1：首先在项目的pom文件中添加两个依赖

commons-fileupload

commons-fileupload

1.3.1

net.coobird

thumbnailator

0.4.8

2：resource中添加 file-message.properties 配置文件

file-message.properties.png

配置文件内容如下

#文件压缩大小(大于4兆压缩)

message.fileSize=4194304

#图片保存路径

message.upPath=D:\\MyProjectName\\UploadData\\images

#压缩比例

message.scaleRatio=0.20f

#图片类型

message.imageType=png,jpg,jpeg

3：新建 MessageProperties 类，对应 file-message.properties 配置文件

@Component

@ConfigurationProperties(prefix="message")

@PropertySource("classpath:file-message.properties")

public class MessageProperties {

private long fileSize; //压缩大小

private double scaleRatio; //压缩比例

private String upPath; //保存路径

private String imageType; //图片类型

public long getFileSize() {

return fileSize;

}

public void setFileSize(long fileSize) {

this.fileSize = fileSize;

}

public double getScaleRatio() {

return scaleRatio;

}

public void setScaleRatio(double scaleRatio) {

this.scaleRatio = scaleRatio;

}

public String getUpPath() {

return upPath;

}

public void setUpPath(String upPath) {

this.upPath = upPath;

}

public String getImageType() {

return imageType;

}

public void setImageType(String imageType) {

this.imageType = imageType;

}

}

当然也可以不新建 file-message.properties 文件， file-message.properties 文件里的内容可以直接写在 application.properties 配置文件中，那MessageProperties 类就应该按下面这种写法：

@Component

public class MessageProperties {

@Value("${fileSize}")

private long fileSize; //压缩大小

@Value("${scaleRatio}")

private double scaleRatio; //压缩比例

@Value("${MDDIMG_LOCATION}")

private String upPath; //保存路径

@Value("${imageType}")

private String imageType; //图片类型

...

}

4：service层接口

public interface FileUpAndDownService {

Map uploadPicture(MultipartFile file) throws ServiceException;

}

5：service层接口实现

@Service

public class FileUpAndDownServiceImpl implements FileUpAndDownService {

@Autowired

private MessageProperties config; //用来获取file-message.properties配置文件中的信息

@Override

public Map uploadPicture(MultipartFile file) throws ServiceException {

try {

Map resMap = new HashMap<>();

String[] IMAGE_TYPE = config.getImageType().split(",");

String path = null;

boolean flag = false;

for (String type : IMAGE_TYPE) {

if (StringUtils.endsWithIgnoreCase(file.getOriginalFilename(), type)) {

flag = true;

break;

}

}

if (flag) {

resMap.put("result", IStatusMessage.SystemStatus.SUCCESS.getMessage());

String uuid = UUID.randomUUID().toString().replaceAll("-", "");

// 获得文件类型

String fileType = file.getContentType();

// 获得文件后缀名称

String imageName = fileType.substring(fileType.indexOf("/") + 1);

// 原名称

String oldFileName = file.getOriginalFilename();

// 新名称

String newFileName = uuid + "." + imageName;

// 年月日文件夹

SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");

String basedir = sdf.format(new Date());

// 进行压缩(大于4M)

if (file.getSize() > config.getFileSize()) {

// 重新生成

String newUUID = UUID.randomUUID().toString().replaceAll("-", "");

newFileName = newUUID + "." + imageName;

path = config.getUpPath() + "/" + basedir + "/" + newUUID + "." + imageName;

// 如果目录不存在则创建目录

File oldFile = new File(path);

if (!oldFile.exists()) {

oldFile.mkdirs();

}

file.transferTo(oldFile);

// 压缩图片

Thumbnails.of(oldFile).scale(config.getScaleRatio()).toFile(path);

// 显示路径

resMap.put("path", "/" + basedir + "/" + newUUID + "." + imageName);

} else {

path = config.getUpPath() + "/" + basedir + "/" + uuid + "." + imageName;

// 如果目录不存在则创建目录

File uploadFile = new File(path);

if (!uploadFile.exists()) {

uploadFile.mkdirs();

}

file.transferTo(uploadFile);

// 显示路径

resMap.put("path", "/" + basedir + "/" + uuid + "." + imageName);

}

resMap.put("oldFileName", oldFileName);

resMap.put("newFileName", newFileName);

resMap.put("fileSize", file.getSize());

} else {

resMap.put("result", "图片格式不正确,支持png|jpg|jpeg");

}

return resMap;

} catch (Exception e) {

e.printStackTrace();

throw new ServiceException(e.getMessage());

}

}

}

6：Controller层的实现

@Controller

@RequestMapping("/upload")

public class FileUploadController {

private static final Logger LOGGER = LoggerFactory.getLogger(FileUploadController.class);

@Autowired

private FileUpAndDownService fileUpAndDownService;

@RequestMapping(value = "/setFileUpload", method = RequestMethod.POST)

@ResponseBody

public ResponseResult setFileUpload(@RequestParam(value = "file", required = false) MultipartFile file) {

ResponseResult result = new ResponseResult();

try {

Map resultMap = upload(file);

if (!IStatusMessage.SystemStatus.SUCCESS.getMessage().equals(resultMap.get("result"))) {

result.setCode(IStatusMessage.SystemStatus.PARAM_ERROR.getCode());

result.setMessage((String) resultMap.get("msg"));

return result;

