java 模拟ajax上传图片

1、maven 引入依赖

　　

	<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
    <version>4.5.2</version>
</dependency>
	<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpcore -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpcore</artifactId>
    <version>4.4.9</version>
</dependency>

　　

　2、

@RequestMapping("upload")
	public ResultMessage upload(HttpServletRequest request,HttpServletResponse response,
			@RequestParam(name="userid",required=false)String userid,
			@RequestParam(name="bid",required=false)String bid,
			@RequestParam(name="pid",required=false)String pid,
			@RequestParam(name="reportNumber",required=false)String reportNumber,
			@RequestParam(name="plateNumber",required=false)String plateNumber,
			@RequestParam("file") MultipartFile file) throws IllegalStateException, IOException{
		String filename=file.getOriginalFilename();
    	String extensionName = filename.substring(filename.lastIndexOf(".") + 1);
    	String imgPath = System.currentTimeMillis() + "." +extensionName;
        String filePath = request.getSession().getServletContext().getRealPath("/")+"uploadimages\\";
        File newfile =  new File(filePath);
        if(!newfile.exists()){
        	newfile.mkdirs();
        }
        file.transferTo(new File(filePath+imgPath));
		HttpClient client = new DefaultHttpClient();
		HttpPost post= new HttpPost("");
		MultipartEntity muti = new MultipartEntity();
		File newfile1 = new File(filePath+imgPath);
		FileBody body = new FileBody(newfile1);
		muti.addPart("file",body);
		muti.addPart("userid", new StringBody(userid));
		muti.addPart("pid", new StringBody(pid));
		muti.addPart("bid", new StringBody(bid));
		muti.addPart("reportNumber", new StringBody(reportNumber));
		muti.addPart("plateNumber", new StringBody(plateNumber));
		post.setEntity(muti);
		try {
			HttpResponse resp = client.execute(post);
			if(resp.getStatusLine().getStatusCode()==HttpStatus.SC_OK){
				return ResultMessage.getSuccess().setData(EntityUtils.toString(resp.getEntity()));
			}
		}catch (IOException e) {
			logger.info(e.getMessage(),e);
		}
		return ResultMessage.getFail();
		
	}

<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime --><dependency>    <groupId>org.apache.httpcomponents</groupId>    <artifactId>httpmime</artifactId>    <version>4.5.2</version></dependency>