springboot+thymeleaf 实现图片文件上传及回显

1. 创建一个springboot工程, 在此就不多说了(目录结构).

2. 写一个HTML页面

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <link rel="stylesheet" href="../css/bootstrap.css">
    <title>Title</title>
</head>
<body>
    <form action="../upload" method="post" enctype="multipart/form-data">
        <input type="file" name="file" accept="image/*">
        <br>
        <input type="submit" value="上传" class="btn btn-success">
    </form>
    [[${filename}]]
    <br>
    <img th:src="@{${filename}}" alt="图片">
</body>
</html>

3. 配置application.properties文件, 在配置文件中声明图片的绝对路径及相对路径

server.port=8899
file.upload.path=F://images/
file.upload.path.relative=/images/**

4. 创建一个MyWebAppConfigurer java文件实现WebMvcConfigurer接口, 配置资源映射路径

注: 笔者使用的springboot版本为 2.1.6

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * 资源映射路径
 */
@Configuration
public class MyWebAppConfigurer implements WebMvcConfigurer {

    /**上传地址*/
    @Value("${file.upload.path}")
    private String filePath;
    /**显示相对地址*/
    @Value("${file.upload.path.relative}")
    private String fileRelativePath;

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler(fileRelativePath).
                addResourceLocations("file:/" + filePath);
    }
}

5. 编写Controller层

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;

@Controller
public class TestController {

    /**上传地址*/
    @Value("${file.upload.path}")
    private String filePath;

    // 跳转上传页面
    @RequestMapping("test")
    public String test() {
        return "Page";
    }

    // 执行上传
    @RequestMapping("upload")
    public String upload(@RequestParam("file") MultipartFile file, Model model) {
        // 获取上传文件名
        String filename = file.getOriginalFilename();
        // 定义上传文件保存路径
        String path = filePath+"rotPhoto/";
        // 新建文件
        File filepath = new File(path, filename);
        // 判断路径是否存在，如果不存在就创建一个
        if (!filepath.getParentFile().exists()) {
            filepath.getParentFile().mkdirs();
        }
        try {
            // 写入文件
            file.transferTo(new File(path + File.separator + filename));
        } catch (IOException e) {
            e.printStackTrace();
        }
        // 将src路径发送至html页面
        model.addAttribute("filename", "/images/rotPhoto/"+filename);
        return "Page";
    }
}

6. 完成