diskfile.java

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package jaction.upload;

import java.io.File;
import java.io.InputStream;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.Serializable;

/**
 * 磁盘文件包装类
 * @author 
 * @version 1.4 $Revision: 1.0 $ 
 */
public class DiskFile implements FormFile,Serializable {
    
    /**
     * The filepath to the temporary file
     */
    protected String filePath;
    
    /**
     * The content type of the file
     */
    protected String contentType;
    
    /**
     * The size in bytes of the file
     */
    protected int fileSize;
    
    /**
     * The name of the file
     */
    protected String fileName;   
    
    public DiskFile(String filePath) {
        this.filePath = filePath;
    }
    
    /**
     * Attempt to read the temporary file and get it's data in byte
     * array form.  Tries to read the entire file (using a byte array
     * the size of getFileSize()) at once, in one call to FileInputStream.read(byte[]).
     * For buffered reading, see {@link #getFileData(int) getFileData(int)}.
     * Note that this method can be dangerous, and that the size of a file
     * can cause an OutOfMemoryError quite easily.  You should use 
     * {@link #getInputStream() getInputStream} and do your own thing.
     *
     * @exception ServletException If the temp file no longer exists, or if there is
     *                    some sort of IOException
     * @see #getFileData(int)
     */    
    public byte[] getFileData() throws FileNotFoundException, IOException {
        
        byte[] bytes = new byte[getFileSize()];
        
        FileInputStream fis = new FileInputStream(filePath);
        fis.read(bytes);
        fis.close();
        return bytes;
    }
    
    /**
     * Attempts to read a file n bytes at a time, n being equal to "bufferSize".
     * Note that this method can be dangerous, and that the size of a file
     * can cause an OutOfMemoryError quite easily.  You should use 
     * {@link #getInputStream() getInputStream} and do your own thing.
     *
     * @param bufferSize The size in bytes that are read from the file at a time
     * @exception FileNotFoundException If the temp file no longer exists
     */    
    public byte[] getFileData(int bufferSize) throws FileNotFoundException, IOException {
        
        ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
        FileInputStream fis = new FileInputStream(filePath);
        
        int readLength  = 0;
        int totalLength = 0;
        int offset      = 0;
        
        byte[] bytes = new byte[bufferSize];
        
        while ((readLength = fis.read(bytes, offset, bufferSize)) != -1) {
            
            byteStream.write(bytes, offset, bufferSize);            
            totalLength += readLength;
            offset += readLength;
        }
        
        bytes = byteStream.toByteArray();
        
        fis.close();
        byteStream.close();
        
        return bytes;      
    }
    
    
    /**
     * Delete the temporary file.
     */
    public void destroy() {
        
        File tempFile = new File(filePath);
        
        if (tempFile.exists()) {
            tempFile.delete();
        }    
    }
    
    /**
     * Get the temporary file path for this form file
     * @return A filepath to the temporary file
     */
    public String getFilePath() {
        return filePath;
    }
    
    /**
     * Set the file name
     */
    public void setFileName(String filename) {
        this.fileName = filename;
    }
    
    /**
     * Set the content type
     */
    public void setContentType(String contentType) {
        this.contentType = contentType;
    }
    
    /**
     * Set the file size
     * @param fileSize The size of the file in bytes
     */
    public void setFileSize(int fileSize) {
        this.fileSize = fileSize;
    }
    
    /**
     * Get the file name
     */
    public String getFileName() {
        return fileName;
    }
    
    /**
     * Get the content type
     */
    public String getContentType() {
        return contentType;
    }
    
    /**
     * Get the file size
     * @return The size of this file in bytes
     */
    public int getFileSize() {
        return fileSize;
    }
    
    /**
     * Returns a FileInputStream to the file
     */
    public InputStream getInputStream() throws FileNotFoundException, IOException {
        return new FileInputStream(filePath);
    }
}