Spring之MultipartFile传送文件示例分享

Spring简介:

     Spring框架是一个开放源代码的J2EE应用程序框架，由Rod Johnson发起，是针对bean的生命周期进行管理的轻量级容器（lightweight container）。 Spring解决了开发者在J2EE开发中遇到的许多常见的问题，提供了功能强大IOC、AOP及Web MVC等功能。Spring可以单独应用于构筑应用程序，也可以和Struts、Webwork、Tapestry等众多Web框架组合使用，并且可以与 Swing等桌面应用程序AP组合。因此， Spring不仅仅能应用于J2EE应用程序之中，也可以应用于桌面应用程序以及小应用程序之中。Spring框架主要由七部分组成，分别是 Spring Core、 Spring AOP、 Spring ORM、 Spring DAO、Spring Context、 Spring Web和 Spring Web MVC。

 MultipartFile是springframe封装好的一个专门用于文件上传的接口

    MultipartFile是一个接口，如下所示:

public interface MultipartFile {
 
    /**
     * Return the name of the parameter in the multipart form.
     * @return the name of the parameter (never {@code null} or empty)
     */
    String getName();
 
    /**
     * Return the original filename in the client"s filesystem.
     * <p>This may contain path information depending on the browser used,
     * but it typically will not with any other than Opera.
     * @return the original filename, or the empty String if no file
     * has been chosen in the multipart form, or {@code null}
     * if not defined or not available
     */
    String getOriginalFilename();
 
    /**
     * Return the content type of the file.
     * @return the content type, or {@code null} if not defined
     * (or no file has been chosen in the multipart form)
     */
    String getContentType();
 
    /**
     * Return whether the uploaded file is empty, that is, either no file has
     * been chosen in the multipart form or the chosen file has no content.
     */
    boolean isEmpty();
 
    /**
     * Return the size of the file in bytes.
     * @return the size of the file, or 0 if empty
     */
    long getSize();
 
    /**
     * Return the contents of the file as an array of bytes.
     * @return the contents of the file as bytes, or an empty byte array if empty
     * @throws IOException in case of access errors (if the temporary store fails)
     */
    byte[] getBytes() throws IOException;
 
    /**
     * Return an InputStream to read the contents of the file from.
     * The user is responsible for closing the stream.
     * @return the contents of the file as stream, or an empty stream if empty
     * @throws IOException in case of access errors (if the temporary store fails)
     */
    InputStream getInputStream() throws IOException;
 
    /**
     * Transfer the received file to the given destination file.
     * <p>This may either move the file in the filesystem, copy the file in the
     * filesystem, or save memory-held contents to the destination file.
     * If the destination file already exists, it will be deleted first.
     * <p>If the file has been moved in the filesystem, this operation cannot
     * be invoked again. Therefore, call this method just once to be able to
     * work with any storage mechanism.
     * @param dest the destination file
     * @throws IOException in case of reading or writing errors
     * @throws IllegalStateException if the file has already been moved
     * in the filesystem and is not available anymore for another transfer
     */
    void transferTo(File dest) throws IOException, IllegalStateException;
 
}