Spring Multipart工作原理(文件上传到服务器)

Multipart工作原理


按照Multipart规定的格式将文件名和文件内容在请求中发送到服务器中

服务器从请求流中得到文件名和文件内容放入到Multipart定义的类中，
服务器处理请求中再在服务器生成相关的文件目录，并将内容保存到服务器中去



Spring applicationContext.xml配置文件：

<bean id="multipartResolver"
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver">

    <!-- one of the properties available; the maximum file size in bytes -->
    <property name="maxUploadSize" value="100000"/>
</bean>

单文件方式实现：
HTML：

<form action="http://localhost:8080/v1/TestUploadImage" method="post" id="iconForm" enctype="multipart/form-data">
    <table>
    <tr>
        <td>头像</td>
        <td><input id="iconImg" name="iconImg" type="file"/></td>
        <td><input type="submit" value="上传"/></td>
    </tr>
    </table>
</form>

JAVA：

public static String uploadFile(String uploadDir, MultipartFile file, Boolean existReplace) {
		String logString = "FileIOUtils uploadFile : ";

		String returnMsg = null;

		String fileName = file.getOriginalFilename();
		logger.info(logString + "fileName == " + fileName);

		File targetFile = new File(uploadDir, fileName);
		logger.info(logString + "targetFile == " + targetFile);

		// 文件存在
		if (!targetFile.exists()) {
			logger.info(logString + "targetFile is not exist");
			// 新建文件目录
			targetFile.mkdirs();
		} else {
			logger.info(logString + "targetFile is exist");
			if (!existReplace) {
				logger.info(logString + "existReplace is false");
				returnMsg = "exist";
				return returnMsg; // 存在不进行替换，直接返回true
			}
		}

		// 保存文件
		try {
			file.transferTo(targetFile);
		} catch (Exception e) {
			logger.error(logString + "targetFile save fail == " + e);
			returnMsg = "false";
			return returnMsg;
		}
		returnMsg = "true";
		logger.info(logString + "returnMsg ==  " + returnMsg);
		return returnMsg;
	}
}

方法1:

@RequestMapping(value = "/TestUploadImage", produces = "text/plain;charset=UTF-8")
public @ResponseBody String iconUpload(@RequestParam(value = "iconImg") MultipartFile iconImg,HttpServletRequest request,String aas ){
	MultipartHttpServletRequest multipartRequest  =  (MultipartHttpServletRequest) request;
	String fileName=multipartFile.getOriginalFilename();
	if (fileName==null){
		System.out.println("fileName==null");
	}

	if (fileName==""){
		System.out.println("fileName==''");
	}

	String tempfilename;
	if (System.getProperty("os.name").equals("Linux")) {
		tempfilename = "/opt/mcloudStat/";
	} else {
		tempfilename = "D:\\testImage";
	}

	returnMsg = FileIOUtils.uploadFile(tempfilename,multipartFile,false);
	return returnMsg;
}

方法2:

@RequestMapping(value = "/TestUploadImage", produces = "text/plain;charset=UTF-8")
public @ResponseBody String iconUpload(@RequestParam(value = "iconImg") MultipartFile iconImg,HttpServletRequest request,String aas ){
	MultipartHttpServletRequest multipartRequest  =  (MultipartHttpServletRequest) request;
	Map<String,MultipartFile> fileMap  =multipartRequest.getFileMap();

	String returnMsg = null;
	for(String key:fileMap.keySet()){
		System.out.println("key == " + key);

		if(key.equals("iconImg")){
			MultipartFile multipartFile = fileMap.get(key);

			String fileName=multipartFile.getOriginalFilename();

			if (fileName==null){
				System.out.println("fileName==null");
			}

			if (fileName==""){
				System.out.println("fileName==''");
			}

			System.out.println("fileName == " + fileName);

			String tempfilename;
			if (System.getProperty("os.name").equals("Linux")) {
				tempfilename = "/opt/mcloudStat/";
			} else {
				tempfilename = "D:\\testImage";
			}

			returnMsg = FileIOUtils.uploadFile(tempfilename,multipartFile,false);
		}
	}
	return returnMsg;
}

多文件方式实现：
HTML：

<form action="http://localhost:8080/v1/TestUploadImage" method="post" id="iconForm" enctype="multipart/form-data">
    <table>
    <tr>
        <td>头像</td>
        <td><input id="iconImg" name="iconImg" type="file"/></td>
        <td><input id="iconImg2" name="iconImg" type="file"/></td>//命字要一样，方便组成数组,会与排版顺序进行传入
        <td><input type="submit" value="上传"/></td>
    </tr>
    </table>
</form>

JAVA：
方法1:

@RequestMapping(value = "/TestUploadImage", produces = "text/plain;charset=UTF-8")
public @ResponseBody String iconUpload(@RequestParam(value = "iconImg") MultipartFile[] iconImg,HttpServletRequest request,String aas ){
	String returnMsg = null;
	int iconImgLen = iconImg.length;
	System.out.println("iconImgLen == " +iconImgLen);
	for(int i=0;i<iconImgLen;i++){
		String fileName=iconImg[i].getOriginalFilename();

		if (fileName==null){
			System.out.println("fileName==null");
		}

		if (fileName==""){
			System.out.println("fileName==''");
		}

		System.out.println("fileName == " + fileName);

		String tempfilename;
		if (System.getProperty("os.name").equals("Linux")) {
			tempfilename = "/opt/mcloudStat/";
		} else {
			tempfilename = "D:\\testImage";
		}

	        returnMsg = FileIOUtils.uploadFile(tempfilename,iconImg[i],false);
	}
	return returnMsg;
}

方法2:参考单单文方式实现方法2,不过HTML文件中的name要不一样

thumbnails可实现图片的压缩功能（PictureUtils.java）
http://blog.csdn.net/yaohucaizi/article/details/9718861