Spring Framework example source code file (CommonsMultipartFile.java)

This example Spring Framework source code file (CommonsMultipartFile.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

commonsmultipartfile, could, diskfileitem, diskfileitem, file, fileitem, fileuploadexception, illegalstateexception, illegalstateexception, inputstream, io, ioexception, ioexception, string, string

The Spring Framework CommonsMultipartFile.java source code

/*
 * Copyright 2002-2006 the original author or authors.
 *
 * Licensed 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.springframework.web.multipart.commons;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.Serializable;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItem;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.web.multipart.MultipartFile;

/**
 * MultipartFile implementation for Jakarta Commons FileUpload.
 *
 * <p>NOTE: As of Spring 2.0, this class requires Commons FileUpload 1.1
 * or higher. The implementation does not use any deprecated FileUpload 1.0 API
 * anymore, to be compatible with future Commons FileUpload releases.
 *
 * @author Trevor D. Cook
 * @author Juergen Hoeller
 * @since 29.09.2003
 * @see CommonsMultipartResolver
 */
public class CommonsMultipartFile implements MultipartFile, Serializable {

	protected static final Log logger = LogFactory.getLog(CommonsMultipartFile.class);

	private final FileItem fileItem;

	private final long size;


	/**
	 * Create an instance wrapping the given FileItem.
	 * @param fileItem the FileItem to wrap
	 */
	public CommonsMultipartFile(FileItem fileItem) {
		this.fileItem = fileItem;
		this.size = this.fileItem.getSize();
	}

	/**
	 * Return the underlying <code>org.apache.commons.fileupload.FileItem
	 * instance. There is hardly any need to access this.
	 */
	public final FileItem getFileItem() {
		return this.fileItem;
	}


	public String getName() {
		return this.fileItem.getFieldName();
	}

	public String getOriginalFilename() {
		String filename = this.fileItem.getName();
		if (filename == null) {
			// Should never happen.
			return "";
		}
		// check for Unix-style path
		int pos = filename.lastIndexOf("/");
		if (pos == -1) {
			// check for Windows-style path
			pos = filename.lastIndexOf("\\");
		}
		if (pos != -1)  {
			// any sort of path separator found
			return filename.substring(pos + 1);
		}
		else {
			// plain name
			return filename;
		}
	}

	public String getContentType() {
		return this.fileItem.getContentType();
	}

	public boolean isEmpty() {
		return (this.size == 0);
	}

	public long getSize() {
		return this.size;
	}

	public byte[] getBytes() {
		if (!isAvailable()) {
			throw new IllegalStateException("File has been moved - cannot be read again");
		}
		byte[] bytes = this.fileItem.get();
		return (bytes != null ? bytes : new byte[0]);
	}

	public InputStream getInputStream() throws IOException {
		if (!isAvailable()) {
			throw new IllegalStateException("File has been moved - cannot be read again");
		}
		InputStream inputStream = this.fileItem.getInputStream();
		return (inputStream != null ? inputStream : new ByteArrayInputStream(new byte[0]));
	}

	public void transferTo(File dest) throws IOException, IllegalStateException {
		if (!isAvailable()) {
			throw new IllegalStateException("File has already been moved - cannot be transferred again");
		}

		if (dest.exists() && !dest.delete()) {
			throw new IOException(
					"Destination file [" + dest.getAbsolutePath() + "] already exists and could not be deleted");
		}

		try {
			this.fileItem.write(dest);
			if (logger.isDebugEnabled()) {
				String action = "transferred";
				if (!this.fileItem.isInMemory()) {
					action = isAvailable() ? "copied" : "moved";
				}
				logger.debug("Multipart file '" + getName() + "' with original filename [" +
						getOriginalFilename() + "], stored " + getStorageDescription() + ": " +
						action + " to [" + dest.getAbsolutePath() + "]");
			}
		}
		catch (FileUploadException ex) {
			throw new IllegalStateException(ex.getMessage());
		}
		catch (IOException ex) {
			throw ex;
		}
		catch (Exception ex) {
			logger.error("Could not transfer to file", ex);
			throw new IOException("Could not transfer to file: " + ex.getMessage());
		}
	}

	/**
	 * Determine whether the multipart content is still available.
	 * If a temporary file has been moved, the content is no longer available.
	 */
	protected boolean isAvailable() {
		// If in memory, it's available.
		if (this.fileItem.isInMemory()) {
			return true;
		}
		// Check actual existence of temporary file.
		if (this.fileItem instanceof DiskFileItem) {
			return ((DiskFileItem) this.fileItem).getStoreLocation().exists();
		}
		// Check whether current file size is different than original one.
		return (this.fileItem.getSize() == this.size);
	}

	/**
	 * Return a description for the storage location of the multipart content.
	 * Tries to be as specific as possible: mentions the file location in case
	 * of a temporary file.
	 */
	public String getStorageDescription() {
		if (this.fileItem.isInMemory()) {
			return "in memory";
		}
		else if (this.fileItem instanceof DiskFileItem) {
			return "at [" + ((DiskFileItem) this.fileItem).getStoreLocation().getAbsolutePath() + "]";
		}
		else {
			return "on disk";
		}
	}

}