fileuploadbase.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.util.upload;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * <p>
 * High level API for processing file uploads.
 * </p>
 *
 * <p>
 * This class handles multiple files per single HTML widget, sent using <code>multipart/mixed</code>
 * encoding type, as specified by <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC 1867</a>.
 *
 * <p>
 * How the data for individual parts is stored is determined by the factory used to create them; a
 * given part may be in memory, on disk, or somewhere else.
 * </p>
 *
 * @author <a href="mailto:[e-mail]">Rafal Krzewski</a>
 * @author <a href="mailto:[e-mail]">Daniel Rall</a>
 * @author <a href="mailto:[e-mail]">Jason van Zyl</a>
 * @author <a href="mailto:[e-mail]">John McNally</a>
 * @author <a href="mailto:[e-mail]">Martin Cooper</a>
 * @author Sean C. Sullivan
 */
public abstract class FileUploadBase
{

	// ---------------------------------------------------------- Class methods


	/**
	 * <p>
	 * Utility method that determines whether the request contains multipart content.
	 * </p>
	 *
	 * <p>
	 * <strong>NOTE:</strong>This method will be moved to the <code>ServletFileUpload</code>
	 * class after the FileUpload 1.1 release. Unfortunately, since this method is static, it is not
	 * possible to provide its replacement until this method is removed.
	 * </p>
	 *
	 * @param ctx
	 *            The request context to be evaluated. Must be non-null.
	 *
	 * @return <code>true</code> if the request is multipart; <code>false</code> otherwise.
	 */
	public static final boolean isMultipartContent(RequestContext ctx)
	{
		String contentType = ctx.getContentType();
		if (contentType == null)
		{
			return false;
		}
		if (contentType.toLowerCase().startsWith(MULTIPART))
		{
			return true;
		}
		return false;
	}

	// ----------------------------------------------------- Manifest constants


	/**
	 * HTTP content type header name.
	 */
	public static final String CONTENT_TYPE = "Content-type";


	/**
	 * HTTP content disposition header name.
	 */
	public static final String CONTENT_DISPOSITION = "Content-disposition";


	/**
	 * Content-disposition value for form data.
	 */
	public static final String FORM_DATA = "form-data";


	/**
	 * Content-disposition value for file attachment.
	 */
	public static final String ATTACHMENT = "attachment";


	/**
	 * Part of HTTP content type header.
	 */
	public static final String MULTIPART = "multipart/";


	/**
	 * HTTP content type header for multipart forms.
	 */
	public static final String MULTIPART_FORM_DATA = "multipart/form-data";


	/**
	 * HTTP content type header for multiple uploads.
	 */
	public static final String MULTIPART_MIXED = "multipart/mixed";


	/**
	 * The maximum length of a single header line that will be parsed (1024 bytes).
	 */
	public static final int MAX_HEADER_SIZE = 1024;


	// ----------------------------------------------------------- Data members


	/**
	 * The maximum size permitted for an uploaded file. A value of -1 indicates no maximum.
	 */
	private long sizeMax = -1;


	/**
	 * The content encoding to use when reading part headers.
	 */
	private String headerEncoding;


	// ----------------------------------------------------- Property accessors


	/**
	 * Returns the factory class used when creating file items.
	 *
	 * @return The factory class for new file items.
	 */
	public abstract FileItemFactory getFileItemFactory();


	/**
	 * Sets the factory class to use when creating file items.
	 *
	 * @param factory
	 *            The factory class for new file items.
	 */
	public abstract void setFileItemFactory(FileItemFactory factory);


	/**
	 * Returns the maximum allowed upload size.
	 *
	 * @return The maximum allowed size, in bytes.
	 *
	 * @see #setSizeMax(long)
	 *
	 */
	public long getSizeMax()
	{
		return sizeMax;
	}


	/**
	 * Sets the maximum allowed upload size. If negative, there is no maximum.
	 *
	 * @param sizeMax
	 *            The maximum allowed size, in bytes, or -1 for no maximum.
	 *
	 * @see #getSizeMax()
	 *
	 */
	public void setSizeMax(long sizeMax)
	{
		this.sizeMax = sizeMax;
	}


