[JAVA] File upload with Spring Boot

Implement as the title of the article. The following functions will be implemented this time. -Upload by specifying the image path from the input screen composed of HTML form and input tag -Output the file to the specified directory via Java

File to modify

Modify the following 3 files

Controller

`java:com.example.SampleController.java`


@RequestMapping(path = "/sample/upload", method = RequestMethod.GET)
String uploadview(Model model) {
  return "sample/upload";
}

@RequestMapping(path = "/sample/upload", method = RequestMethod.POST)
String upload(Model model, UploadForm uploadForm) {
  if (uploadForm.getFile().isEmpty()) {
    return "sample/upload";
  }

  // check upload distination directory.If there was no directory, make
  // func.
  Path path = Paths.get("/Users/demo-kusa/image");
  if (!Files.exists(path)) {
    try {
      Files.createDirectory(path);
    } catch (NoSuchFileException ex) {
      System.err.println(ex);
    } catch (IOException ex) {
      System.err.println(ex);
    }
  }

  int dot = uploadForm.getFile().getOriginalFilename().lastIndexOf(".");
  String extention = "";
  if (dot > 0) {
    extention = uploadForm.getFile().getOriginalFilename().substring(dot).toLowerCase();
  }
  String filename = DateTimeFormatter.ofPattern("yyyyMMddHHmmssSSS").format(LocalDateTime.now());
  Path uploadfile = Paths
      .get("/Users/demo-kusa/image/" + filename + extention);

  try (OutputStream os = Files.newOutputStream(uploadfile, StandardOpenOption.CREATE)) {
    byte[] bytes = uploadForm.getFile().getBytes();
    os.write(bytes);
  } catch (IOException ex) {
    System.err.println(ex);
  }

  return "redirect:/sample";
}

ActionForm

`java:com.example.UploadForm.java`


package com.example;

import org.springframework.web.multipart.MultipartFile;
public class UploadForm {
  private MultipartFile file;

  public MultipartFile getFile() {
    return file;
  }

  public void setFile(MultipartFile file) {
    this.file = file;
  }
}

template

`src/main/resources/templates/sample/upload.html`


<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<title>top page</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<h2>Image upload</h2>
    <form method="post" enctype="multipart/form-data" action="/sample/upload" >
        <input name="file" type="file" />
        <input type="submit" value="Send"/>
    </form>
</body>
</html>

This article has partially replaced the environment-dependent part, but the source is below, so if you need it, please. github kaikusakari/spring_crud