Image upload return value analysis
{
"error":0
"url":图片的保存路径
"width":图片的宽度
"height":图片的高度
}
error: Indicates the error message 0 Upload successful!! 1. Upload failed.
URL address: virtual path address of the picture (distinguish from the real disk address)
width/height: required attribute as picture/width and height.
Commodity echo VO package
structure
@Data
@Accessors(chain = true)
@NoArgsConstructor
@AllArgsConstructor
public class ImageVO {
private Integer error;
private String url;
private Integer width;
private Integer height;
// {"error":0,"url":"图片的保存路径","width":图片的宽度,"height":图片的高度}
public static ImageVO fail(){
return new ImageVO(1,null,null,null);
}
public static ImageVO success(String url,Integer width,Integer height){
return new ImageVO(1,null,null,null);
}
}
给客户端发送的信息
annotation
@Data
@Accessors(chain = true)
@NoArgsConstructor
@AllArgsConstructor
- Data-is Lombok's annotations to implement get/set methods and tostring methods
- Accessors(chain = true)-is the method name optimization of the current class
- NoArgsConstructor-No-argument construction
- AllArgsConstructor-parameterized construction
Package status and information
private Integer error;
private String url;
private Integer width;
private Integer height;
Package status code, address, height and width
Return method
public static ImageVO fail(){
return new ImageVO(1,null,null,null);
}
错误的返回值
public static ImageVO success(String url,Integer width,Integer height){
return new ImageVO(1,null,null,null);
}
正确的返回值
controller layer
@RestController
@CrossOrigin("http://localhost:8081")
@RequestMapping("/")
public class imageController {
@Autowired
private ImageService imageService;
@PostMapping("upload")
public ImageVO uploadFile(MultipartFile uploadFile){
return imageService.upload(uploadFile);
}
}
MultipartFile-The method is to upload files exclusively, and the files sent on the page are accepted in this way
Edit the properties configuration file
image.localDirPath=E:/Tmooc_image
image.urlPath=localhost:8080
- 1-The address where the picture is saved
- 2-Know the domain name from the link shown in the picture
service business layer
structure
@Service
@PropertySource(value = "classpath:/properties/image.properties",encoding = "UTF-8")
public class FileServiceImpl implements FileService{
@Value("${image.localDirPath}")
private String localDirPath; // = "E:/Tmooc_image";
@Value("${image.urlPath}")
private String urlPath; // = "localhost:8080";
@Override
public ImageVO upload(MultipartFile uploadFile){
//1.校验文件类型 abc.jpg
String fileName = uploadFile.getOriginalFilename().toLowerCase();
//1.1 利用正则表达式校验是否满足图片格式要求
if(!fileName.matches("^.+\\.(jpg|png|gif)$")){
return ImageVO.fail();
}
//2.校验是否为图片对象
try {
BufferedImage bufferedImage = ImageIO.read(uploadFile.getInputStream());
int width = bufferedImage.getWidth();
int height = bufferedImage.getHeight();
if(width==0 || height==0){
return ImageVO.fail();
}
//3.实现分目录存储
//3.1 动态生成hashcode编码 之后2位一隔 生成多级目录.目录层级太深 笛卡尔积较大 遍历不便
//3.2 可以动态以当前的时间为存储的目录结构 yyyy/MM/dd
String dateDirPath =
new SimpleDateFormat("/yyyy/MM/dd/").format(new Date());
//文件存储的目录 E:/Tmooc_image/2021/01/26/
String fileDirPath = localDirPath + dateDirPath;
File fileDir = new File(fileDirPath);
if(!fileDir.exists()){
//判断文件目录是否存在
fileDir.mkdirs(); //创建目录
}
//4.利用UUID动态生图片名称 uuid.jpg
String uuid =
UUID. randomUUID().toString().replace("-", "");
//abc.jpg
String fileType = fileName.substring(fileName.lastIndexOf("."));
String newFileName = uuid + fileType;
//5.实现文件上传
File realFile = new File(fileDirPath + newFileName);
uploadFile.transferTo(realFile);
//6.编辑图片的虚拟路径
//6.1磁盘地址: E:\JT_IMAGE\2021\01\26\1b0e435933ac42cabec53b20ffbcfe90.png
//6.2虚拟地址 http://image.jt.com\2021\01\26\1b0e435933ac42cabec53b20ffbcfe90.png
String url = urlPath + dateDirPath + newFileName;
return ImageVO.success(url,width,height);
} catch (IOException e) {
e.printStackTrace();
return ImageVO.fail();
}
}
Our file upload is only realized after the business has passed various tests
- 1-The suffix of the picture is verified whether the file upload is a picture type? jpg|png|gif...
