mystreamfilter.java

java 的关于web serive教程

package filter;

import java.io.*;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import javax.xml.stream.*;
import javax.xml.stream.events.* ;
import java.util.Date;
import javax.xml.namespace.QName;

/**
 * MyStreamFilter sample is used to demonstrates the use
 * of STAX stream filter api's. This filter accepts only 
 * StartElement and EndElement events and filters out rest of
 * the events.
 */

public class MyStreamFilter implements javax.xml.stream.StreamFilter{
    
    private static String filename = null;
    
    
    private static void printUsage() {
        System.out.println("usage: java -classpath MyStreamFilter -f <xmlfile>");
    }
    
    /**
     * 
     * @param args 
     * @throws Exception 
     */
    public static void main(String[] args) throws Exception {
        
        
        try {
            if(args[0].equals("-f")){
                filename = args[1];
            }
            else{
                printUsage() ;
            }
        } catch (ArrayIndexOutOfBoundsException aioobe){
            printUsage();
            System.exit(0);
        } catch (Exception ex){
            printUsage();
            ex.printStackTrace() ;
        }
        
        
        XMLInputFactory xmlif = null ;
        try{
            xmlif = XMLInputFactory.newInstance();
            xmlif.setProperty(XMLInputFactory.IS_REPLACING_ENTITY_REFERENCES,Boolean.TRUE);
            xmlif.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES,Boolean.FALSE);
            xmlif.setProperty(XMLInputFactory.IS_NAMESPACE_AWARE , Boolean.TRUE);
            xmlif.setProperty(XMLInputFactory.IS_COALESCING , Boolean.TRUE);
        }catch(Exception ex){
            ex.printStackTrace();
        }
        System.out.println("FACTORY: " + xmlif);
        System.out.println("filename = "+ filename);
        
        
        
        try{
            
            FileInputStream fis = new FileInputStream(filename);
            
            XMLStreamReader xmlr = xmlif.createFilteredReader(xmlif.createXMLStreamReader(fis), new MyStreamFilter());
            
            int eventType = xmlr.getEventType();
            printEventType(eventType);
            while(xmlr.hasNext()){
                eventType = xmlr.next();
                printEventType(eventType);
                printName(xmlr,eventType);
                printText(xmlr);
                if(xmlr.isStartElement()){
                    printAttributes(xmlr);
                }
                printPIData(xmlr);
                System.out.println("-----------------------------");
            }
            
        }catch(Exception ex){
            ex.printStackTrace();
        }
        
    }
    
    /**
     * @param eventType
     * @return
     */
    public final static String getEventTypeString(int eventType) {
        switch (eventType){
            case XMLEvent.START_ELEMENT:
                return "START_ELEMENT";
            case XMLEvent.END_ELEMENT:
                return "END_ELEMENT";
            case XMLEvent.PROCESSING_INSTRUCTION:
                return "PROCESSING_INSTRUCTION";
            case XMLEvent.CHARACTERS:
                return "CHARACTERS";
            case XMLEvent.COMMENT:
                return "COMMENT";
            case XMLEvent.START_DOCUMENT:
                return "START_DOCUMENT";
            case XMLEvent.END_DOCUMENT:
                return "END_DOCUMENT";
            case XMLEvent.ENTITY_REFERENCE:
                return "ENTITY_REFERENCE";
            case XMLEvent.ATTRIBUTE:
                return "ATTRIBUTE";
            case XMLEvent.DTD:
                return "DTD";
            case XMLEvent.CDATA:
                return "CDATA";
        }
        return "UNKNOWN_EVENT_TYPE";
    }
    
    private static void printEventType(int eventType) {
        System.out.print("EVENT TYPE("+eventType+"):");
        System.out.println(getEventTypeString(eventType));
    }
    
    private static void printName(XMLStreamReader xmlr,int eventType){
        if(xmlr.hasName()){
            System.out.println("HAS NAME: " + xmlr.getLocalName());
        } else {
            System.out.println("HAS NO NAME");
        }
    }
    
    private static void printText(XMLStreamReader xmlr){
        if(xmlr.hasText()){
            System.out.println("HAS TEXT: " + xmlr.getText());
        } else {
            System.out.println("HAS NO TEXT");
        }
    }
    
    private static void printPIData(XMLStreamReader xmlr){
        if (xmlr.getEventType() == XMLEvent.PROCESSING_INSTRUCTION){
            System.out.println(" PI target = " + xmlr.getPITarget() ) ;
            System.out.println(" PI Data = " + xmlr.getPIData() ) ;
        }
    }
    
    private static void printAttributes(XMLStreamReader xmlr){
        if(xmlr.getAttributeCount() > 0){
            System.out.println("\nHAS ATTRIBUTES: ");
            int count = xmlr.getAttributeCount() ;
            for(int i = 0 ; i < count ; i++) {
                
                QName name = xmlr.getAttributeName(i) ;
                String namespace = xmlr.getAttributeNamespace(i) ;
                String  type = xmlr.getAttributeType(i) ;
                String prefix = xmlr.getAttributePrefix(i) ;
                String value = xmlr.getAttributeValue(i) ;
                
                System.out.println("ATTRIBUTE-PREFIX: " + prefix );
                System.out.println("ATTRIBUTE-NAMESP: " + namespace );
                System.out.println("ATTRIBUTE-NAME:   " + name.toString() );
                System.out.println("ATTRIBUTE-VALUE:  " + value );
                System.out.println("ATTRIBUTE-TYPE:  " + type );
                System.out.println();
                
            }
            
        } else {
            System.out.println("HAS NO ATTRIBUTES");
        }
    }
    
    /**
     * Accept only StartElement and EndElement events,Filters out rest of the events.
     * @param reader 
     * @return 
     */
    public boolean accept(XMLStreamReader reader) {
        if(!reader.isStartElement() && !reader.isEndElement())
            return false;
        else
            return true;
    }
}