlpull/v1/XmlPullParserFactory.java
index 4375a41..d08c342 100644
--- a/xml/src/main/java/org/xmlpull/v1/XmlPullParserFactory.java
+++ b/xml/src/main/java/org/xmlpull/v1/XmlPullParserFactory.java
@@ -3,28 +3,14 @@
 
 package org.xmlpull.v1;
 
-import java.io.InputStream;
-import java.util.ArrayList;
+import org.kxml2.io.KXmlParser;
+import org.kxml2.io.KXmlSerializer;
+
 import java.util.HashMap;
-import java.util.Iterator;
+import java.util.Map;
 
 /**
  * This class is used to create implementations of XML Pull Parser defined in XMPULL V1 API.
- * The name of actual factory class will be determined based on several parameters.
- * It works similar to JAXP but tailored to work in J2ME environments
- * (no access to system properties or file system) so name of parser class factory to use
- * and its class used for loading (no class loader - on J2ME no access to context class loaders)
- * must be passed explicitly. If no name of parser factory was passed (or is null)
- * it will try to find name by searching in CLASSPATH for
- * META-INF/services/org.xmlpull.v1.XmlPullParserFactory resource that should contain
- * a comma separated list of class names of factories or parsers to try (in order from
- * left to the right). If none found, it will throw an exception.
- *
- * <br /><strong>NOTE:</strong>In J2SE or J2EE environments, you may want to use
- * <code>newInstance(property, classLoaderCtx)</code>
- * where first argument is
- * <code>System.getProperty(XmlPullParserFactory.PROPERTY_NAME)</code>
- * and second is <code>Thread.getContextClassLoader().getClass()</code> .
  *
  * @see XmlPullParser
  *
@@ -33,40 +19,13 @@ import java.util.Iterator;
  */
 
 public class XmlPullParserFactory {
-    /** used as default class to server as context class in newInstance() */
-    final static Class referenceContextClass;
-
-    static {
-        XmlPullParserFactory f = new XmlPullParserFactory();
-        referenceContextClass = f.getClass();
-    }
-
-    /** Name of the system or midlet property that should be used for
-     a system property containing a comma separated list of factory
-     or parser class names (value:
-     org.xmlpull.v1.XmlPullParserFactory). */
-
-
+    /** Currently unused. */
+    // TODO: Deprecate or remove this field.
     public static final String PROPERTY_NAME =
         "org.xmlpull.v1.XmlPullParserFactory";
 
-    private static final String RESOURCE_NAME =
-        "/META-INF/services/" + PROPERTY_NAME;
-
-
-    // public static final String DEFAULT_PROPERTY =
-    //    "org.xmlpull.xpp3.XmlPullParser,org.kxml2.io.KXmlParser";
-
-
-    protected ArrayList parserClasses;
-    protected String classNamesLocation;
-
-    protected ArrayList serializerClasses;
-
-
     // features are kept there
-    protected HashMap features = new HashMap();
-
+    protected final HashMap<String, Boolean> features = new HashMap<String, Boolean>();
 
     /**
      * Protected constructor to be called by factory implementations.
@@ -100,7 +59,7 @@ public class XmlPullParserFactory {
      */
 
     public boolean getFeature (String name) {
-        Boolean value = (Boolean) features.get(name);
+        Boolean value = features.get(name);
         return value != null ? value.booleanValue() : false;
     }
 
@@ -161,40 +120,15 @@ public class XmlPullParserFactory {
      * using the currently configured factory features.
      *
      * @return A new instance of a XML Pull Parser.
-     * @throws XmlPullParserException if a parser cannot be created which satisfies the
-     * requested configuration.
      */
 
     public XmlPullParser newPullParser() throws XmlPullParserException {
-
-        if (parserClasses == null) throw new XmlPullParserException
-                ("Factory initialization was incomplete - has not tried "+classNamesLocation);
-
-        if (parserClasses.size() == 0) throw new XmlPullParserException
-                ("No valid parser classes found in "+classNamesLocation);
-
-        final StringBuilder issues = new StringBuilder();
-
-        for (int i = 0; i < parserClasses.size(); i++) {
-            final Class ppClass = (Class) parserClasses.get(i);
-            try {
-                final XmlPullParser pp = (XmlPullParser) ppClass.newInstance();
-
-                for (Iterator iter = features.keySet().iterator(); iter.hasNext(); ) {
-                    final String key = (String) iter.next();
-                    final Boolean value = (Boolean) features.get(key);
-                    if(value != null && value.booleanValue()) {
-                        pp.setFeature(key, true);
-                    }
-                }
-                return pp;
-
-            } catch(Exception ex) {
-                issues.append (ppClass.getName () + ": "+ ex.toString ()+"; ");
-            }
+        final XmlPullParser pp = new KXmlParser();
+        for (Map.Entry<String, Boolean> entry : features.entrySet()) {
+            pp.setFeature(entry.getKey(), entry.getValue());
         }
 
-        throw new XmlPullParserException ("could not create parser: "+issues);
+        return pp;
     }
 