	/**
	 * Retrieves the character encoding used when reading the headers of an individual part. When
	 * not specified, or <code>null</code>, the platform default encoding is used.
	 *
	 * @return The encoding used to read part headers.
	 */
	public String getHeaderEncoding()
	{
		return headerEncoding;
	}


	/**
	 * Specifies the character encoding to be used when reading the headers of individual parts.
	 * When not specified, or <code>null</code>, the platform default encoding is used.
	 *
	 * @param encoding
	 *            The encoding used to read part headers.
	 */
	public void setHeaderEncoding(String encoding)
	{
		headerEncoding = encoding;
	}


	// --------------------------------------------------------- Public methods

	/**
	 * Processes an <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC 1867</a> compliant
	 * <code>multipart/form-data</code> stream.
	 *
	 * @param ctx
	 *            The context for the request to be parsed.
	 *
	 * @return A list of <code>FileItem</code> instances parsed from the request, in the order
	 *         that they were transmitted.
	 *
	 * @exception FileUploadException
	 *                if there are problems reading/parsing the request or storing files.
	 */
	public List /* FileItem */parseRequest(RequestContext ctx) throws FileUploadException
	{
		if (ctx == null)
		{
			throw new IllegalArgumentException("ctx parameter cannot be null");
		}

		ArrayList items = new ArrayList();
		String contentType = ctx.getContentType();

		if ((null == contentType) || (!contentType.toLowerCase().startsWith(MULTIPART)))
		{
			throw new InvalidContentTypeException("the request doesn't contain a " +
					MULTIPART_FORM_DATA + " or " + MULTIPART_MIXED +
					" stream, content type header is " + contentType);
		}
		int requestSize = ctx.getContentLength();

		if (requestSize == -1)
		{
			throw new UnknownSizeException("the request was rejected because its size is unknown");
		}

		if (sizeMax >= 0 && requestSize > sizeMax)
		{
			throw new SizeLimitExceededException("the request was rejected because "
					+ "its size exceeds allowed range");
		}

		try
		{
			byte[] boundary = getBoundary(contentType);
			if (boundary == null)
			{
				throw new FileUploadException("the request was rejected because "
						+ "no multipart boundary was found");
			}

			InputStream input = ctx.getInputStream();

			MultipartFormInputStream multi = new MultipartFormInputStream(input, boundary);
			multi.setHeaderEncoding(headerEncoding);

			boolean nextPart = multi.skipPreamble();

			// Don't allow a header larger than this size (to prevent DOS
			// attacks)
			final int maxHeaderBytes = 65536;
			while (nextPart)
			{
				Map headers = parseHeaders(multi.readHeaders(maxHeaderBytes));
				String fieldName = getFieldName(headers);
				if (fieldName != null)
				{
					String subContentType = getHeader(headers, CONTENT_TYPE);
					if (subContentType != null &&
							subContentType.toLowerCase().startsWith(MULTIPART_MIXED))
					{
						// Multiple files.
						byte[] subBoundary = getBoundary(subContentType);
						multi.setBoundary(subBoundary);
						boolean nextSubPart = multi.skipPreamble();
						while (nextSubPart)
						{
							headers = parseHeaders(multi.readHeaders(maxHeaderBytes));
							if (getFileName(headers) != null)
							{
								FileItem item = createItem(headers, false);
                                items.add(item);
								OutputStream os = item.getOutputStream();
								try
								{
									multi.readBodyData(os);
								}
								finally
								{
									os.close();
								}
							}
							else
							{
								// Ignore anything but files inside
								// multipart/mixed.
								multi.discardBodyData();
							}
							nextSubPart = multi.readBoundary();
						}
						multi.setBoundary(boundary);
					}
					else
					{
						FileItem item = createItem(headers, getFileName(headers) == null);
                        items.add(item);
						OutputStream os = item.getOutputStream();
						try