hashmapper.java

JiBX是一个为Java提供的XML数据绑定框架。它可以和现存的类一起运行

package example21;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.jibx.runtime.IAliasable;
import org.jibx.runtime.IMarshallable;
import org.jibx.runtime.IMarshaller;
import org.jibx.runtime.IMarshallingContext;
import org.jibx.runtime.IUnmarshaller;
import org.jibx.runtime.IUnmarshallingContext;
import org.jibx.runtime.JiBXException;
import org.jibx.runtime.impl.MarshallingContext;
import org.jibx.runtime.impl.UnmarshallingContext;

public class HashMapper implements IMarshaller, IUnmarshaller, IAliasable
{
    private static final String SIZE_ATTRIBUTE_NAME = "size";
    private static final String ENTRY_ELEMENT_NAME = "entry";
    private static final String KEY_ATTRIBUTE_NAME = "key";
    private static final int DEFAULT_SIZE = 10;
    
    private String m_uri;
    private int m_index;
    private String m_name;
    
    public HashMapper() {
        m_uri = null;
        m_index = 0;
        m_name = "hashmap";
    }
    
    public HashMapper(String uri, int index, String name) {
        m_uri = uri;
        m_index = index;
        m_name = name;
    }
    
    /* (non-Javadoc)
     * @see org.jibx.runtime.IMarshaller#isExtension(int)
     */
    
    public boolean isExtension(int index) {
        return false;
    }

    /* (non-Javadoc)
     * @see org.jibx.runtime.IMarshaller#marshal(java.lang.Object,
     *  org.jibx.runtime.IMarshallingContext)
     */
    
    public void marshal(Object obj, IMarshallingContext ictx)
        throws JiBXException {
        
        // make sure the parameters are as expected
        if (!(obj instanceof HashMap)) {
            throw new JiBXException("Invalid object type for marshaller");
        } else if (!(ictx instanceof MarshallingContext)) {
            throw new JiBXException("Invalid object type for marshaller");
        } else {
            
            // start by generating start tag for container
            MarshallingContext ctx = (MarshallingContext)ictx;
            HashMap map = (HashMap)obj;
            ctx.startTagAttributes(m_index, m_name).
                attribute(m_index, SIZE_ATTRIBUTE_NAME, map.size()).
                closeStartContent();
            
            // loop through all entries in hashmap
            Iterator iter = map.entrySet().iterator();
            while (iter.hasNext()) {
                Map.Entry entry = (Map.Entry)iter.next();
                ctx.startTagAttributes(m_index, ENTRY_ELEMENT_NAME);
                if (entry.getKey() != null) {
                    ctx.attribute(m_index, KEY_ATTRIBUTE_NAME,
                        entry.getKey().toString());
                }
                ctx.closeStartContent();
                if (entry.getValue() instanceof IMarshallable) {
                    ((IMarshallable)entry.getValue()).marshal(ctx);
                    ctx.endTag(m_index, ENTRY_ELEMENT_NAME);
                } else {
                    throw new JiBXException("Mapped value is not marshallable");
                }
            }
            
            // finish with end tag for container element
            ctx.endTag(m_index, m_name);
        }
    }

    /* (non-Javadoc)
     * @see org.jibx.runtime.IUnmarshaller#isPresent(org.jibx.runtime.IUnmarshallingContext)
     */
     
    public boolean isPresent(IUnmarshallingContext ctx) throws JiBXException {
        return ctx.isAt(m_uri, m_name);
    }

    /* (non-Javadoc)
     * @see org.jibx.runtime.IUnmarshaller#unmarshal(java.lang.Object,
     *  org.jibx.runtime.IUnmarshallingContext)
     */
     
    public Object unmarshal(Object obj, IUnmarshallingContext ictx)
        throws JiBXException {
        
        // make sure we're at the appropriate start tag
        UnmarshallingContext ctx = (UnmarshallingContext)ictx;
        if (!ctx.isAt(m_uri, m_name)) {
            ctx.throwStartTagNameError(m_uri, m_name);
        }
        
        // create new hashmap if needed
        int size = ctx.attributeInt(m_uri, SIZE_ATTRIBUTE_NAME, DEFAULT_SIZE);
        HashMap map = (HashMap)obj;
        if (map == null) {
            map = new HashMap(size);
        }
        
        // process all entries present in document
        ctx.parsePastStartTag(m_uri, m_name);
        while (ctx.isAt(m_uri, ENTRY_ELEMENT_NAME)) {
            Object key = ctx.attributeText(m_uri, KEY_ATTRIBUTE_NAME, null);
            ctx.parsePastStartTag(m_uri, ENTRY_ELEMENT_NAME);
            Object value = ctx.unmarshalElement();
            map.put(key, value);
            ctx.parsePastEndTag(m_uri, ENTRY_ELEMENT_NAME);
        }
        ctx.parsePastEndTag(m_uri, m_name);
        return map;
    }
}