}

result.setData(resultMap);

} catch (ServiceException e) {

e.printStackTrace();

LOGGER.error(">>>>>>图片上传异常，e={}", e.getMessage());

result.setCode(IStatusMessage.SystemStatus.ERROR.getCode());

result.setMessage(IStatusMessage.FILE_UPLOAD_ERROR);

}

return result;

}

private Map upload(MultipartFile file) throws ServiceException {

Map returnMap = new HashMap<>();

try {

if (!file.isEmpty()) {

Map picMap = fileUpAndDownService.uploadPicture(file);

if (IStatusMessage.SystemStatus.SUCCESS.getMessage().equals(picMap.get("result"))) {

return picMap;

} else {

returnMap.put("result", IStatusMessage.SystemStatus.ERROR.getMessage());

returnMap.put("msg", picMap.get("result"));

}

} else {

LOGGER.info(">>>>>>上传图片为空文件");

returnMap.put("result", IStatusMessage.SystemStatus.ERROR.getMessage());

returnMap.put("msg", IStatusMessage.FILE_UPLOAD_NULL);

}

} catch (Exception e) {

e.printStackTrace();

throw new ServiceException(IStatusMessage.FILE_UPLOAD_ERROR);

}

return returnMap;

}

}

7：springboot项目中还需要添加下面一段代码到Application启动类中

@SpringBootApplication

//exclude表示自动配置时不包括Multipart配置

@EnableAutoConfiguration(exclude = {MultipartAutoConfiguration.class})

public class StartApplication {

public static void main(String[] args) {

...

}

/**

* 显示声明CommonsMultipartResolver为mutipartResolver

*/

@Bean(name = "multipartResolver")

public MultipartResolver multipartResolver() {

CommonsMultipartResolver resolver = new CommonsMultipartResolver();

//resolver.setDefaultEncoding("UTF-8");

//resolveLazily属性启用是为了推迟文件解析，以在在UploadAction中捕获文件大小异常

resolver.setResolveLazily(true);

resolver.setMaxInMemorySize(40960);

resolver.setMaxUploadSize(3 * 1024 * 1024);//上传文件大小 3M 3*1024*1024

return resolver;

}

}

顶部 @EnableAutoConfiguration(exclude = {MultipartAutoConfiguration.class}) 注解不要忘了

这两段代码不加的话，可能会造成图片上传成文件夹形式，上传失败！

8：前端HTML界面，直接使用layui

HTML：

上传

JS：

layui.use('upload', function () {

var upload = layui.upload;

//执行实例

var uploadInst = upload.render({

elem: '#uploadBtn' //绑定元素

, url: '/upload/setFileUpload' //上传接口

, multiple: true

, before: function (obj) {

//可设置回显

console.log(obj)

}

, done: function (res) {

console.log(res);

//上传完毕回调

if (res.code != 1000) {

return layer.msg('上传失败');

} else {

return layer.msg('上传成功');

}

}

, error: function () {

//请求异常回调

}

});

});

上传成功后会返回如下信息：

上传成功.png

上传失败：

上传失败.png

ServiceException为自定义接口异常处理：

public class ServiceException extends Exception {

public ServiceException() {

super();

}

public ServiceException(String message){

super(message);

}

public ServiceException(Throwable throwable){

super(throwable);

}

public ServiceException(String message ,Throwable throwable){

super(message, throwable);

}

}

IStatusMessage为自定义响应状态信息枚举类：

public interface IStatusMessage {

String getCode();

String getMessage();

enum SystemStatus implements IStatusMessage {

SUCCESS("1000", "操作成功"), //请求成功

ERROR("1001", "网络异常，请稍后重试~"),

FILE_UPLOAD_NULL("1002","上传图片为空文件"), ; //请求失败

private String code;

private String message;

SystemStatus(String code, String message) {

this.code = code;

this.message = message;

}

public String getCode() {

return this.code;

}

public String getMessage() {

return this.message;

}

}

}

ResponseResult前端响应结果类：

import java.io.Serializable;

import java.util.HashMap;

import java.util.Map;

public class ResponseResult implements Serializable {

private static final long serialVersionUID = -148117940294941578L;

private String code;

private String message;

private Object obj;

private Map data; //默认为hashMap,也可为对象

public String getCode() {

return code;

}

public ResponseResult() {

this.code = IStatusMessage.SystemStatus.SUCCESS.getCode();

this.message = IStatusMessage.SystemStatus.SUCCESS.getMessage();

}

public ResponseResult(IStatusMessage statusMessage){

this.code = statusMessage.getCode();

this.message = statusMessage.getMessage();

}

public void setCode(String code) {

this.code = code;

}

public String getMessage() {

return message;

}

public void setMessage(String message) {

this.message = message;

}

public Object getObj() {

return obj;

}

public void setObj(Object obj) {

this.obj = obj;

}

public Map getData() {

return data;

}

public void setData(Map data) {

this.data = data;

}

public void putData(String key,Object value){

if( this. data == null ){

this.data = new HashMap();

}

this.data.put(key, value);

}

}