<dependencies>

    <!-- spring boot web支持 -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- thmleaf模板依赖. -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

package com.example.controller;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;

/**
 * 文件上传的Controller
 * 
 * @author 单红宇(CSDN CATOOP)
 * @create 2017年3月11日
 */
@Controller
public class FileUploadController {

  // 访问路径为：http://ip:port/upload
  @RequestMapping(value = "/upload", method = RequestMethod.GET)
  public String upload() {
    return "/fileupload";
  }

  // 访问路径为：http://ip:port/upload/batch
  @RequestMapping(value = "/upload/batch", method = RequestMethod.GET)
  public String batchUpload() {
    return "/mutifileupload";
  }

  /**
   * 文件上传具体实现方法（单文件上传）
   *
   * @param file
   * @return
   * 
   * @author 单红宇(CSDN CATOOP)
   * @create 2017年3月11日
   */
  @RequestMapping(value = "/upload", method = RequestMethod.POST)
  @ResponseBody
  public String upload(@RequestParam("file") MultipartFile file) {
    if (!file.isEmpty()) {
      try {
        // 这里只是简单例子，文件直接输出到项目路径下。
        // 实际项目中，文件需要输出到指定位置，需要在增加代码处理。
        // 还有关于文件格式限制、文件大小限制，详见：中配置。
        BufferedOutputStream out = new BufferedOutputStream(
            new FileOutputStream(new File(file.getOriginalFilename())));
        out.write(file.getBytes());
        out.flush();
        out.close();
      } catch (FileNotFoundException e) {
        e.printStackTrace();
        return "上传失败," + e.getMessage();
      } catch (IOException e) {
        e.printStackTrace();
        return "上传失败," + e.getMessage();
      }
      return "上传成功";
    } else {
      return "上传失败，因为文件是空的.";
    }
  }

  /**
   * 多文件上传 主要是使用了MultipartHttpServletRequest和MultipartFile
   *
   * @param request
   * @return
   * 
   * @author 单红宇(CSDN CATOOP)
   * @create 2017年3月11日
   */
  @RequestMapping(value = "/upload/batch", method = RequestMethod.POST)
  public @ResponseBody String batchUpload(HttpServletRequest request) {
    List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");
    MultipartFile file = null;
    BufferedOutputStream stream = null;
    for (int i = 0; i < files.size(); ++i) {
      file = files.get(i);
      if (!file.isEmpty()) {
        try {
          byte[] bytes = file.getBytes();
          stream = new BufferedOutputStream(new FileOutputStream(new File(file.getOriginalFilename())));
          stream.write(bytes);
          stream.close();
        } catch (Exception e) {
          stream = null;
          return "You failed to upload " + i + " => " + e.getMessage();
        }
      } else {
        return "You failed to upload " + i + " because the file was empty.";
      }
    }
    return "upload successful";
  }
}

package com.example.configuration;

import javax.servlet.MultipartConfigElement;

import org.springframework.boot.web.servlet.MultipartConfigFactory;
import org.springframework.context.annotation.Bean;

/**
 * 文件上传配置
 * 
 * @author 单红宇(CSDN CATOOP)
 * @create 2017年3月11日
 */
public class FileUploadConfiguration {

  @Bean
  public MultipartConfigElement multipartConfigElement() {
    MultipartConfigFactory factory = new MultipartConfigFactory();
    // 设置文件大小限制 ,超出设置页面会抛出异常信息，
    // 这样在文件上传的地方就需要进行异常信息的处理了;
    factory.setMaxFileSize("256KB"); // KB,MB
    /// 设置总上传数据总大小
    factory.setMaxRequestSize("512KB");
    // Sets the directory location where files will be stored.
    // factory.setLocation("路径地址");
    return factory.createMultipartConfig();
  }
}

@SpringBootApplication
public class DemoUploadfileApplication {

  public static void main(String[] args) {
    SpringApplication.run(DemoUploadfileApplication.class, args);
  }
}

<!DOCTYPE html>
<html>
<head>
<title>文件上传示例</title>
</head>
<body>
  <h2>文件上传示例</h2>
  <hr/>
  <form method="POST" enctype="multipart/form-data" action="/upload">
    <p>
      文件：<input type="file" name="file" />
    </p>
    <p>
      <input type="submit" value="上传" />
    </p>
  </form>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<title>批量文件上传示例</title>
</head>
<body>
  <h2>批量文件上传示例</h2>
  <hr/>
  <form method="POST" enctype="multipart/form-data"
    action="/upload/batch">
    <p>
      文件1：<input type="file" name="file" />
    </p>
    <p>
      文件2：<input type="file" name="file" />
    </p>
    <p>
      文件3：<input type="file" name="file" />
    </p>
    <p>
      <input type="submit" value="上传" />
    </p>
  </form>
</body>
</html>