 
@@ -209,137 +143,26 @@ public class XmlPullParserFactory {
      */
 
     public XmlSerializer newSerializer() throws XmlPullParserException {
-
-        if (serializerClasses == null) {
-            throw new XmlPullParserException
-                ("Factory initialization incomplete - has not tried "+classNamesLocation);
-        }
-        if(serializerClasses.size() == 0) {
-            throw new XmlPullParserException
-                ("No valid serializer classes found in "+classNamesLocation);
-        }
-
-        final StringBuilder issues = new StringBuilder ();
-
-        for (int i = 0; i < serializerClasses.size (); i++) {
-            final Class ppClass = (Class) serializerClasses.get(i);
-            try {
-                final XmlSerializer ser = (XmlSerializer) ppClass.newInstance();
-
-                return ser;
-
-            } catch(Exception ex) {
-                issues.append (ppClass.getName () + ": "+ ex.toString ()+"; ");
-            }
-        }
-
-        throw new XmlPullParserException ("could not create serializer: "+issues);
+        return new KXmlSerializer();
     }
 
     /**
-     * Create a new instance of a PullParserFactory that can be used
-     * to create XML pull parsers (see class description for more
-     * details).
-     *
-     * @return a new instance of a PullParserFactory, as returned by newInstance (null, null);
+     * Creates a new instance of a PullParserFactory that can be used
+     * to create XML pull parsers. The factory will always return instances
+     * of {@link KXmlParser} and {@link KXmlSerializer}.
      */
     public static XmlPullParserFactory newInstance () throws XmlPullParserException {
-        return newInstance(null, null);
+        return new XmlPullParserFactory();
     }
 
-    public static XmlPullParserFactory newInstance (String classNames, Class context)
+    /**
+     * Creates a factory that always returns instances of of {@link KXmlParser} and
+     * {@link KXmlSerializer}. This <b>does not</b> support factories capable of
+     * creating arbitrary parser and serializer implementations. Both arguments to this
+     * method are unused.
+     */
+    public static XmlPullParserFactory newInstance (String unused, Class unused2)
         throws XmlPullParserException {
-
-        /*
-        if (context == null) {
-            //NOTE: make sure context uses the same class loader as API classes
-            //      this is the best we can do without having access to context classloader in J2ME
-            //      if API is in the same classloader as implementation then this will work
-            context = referenceContextClass;
-        }
-
-        String  classNamesLocation = null;
-
-        if (classNames == null || classNames.length() == 0 || "DEFAULT".equals(classNames)) {
-            try {
-                InputStream is = context.getResourceAsStream (RESOURCE_NAME);
-
-                if (is == null) throw new XmlPullParserException
-                        ("resource not found: "+RESOURCE_NAME
-                             +" make sure that parser implementing XmlPull API is available");
-                final StringBuilder sb = new StringBuilder();
-
-                while (true) {
-                    final int ch = is.read();
-                    if (ch < 0) break;
-                    else if (ch > ' ')
-                        sb.append((char) ch);
-                }
-                is.close ();
-
-                classNames = sb.toString ();
-            }
-            catch (Exception e) {
-                throw new XmlPullParserException (null, null, e);
-            }
-            classNamesLocation = "resource "+RESOURCE_NAME+" that contained '"+classNames+"'";
-        } else {
-            classNamesLocation =
-                "parameter classNames to newInstance() that contained '"+classNames+"'";
-        }
-        */
-        classNames = "org.kxml2.io.KXmlParser,org.kxml2.io.KXmlSerializer";
-
-        XmlPullParserFactory factory = null;
-        final ArrayList parserClasses = new ArrayList();
-        final ArrayList serializerClasses = new ArrayList();
-        int pos = 0;
-
-        while (pos < classNames.length ()) {
-            int cut = classNames.indexOf (',', pos);
-
-            if (cut == -1) cut = classNames.length ();
-            final String name = classNames.substring (pos, cut);
-
-            Class candidate = null;
-            Object instance = null;
-
-            try {
-                candidate = Class.forName (name);
-                // necessary because of J2ME .class issue
-                instance = candidate.newInstance ();
-            }
-            catch (Exception e) {}
-
-            if (candidate != null) {
-                boolean recognized = false;
-                if (instance instanceof XmlPullParser) {
-                    parserClasses.add(candidate);
-                    recognized = true;
-                }
-                if (instance instanceof XmlSerializer) {
-                    serializerClasses.add(candidate);
-                    recognized = true;
-                }
-                if (instance instanceof XmlPullParserFactory) {
-                    if (factory == null) {
-                        factory = (XmlPullParserFactory) instance;
-                    }
-                    recognized = true;
-                }
-                if (!recognized) {
-                    throw new XmlPullParserException ("incompatible class: "+name);
-                }
-            }
-            pos = cut + 1;
-        }
-
-        if (factory == null) {
-            factory = new XmlPullParserFactory ();
-        }
-        factory.parserClasses = parserClasses;
-        factory.serializerClasses = serializerClasses;
-        factory.classNamesLocation = "org.kxml2.io.kXmlParser,org.kxml2.io.KXmlSerializer";
-        return factory;
+        return newInstance();
     }
 }