filepartsource.java

Light in the box 抓取程序。 使用HttpClient

/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/methods/multipart/FilePartSource.java,v 1.10 2004/04/18 23:51:37 jsdever Exp $
 * $Revision: 480424 $
 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 *  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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */
 
package org.apache.commons.httpclient.methods.multipart;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

/**
 * A PartSource that reads from a File.
 * 
 * @author <a href="mailto:[e-mail]">Michael Becke</a>
 * @author <a href="mailto:[e-mail]">Mark Diggory</a>
 * @author <a href="mailto:[e-mail]">Mike Bowler</a>
 *   
 * @since 2.0 
 */
public class FilePartSource implements PartSource {

    /** File part file. */
    private File file = null;

    /** File part file name. */
    private String fileName = null;
    
    /**
     * Constructor for FilePartSource.
     * 
     * @param file the FilePart source File. 
     *
     * @throws FileNotFoundException if the file does not exist or 
     * cannot be read
     */
    public FilePartSource(File file) throws FileNotFoundException {
        this.file = file;
        if (file != null) {
            if (!file.isFile()) {
                throw new FileNotFoundException("File is not a normal file.");
            }
            if (!file.canRead()) {
                throw new FileNotFoundException("File is not readable.");
            }
            this.fileName = file.getName();       
        }
    }

    /**
     * Constructor for FilePartSource.
     * 
     * @param fileName the file name of the FilePart
     * @param file the source File for the FilePart
     *
     * @throws FileNotFoundException if the file does not exist or 
     * cannot be read
     */
    public FilePartSource(String fileName, File file) 
      throws FileNotFoundException {
        this(file);
        if (fileName != null) {
            this.fileName = fileName;
        }
    }
    
    /**
     * Return the length of the file
     * @return the length of the file.
     * @see PartSource#getLength()
     */
    public long getLength() {
        if (this.file != null) {
            return this.file.length();
        } else {
            return 0;
        }
    }

    /**
     * Return the current filename
     * @return the filename.
     * @see PartSource#getFileName()
     */
    public String getFileName() {
        return (fileName == null) ? "noname" : fileName;
    }

    /**
     * Return a new {@link FileInputStream} for the current filename.
     * @return the new input stream.
     * @throws IOException If an IO problem occurs.
     * @see PartSource#createInputStream()
     */
    public InputStream createInputStream() throws IOException {
        if (this.file != null) {
            return new FileInputStream(this.file);
        } else {
            return new ByteArrayInputStream(new byte[] {});
        }
    }

}