DownloadWriter.java

/*
 * Created on 23.8.2004
 * 
 * Copyright (C) 2004 Idega hf. All Rights Reserved.
 * 
 * This software is the proprietary information of Idega hf. Use is subject to
 * license terms.
 */
package com.idega.io;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import javax.servlet.http.HttpServletRequest;
import com.idega.core.file.business.ICFileSystem;
import com.idega.core.file.business.ICFileSystemFactory;
import com.idega.core.file.data.ICFile;
import com.idega.core.file.data.ICFileHome;
import com.idega.data.IDOLookup;
import com.idega.presentation.IWContext;

/**
 * @author aron
 * 
 * DownloadWriter To be used when files are downloaded to the user. The response
 * is set so that the client browser opens a save dialog. Handles both files
 * from database and absolute paths from filesystem if read permission is active
 */
public class DownloadWriter implements MediaWritable {

	public final static String PRM_ABSOLUTE_FILE_PATH = "abs_fpath";

	public final static String PRM_RELATIVE_FILE_PATH = "rel_fpath";

	public final static String PRM_FILE_NAME = "alt_f_name";

	public final static String PRM_FILE_ID = "fileId";

	private File file = null;

	private ICFile icFile = null;

	private URL url = null;

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.idega.io.MediaWritable#getMimeType()
	 */
	public String getMimeType() {
		return "application/octet-stream";
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.idega.io.MediaWritable#init(javax.servlet.http.HttpServletRequest,
	 *      com.idega.presentation.IWContext)
	 */
	public void init(HttpServletRequest req, IWContext iwc) {
		String fileId = iwc.getParameter(PRM_FILE_ID);
		String absPath = iwc.getParameter(PRM_ABSOLUTE_FILE_PATH);
		String relPath = iwc.getParameter(PRM_RELATIVE_FILE_PATH);
		String altFileName = iwc.getParameter(PRM_FILE_NAME);
		if (fileId != null) {
			try {
				ICFileSystem fsystem = ICFileSystemFactory.getFileSystem(iwc);
				String fileURL = fsystem.getFileURI(Integer.valueOf(fileId).intValue());
				this.file = new File(iwc.getIWMainApplication().getRealPath(fileURL));
				this.icFile = ((ICFileHome) IDOLookup.getHome(ICFile.class)).findByPrimaryKey(Integer.valueOf(fileId));
				//setAsDownload(iwc,icFile.getName(),icFile.getFileSize().intValue());
				if (altFileName != null) {
					setAsDownload(iwc, altFileName, (int) this.file.length());
				}
				else {
					setAsDownload(iwc, this.file.getName(), (int) this.file.length());					
				}
			}
			catch (Exception e) {
				this.icFile = null;
			}
		}
		else if (absPath != null) {
			this.file = new File(absPath);
			if (this.file != null && this.file.exists() && this.file.canRead()) {
				setAsDownload(iwc, this.file.getName(), (int) this.file.length());
			}
		}
		else if (relPath != null && altFileName == null) {
			this.file = new File(iwc.getIWMainApplication().getRealPath(relPath));
			if (this.file != null && this.file.exists() && this.file.canRead()) {
				setAsDownload(iwc, this.file.getName(), (int) this.file.length());
			}
		}
		else if (relPath != null && altFileName != null) {
			try {
				if(relPath.startsWith("/")){
					relPath = relPath.substring(1);
				}
				this.url = new URL(iwc.getServerURL()+relPath);
				setAsDownload(iwc, altFileName, -1);
			}
			catch (MalformedURLException e) {
				e.printStackTrace();
			}
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.idega.io.MediaWritable#writeTo(java.io.OutputStream)
	 */
	public void writeTo(OutputStream out) throws IOException {
		if (this.file != null && this.file.exists() && this.file.canRead() && this.file.length() > 0) {
			BufferedInputStream fis = new BufferedInputStream(new FileInputStream(this.file));
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			while (fis.available() > 0) {
				baos.write(fis.read());
			}
			baos.writeTo(out);
			baos.flush();
			baos.close();
			fis.close();
		}
		else if (this.icFile != null) {
			BufferedInputStream fis = new BufferedInputStream(this.icFile.getFileValue());
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			while (fis.available() > 0) {
				baos.write(fis.read());
			}
			baos.writeTo(out);
			baos.flush();
			baos.close();
			fis.close();
		}
		else if (this.url != null) {
			//added for real relative path streaming
			BufferedInputStream input = new BufferedInputStream(this.url.openStream());
			byte buffer[] = new byte[1024];
			int noRead = 0;
			noRead = input.read(buffer, 0, 1024);
			//Write out the stream to the file
			while (noRead != -1) {
				out.write(buffer, 0, noRead);
				noRead = input.read(buffer, 0, 1024);
			}
		}
		else {
			throw new IOException("No file value");
		}
	}

	public void setAsDownload(IWContext iwc, String filename, int fileLength) {
		iwc.getResponse().setHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");
		if (fileLength > 0) {
			iwc.getResponse().setContentLength(fileLength);
		}
	}
}