- 2-To prevent malicious program Trojan horse.exe.jpg
- 3-In order to ensure the retrieval speed, the pictures need to be stored in directories.
- 4-How to prevent duplicate file names???
1-Verify that the file upload is of image type
//1.校验文件类型 abc.jpg
String fileName = uploadFile.getOriginalFilename().toLowerCase();
//1.1 利用正则表达式校验是否满足图片格式要求
if(!fileName.matches("^.+\\.(jpg|png|gif)$")){
return ImageVO.fail();
}
uploadFile-get the picture
getOriginalFilename() – Get the name of the uploaded image
toLowerCase()-Change the name of the picture to lowercase
图片的后缀不许跟我们设定的一摸一样
2-Check whether it is a picture object
BufferedImage bufferedImage = ImageIO.read(uploadFile.getInputStream());
int width = bufferedImage.getWidth();
int height = bufferedImage.getHeight();
if(width==0 || height==0){
return ImageVO.fail();
}
ImageIO-is java's own tool class io stream method to get pictures
read —— is the way to get the image path in the image ImageIO
uploadFile.getInputStream()-dynamically get the picture sent by the customer
BufferedImage-The way Java loads an image into memory is
getWidth/getHeight-is to get the width and height of the picture
图片的高度或者宽度 0 那么后面的业务不执行 (可能是病毒)
3-Implement sub-directory storage
String dateDirPath = new SimpleDateFormat("/yyyy/MM/dd/").format(new Date());
//文件存储的目录 E:/Tmooc_image/2021/01/26/
String fileDirPath = localDirPath + dateDirPath;
File fileDir = new File(fileDirPath);
if(!fileDir.exists()){
//判断文件目录是否存在
fileDir.mkdirs(); //创建目录
}
SimpleDateFormat —— date format (M month d day in y year)
format —— format time (current time shall prevail)
localDirPath + dateDirPath —— spliced image storage path and time (E:/Tmooc_image/2021/01/26)
File-Create a folder based on the path and time of the picture
图片存储路径和时间拼接成新的路径，如果文件夹不存在的话创建一个，如果存在的话执行下一个业务
4-Use UUID to dynamically generate picture name
String uuid = UUID.randomUUID().toString().replace("-", "");
String Filetype = filename.substring(filename.lastIndexOf("."));
String newFileName = uuid + Filetype;
UUID-automatic code generator
randomUUID —— Randomly generate code
toString —— the form of encoding into a string
replace —— replace the characters in the string (- replace empty)
substring-defines where the string starts
filename.lastIndexOf(".") —— Defines starting from the point of the picture name Li Mina (.jpg)
uuid + Filetype —— The type of picture stitched with uuid encoding (absadfa.jpg)
好多的图片名字是相同 为了这个我们使用UUID来编码出字符串，然后获取图片的后缀 最后拼接UUID和后缀做出新的图片名称
5-Realize image upload
File realFile = new File(fileDirpath + newFileName);
uploadFile.transferTo(realFile);
fileDirpath + newFileName —— The address of the image storage and the name of the stored image
transferTo —— The image sent by the client is stored
存储的目录，文件夹，图片名称都有了 我们把这些拼接并且进行存储到磁盘中
6-Edit the path of the picture
String url = urlPath + dateDirpath + newFileName;
return ImageVO.success(url, whdth, height);