echo09.java

xml教程,Understanding XML and the Java XML APIs

/*
 * @(#)Echo09.java	1.5 99/02/09
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.io.*;

import org.xml.sax.*;
import org.xml.sax.helpers.ParserFactory;

import com.sun.xml.parser.Resolver;


public class Echo09 extends HandlerBase
{
    public static void main (String argv [])
    throws IOException
    {
        InputSource	input;

        if (argv.length != 1) {
            System.err.println ("Usage: cmd filename");
            System.exit (1);
        }

        try {
            // Set up output stream
            out = new OutputStreamWriter (System.out, "UTF8");

            // Turn the filename into an XML input source
            input = Resolver.createInputSource (new File (argv [0]));

            // Get an instance of the non-validating parser.
            Parser parser;
            parser = ParserFactory.makeParser ("com.sun.xml.parser.Parser");
            parser.setDocumentHandler ( new Echo09() );

            // Set the new error handler
            parser.setErrorHandler ( new MyErrorHandler () );

            // Parse the input
            parser.parse (input);

        } catch (SAXParseException err) {
            System.out.println ("** Parsing error" 
                + ", line " + err.getLineNumber ()
                + ", uri " + err.getSystemId ());
            System.out.println("   " + err.getMessage ());

            // Unpack the delivered exception to get the exception it contains
            Exception	x = err;
            if (err.getException () != null)
                x = err.getException ();
            x.printStackTrace ();

        } catch (SAXException e) {
            Exception	x = e;
            if (e.getException () != null)
                x = e.getException ();
            x.printStackTrace ();

        } catch (Throwable t) {
            t.printStackTrace ();
        }

        System.exit (0);
    }

    static class MyErrorHandler extends HandlerBase
    {
      // treat validation errors as fatal
        public void error (SAXParseException e)
        throws SAXParseException
        {
            throw e;
        }

        // dump warnings too
        public void warning (SAXParseException err)
        throws SAXParseException
        {
            System.out.println ("** Warning" 
                + ", line " + err.getLineNumber ()
                + ", uri " + err.getSystemId ());
            System.out.println("   " + err.getMessage ());
        }
    }


    static private Writer	out;
    private String indentString = "    "; // Amount to indent
    private int indentLevel = 0;

    //===========================================================
    // SAX DocumentHandler methods
    //===========================================================

    public void setDocumentLocator (Locator l)
    {
        // Save this to resolve relative URIs or to give diagnostics.
        try {
          out.write ("LOCATOR");
          out.write ("\n SYS ID: " + l.getSystemId() );
          out.flush ();
        } catch (IOException e) {
            // Ignore errors
        }
    }

    public void startDocument ()
    throws SAXException
    {
        nl();
        nl(); 
        emit ("START DOCUMENT");
        nl(); 
        emit ("<?xml version='1.0' encoding='UTF-8'?>");
    }

    public void endDocument ()
    throws SAXException
    {
        nl(); emit ("END DOCUMENT");
        try {
            nl();
            out.flush ();
        } catch (IOException e) {
            throw new SAXException ("I/O error", e);
        }
    }

    public void startElement (String name, AttributeList attrs)
    throws SAXException
    {
        indentLevel++;
        nl(); emit ("ELEMENT: ");
        emit ("<"+name);
        if (attrs != null) {
            for (int i = 0; i < attrs.getLength (); i++) {
                nl(); 
                emit("   ATTR: ");
                emit (attrs.getName (i));
                emit ("\t\"");
                emit (attrs.getValue (i));
                emit ("\"");
            }
        }
        if (attrs.getLength() > 0) nl();
        emit (">");
    }

    public void endElement (String name)
    throws SAXException
    {
        nl(); 
        emit ("END_ELM: ");
        emit ("</"+name+">");
        indentLevel--;
    }

    public void characters (char buf [], int offset, int len)
    throws SAXException
    {
        nl(); emit ("CHARS:   ");
        String s = new String(buf, offset, len);
        if (!s.trim().equals("")) emit (s);
    }

    public void ignorableWhitespace (char buf [], int offset, int len)
    throws SAXException
    {
        // Ignore it
    }
    public void processingInstruction (String target, String data)
    throws SAXException
    {
        nl(); 
        emit ("PROCESS: ");
        emit ("<?"+target+" "+data+"?>");
    }

    //===========================================================
    // Helpers ... 
    //===========================================================

    // Wrap I/O exceptions in SAX exceptions, to
    // suit handler signature requirements
    private void emit (String s)
    throws SAXException
    {
        try {
            out.write (s);
            out.flush ();
        } catch (IOException e) {
            throw new SAXException ("I/O error", e);
        }
    }

    // Start a new line
    // and indent the next line appropriately
    private void nl ()
    throws SAXException
    {
        String lineEnd =  System.getProperty("line.separator");
        try {
            out.write (lineEnd);
            for (int i=0; i < indentLevel; i++) out.write(indentString);
        } catch (IOException e) {
            throw new SAXException ("I/O error", e);
        }
    }
}