filterchain.java

一个java写的加密算法

/*
 * Copyright 2004-2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

package samples.xml.xslt;

import javax.xml.parsers.FactoryConfigurationError;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
 
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import org.xml.sax.XMLFilter;

import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.TransformerConfigurationException;

import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.SAXSource;
import javax.xml.transform.sax.SAXResult;

import javax.xml.transform.stream.StreamSource;
import javax.xml.transform.stream.StreamResult;

import java.io.*;

public class FilterChain
{
  public static void main (String argv [])
  {
    if (argv.length != 3) {
      System.err.println ("Usage: java FilterChain stylesheet1 stylesheet2 xmlfile");
      System.exit (1);
    }
  
    try {
      // Read the arguments
      File stylesheet1 = new File(argv[0]);
      File stylesheet2 = new File(argv[1]);
      File datafile    = new File(argv[2]);
      
      // Set up the input stream
      BufferedInputStream bis = new BufferedInputStream(new FileInputStream(datafile));
      InputSource input = new InputSource(bis);
        
      // Set up to read the input file
      SAXParserFactory spf = SAXParserFactory.newInstance();
      SAXParser parser = spf.newSAXParser();
      XMLReader reader = parser.getXMLReader();
    
      // Create the filters
      // --SAXTransformerFactory is an interface
      // --TransformerFactory is a concrete class
      // --TransformerFactory actually returns a SAXTransformerFactory instance
      // --We didn't care about that before, because we didn't use the
      // --SAXTransformerFactory extensions. But now we do, so we cast the result.
      SAXTransformerFactory stf =
        (SAXTransformerFactory) TransformerFactory.newInstance();
      XMLFilter filter1 = stf.newXMLFilter(new StreamSource(stylesheet1));
      XMLFilter filter2 = stf.newXMLFilter(new StreamSource(stylesheet2));

      // Wire the output of the reader to filter1
      // and the output of filter1 to filter2
      // --A filter is a kind of reader
      // --Setting the parent sets the input reader
      // --Since a filter is a reader, the "parent" could be another filter
      filter1.setParent(reader);
      filter2.setParent(filter1);

      // Set up the output stream
      StreamResult result = new StreamResult(System.out);
      
      // Set up the transformer to process the SAX events generated
      // by the last filter in the chain
      Transformer transformer = stf.newTransformer();
      SAXSource transformSource = new SAXSource(filter2, input);
      transformer.transform(transformSource, result);
    }
    catch (TransformerConfigurationException tce) {
      // Error generated by the parser
      System.out.println ("\n** Transformer Factory error");
      System.out.println("   " + tce.getMessage() );
      
      // Use the contained exception, if any
      Throwable x = tce;
      if (tce.getException() != null)
         x = tce.getException();
      x.printStackTrace();
    }
    catch (TransformerException te) {
      // Error generated by the parser
      System.out.println ("\n** Transformation error");
      System.out.println("   " + te.getMessage() );
      
      // Use the contained exception, if any
      Throwable x = te;
      if (te.getException() != null)
         x = te.getException();
      x.printStackTrace();
    }
    catch (SAXException sxe) {
      // Error generated by this application
      // (or a parser-initialization error)
      Exception  x = sxe;
      if (sxe.getException() != null)
         x = sxe.getException();
      x.printStackTrace();
    }
    catch (ParserConfigurationException pce) {
      // Parser with specified options can't be built
      pce.printStackTrace();
    }
    catch (IOException ioe) {
      // I/O error
      ioe.printStackTrace();
    }

  } // main

}