sascha@58: package de.intevation.artifactdatabase;
sascha@58: 
sascha@58: import org.w3c.dom.Document;
sascha@58: 
sascha@58: import de.intevation.artifacts.Artifact;
sascha@58: import de.intevation.artifacts.CallContext;
sascha@58: import de.intevation.artifacts.ArtifactFactory;
sascha@58: 
sascha@58: import org.apache.log4j.Logger;
sascha@58: 
sascha@58: import java.io.IOException;
sascha@58: import java.io.OutputStream;
sascha@58: 
sascha@58: /**
sascha@58:  * @author Sascha L. Teichmann (sascha.teichmann@intevation.de)
sascha@58:  */
sascha@58: public class ProxyArtifact
sascha@58: extends      DefaultArtifact
sascha@58: {
sascha@58:     public static final Object REPLACE_PROXY = new Object();
sascha@58: 
sascha@58:     private static Logger logger = Logger.getLogger(ProxyArtifact.class);
sascha@58: 
sascha@58:     protected Artifact proxied;
sascha@58: 
sascha@58:     public ProxyArtifact() {
sascha@58:     }
sascha@58: 
sascha@58:     public ProxyArtifact(Artifact proxied) {
sascha@58:         this.proxied = proxied;
sascha@58:     }
sascha@58: 
sascha@58:     public Artifact getProxied() {
sascha@58:         return proxied;
sascha@58:     }
sascha@58: 
sascha@58:     public void setProxied(Artifact proxied) {
sascha@58:         this.proxied = proxied;
sascha@58:     }
sascha@58: 
sascha@58:     protected void checkReplacement(CallContext callContext) {
sascha@58:         Object replacement = callContext.getContextValue(REPLACE_PROXY);
sascha@58:         if (replacement instanceof Artifact) {
sascha@58:             setProxied((Artifact)replacement);
sascha@58:         }
sascha@58:     }
sascha@58: 
sascha@58:     public String hash() {
sascha@58:         return proxied != null
sascha@58:             ? proxied.hash()
sascha@58:             : super.hash();
sascha@58:     }
sascha@58: 
sascha@58:     public Document describe(Document data, CallContext context) {
sascha@58:         try {
sascha@58:             return proxied != null
sascha@58:                 ? proxied.describe(data, context)
sascha@58:                 : super.describe(data, context);
sascha@58:         }
sascha@58:         finally {
sascha@58:             checkReplacement(context);
sascha@58:         }
sascha@58:     }
sascha@58: 
sascha@58:     public Document advance(Document target, CallContext context) {
sascha@58:         try {
sascha@58:             return proxied != null
sascha@58:                 ? proxied.advance(target, context)
sascha@58:                 : super.advance(target, context);
sascha@58:         }
sascha@58:         finally {
sascha@58:             checkReplacement(context);
sascha@58:         }
sascha@58:     }
sascha@58: 
sascha@58:     public Document feed(Document target, CallContext context) {
sascha@58:         try {
sascha@58:             return proxied != null 
sascha@58:                 ? proxied.feed(target, context)
sascha@58:                 : super.feed(target, context);
sascha@58:         }
sascha@58:         finally {
sascha@58:             checkReplacement(context);
sascha@58:         }
sascha@58:     }
sascha@58: 
sascha@58:     public void out(
sascha@58:         Document     format,
sascha@58:         OutputStream out,
sascha@58:         CallContext  context
sascha@58:     )
sascha@58:     throws IOException
sascha@58:     {
sascha@58:         try {
sascha@58:             if (proxied != null) {
sascha@58:                 proxied.out(format, out, context);
sascha@58:             }
sascha@58:             else {
sascha@58:                 super.out(format, out, context);
sascha@58:             }
sascha@58:         }
sascha@58:         finally {
sascha@58:             checkReplacement(context);
sascha@58:         }
sascha@58:     }
sascha@58: 
sascha@58:     public void endOfLife(Object context) {
sascha@58:         if (proxied != null) {
sascha@58:             proxied.endOfLife(context);
sascha@58:         }
sascha@58:         else {
sascha@58:             super.endOfLife(context);
sascha@58:         }
sascha@58:     }
sascha@58: }
sascha@58: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8: