AbstractUploadAgentBuilder.java

/* ButtonUploadAgent.java

	Purpose:
		
	Description:
		
	History:
		Jun 19, 2012 Created by pao

Copyright (C) 2011 Potix Corporation. All Rights Reserved.
*/
package org.zkoss.zats.mimic.impl.operation;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.eclipse.jetty.util.IO;
import org.zkoss.lang.Strings;
import org.zkoss.zats.common.util.MultiPartOutputStream;
import org.zkoss.zats.mimic.AgentException;
import org.zkoss.zats.mimic.ComponentAgent;
import org.zkoss.zats.mimic.impl.ClientCtrl;
import org.zkoss.zats.mimic.impl.EventDataManager;
import org.zkoss.zats.mimic.impl.OperationAgentBuilder;
import org.zkoss.zats.mimic.impl.Util;
import org.zkoss.zats.mimic.operation.UploadAgent;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.event.Event;
import org.zkoss.zk.ui.sys.DesktopCtrl;

/**
 * The abstract builder of upload agent.
 * @author pao
 * @since 1.1.0
 */
public abstract class AbstractUploadAgentBuilder implements OperationAgentBuilder<ComponentAgent, UploadAgent> {
	private final static Logger logger = Logger.getLogger(AbstractUploadAgentBuilder.class.getName());

	public Class<UploadAgent> getOperationClass() {
		return UploadAgent.class;
	}

	abstract class AbstractUploadAgentImpl extends AgentDelegator<ComponentAgent> implements UploadAgent {

		private HttpURLConnection conn;
		private MultiPartOutputStream multipartStream;
		private boolean isMultiple;

		public AbstractUploadAgentImpl(ComponentAgent target) {
			super(target);
		}

		public void upload(File file, String contentType) {
			if (file == null)
				throw new NullPointerException("file can't be null.");

			InputStream is = null;
			try {
				is = new BufferedInputStream(new FileInputStream(file));
				upload(file.getName(), is, contentType);
			} catch (IOException e) {
				throw new AgentException(e.getMessage(), e);
			} finally {
				Util.close(is);
			}
		}
		
		protected abstract String getUploadFlag();

		public void upload(String fileName, InputStream content, String contentType) {
			if (fileName == null)
				throw new NullPointerException("file name can't be null.");
			if (content == null)
				throw new NullPointerException("content stream can't be null.");

			// first time upload
			if (multipartStream == null) {

				// fetch and check upload flag
				String flag = getUploadFlag();
				if (flag == null || flag.length() == 0)
					throw new AgentException("upload feature doesn't turn on.");
				else {
					Map<String, String> attr = new HashMap<String, String>();
					for (String token : flag.split("\\s*,\\s*")) {
						if (token.trim().length() <= 0)
							continue;
						String[] tokens = token.split("[\\s=]+");
						if (tokens.length == 1)
							attr.put("", tokens[0]);
						else if (tokens.length >= 2)
							attr.put(tokens[0], tokens[1]);
					}
					String value = attr.get("");
					if ("false".equals(value))
						throw new AgentException("upload feature doesn't turn on.");
					isMultiple = Boolean.parseBoolean(attr.get("multiple"));
				}

				try {
					// parameters 
					String param = "?uuid={0}&dtid={1}&sid=0&maxsize=undefined";
					param = MessageFormat.format(param, target.getUuid(), target.getDesktop().getId());
					// open connection
					String boundary = Util.generateRandomString(); // boundary for multipart
					ClientCtrl cc = (ClientCtrl) getClient();
					conn = cc.getConnection("/zkau/upload" + param, "POST");
					conn.addRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
					conn.setDoInput(true);
					conn.setDoOutput(true);
					OutputStream os = conn.getOutputStream();
					multipartStream = new MultiPartOutputStream(os, boundary);
				} catch (IOException e) {
					clean();
					throw new AgentException(e.getMessage(), e);
				}
			} else if (!isMultiple) { // check allow of multiple
				throw new AgentException("multiple upload feature doesn't turn on.");
			}

			try {
				// additional headers
				String contentDisposition = "Content-Disposition: form-data; name=\"file\"; filename=\"{0}\"";
				contentDisposition = MessageFormat.format(contentDisposition, fileName);
				String[] headers = new String[] { contentDisposition };
				// upload multipart data
				multipartStream.startPart(contentType != null ? contentType : "application/octet-stream", headers); // default content type
				int b;
				while ((b = content.read()) >= 0)
					multipartStream.write(b);
			} catch (IOException e) {
				clean();
				throw new AgentException(e.getMessage(), e);
			}
		}

		public void finish() {
			if (multipartStream == null)
				return;

			// finish upload first and get the correct key
			clean();
			int key = ((DesktopCtrl) target.getDesktop().getDelegatee()).getNextKey() - 1;
			String contentId = Strings.encode(new StringBuffer(12).append("z__ul_"), key).toString(); // copy from AuUploader
			// perform AU
			String cmd = "updateResult";
			String desktopId = target.getDesktop().getId();
			Event event = new Event(cmd, (Component) target.getDelegatee());
			Map<String, Object> data = EventDataManager.getInstance().build(event);
			data.put("wid", target.getUuid());
			data.put("contentId", contentId);
			data.put("sid", "0");
			((ClientCtrl) target.getClient()).postUpdate(desktopId, target.getUuid(), cmd, data, false);
			((ClientCtrl) target.getClient()).flush(desktopId);
		}

		private void clean() {
			// close output
			Util.close(multipartStream);
			multipartStream = null;

			// close input 
			InputStream is = null;
			try {
				String respMsg = conn.getResponseMessage();
				is = conn.getInputStream();
				String resp = IO.toString(is);
				if (logger.isLoggable(Level.FINEST)) {
					logger.finest("response message: " + respMsg);
					logger.finest("response content: " + resp);
				}
			} catch (IOException e) {
				throw new AgentException(e.getMessage(), e);
			} finally {
				Util.close(is);
				conn = null;
			}
		}
	}
}