Created a simple extensible parser class to take care of common

character data gathering and file parsing machinations.


git-svn-id: https://samskivert.googlecode.com/svn/trunk@357 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/samskivert/src/java/com/samskivert/xml/SimpleParser.java

@@ -0,0 +1,103 @@
+//
+// $Id: SimpleParser.java,v 1.1 2001/10/15 23:46:02 shaper Exp $
+
+package com.samskivert.xml;
+
+import java.io.*;
+import javax.xml.parsers.ParserConfigurationException;
+
+import org.xml.sax.*;
+import org.xml.sax.helpers.DefaultHandler;
+
+import com.samskivert.Log;
+
+/**
+ * The simple parser class provides an extensible object that is
+ * intended to simplify the task of writing an object to parse a
+ * particular XML file.
+ */
+public class SimpleParser extends DefaultHandler
+{
+    // documentation inherited
+    public void characters (char ch[], int start, int length)
+    {
+  	_chars.append(ch, start, length);
+    }
+
+    // documentation inherited
+    public void endElement (String uri, String localName, String qName)
+    {
+	finishElement(uri, localName, qName, _chars.toString().trim());
+        _chars = new StringBuffer();
+    }
+
+    /**
+     * Parse the given file.
+     *
+     * @param fname the file to parse.
+     *
+     * @exception IOException thrown if an error occurs while parsing
+     * the file.
+     */
+    public void parseFile (String fname) throws IOException
+    {
+        _fname = fname;
+
+	try {
+            InputStream is = getInputStream(fname);
+
+            // read the XML input stream and construct the scene object
+            _chars = new StringBuffer();
+	    XMLUtil.parse(this, is);
+
+        } catch (ParserConfigurationException pce) {
+  	    throw new IOException(pce.toString());
+
+	} catch (SAXException saxe) {
+	    throw new IOException(saxe.toString());
+	}
+    }
+
+    /**
+     * Called when parsing an element is finished and its data is
+     * fully available.  Essentially the same as {@link #endElement}
+     * excepting that the final complete character data is provided as
+     * a parameter and is conveniently trimmed of any extraneous white
+     * space.
+     */
+    protected void finishElement (
+        String uri, String localName, String qName, String data)
+    {
+        // nothing for now
+    }
+
+    /**
+     * Returns an input stream to read data from the given file name.
+     */
+    protected InputStream getInputStream (String fname)
+        throws IOException
+    {
+        FileInputStream fis = new FileInputStream(fname);
+        return new BufferedInputStream(fis);
+    }
+
+    /**
+     * Parse the given string as an integer and return the integer
+     * value, or -1 if the string is malformed.
+     */
+    protected int parseInt (String val)
+    {
+        try {
+            return (val == null) ? -1 : Integer.parseInt(val);
+        } catch (NumberFormatException nfe) {
+            Log.warning("Malformed integer value [val=" + val + "].");
+            return -1;
+        }
+    }
+
+    /** The file being parsed. */
+    protected String _fname;
+
+    /** The character data gathered while parsing. */
+    protected StringBuffer _chars;
+}