springboot 上传图片与回显

　　在网上找了很多例子，不能完全契合自己的需求，自行整理了下。需求是这样的：项目小，所以不需要单独的图片服务器，图片保存在服务器中任意的地方，并且可以通过访问服务器来获取图片。话不多说上代码：

1、依赖

                <dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-thymeleaf</artifactId>
		</dependency>
		<!-- apache.commons -->
		<dependency>
			<groupId>commons-lang</groupId>
			<artifactId>commons-lang</artifactId>
			<version>2.6</version>
			<scope>provided</scope>
		</dependency>
		<dependency>
		    <groupId>org.apache.commons</groupId>
		    <artifactId>commons-io</artifactId>
		    <version>1.3.2</version>
		</dependency>

2、文件上传工具类

package com.slovi.utils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;
import org.springframework.web.multipart.MultipartFile;

public class FileUpload {

	/**
	 * 文件上传处理
	 *
	 * @param file
	 * @return
	 */
	public static String writeUploadFile(MultipartFile file,String module) {
		String filename = file.getOriginalFilename();
		String realpath = "D:/rentHouse/" +  module +"/";
		File fileDir = new File(realpath);
		if (!fileDir.exists())
			fileDir.mkdirs();

		String extname = FilenameUtils.getExtension(filename);
		String allowImgFormat = "gif,jpg,jpeg,png";
		if (!allowImgFormat.contains(extname.toLowerCase())) {
			return "NOT_IMAGE";
		}

		filename = Math.abs(file.getOriginalFilename().hashCode()) + RandomUtils.createRandomString( 4 ) + "." + extname;
		InputStream input = null;
		FileOutputStream fos = null;
		try {
			input = file.getInputStream();
			fos = new FileOutputStream(realpath + "/" + filename);
			IOUtils.copy(input, fos);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		} finally {
			IOUtils.closeQuietly(input);
			IOUtils.closeQuietly(fos);
		}
		return "/" + filename;
	}
}

3、随机数生成工具类

package com.slovi.utils;

public class RandomUtils {

	private static final String charlist = "0123456789";

	public static String createRandomString(int len) {
		String str = new String();
		for (int i = 0; i < len; i++) {
			str += charlist.charAt(getRandom(charlist.length()));
		}
		return str;
	}

	public static int getRandom(int mod) {
		if (mod < 1) {
			return 0;
		}
		int ret = getInt() % mod;
		return ret;
	}

	private static int getInt() {
		int ret = Math.abs(Long.valueOf(getRandomNumString()).intValue());
		return ret;
	}

	private static String getRandomNumString() {
		double d = Math.random();
		String dStr = String.valueOf(d).replaceAll("[^\\d]", "");
		if (dStr.length() > 1) {
			dStr = dStr.substring(0, dStr.length() - 1);
		}
		return dStr;
	}
}

4、控制类

package com.slovi.controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import com.slovi.utils.FileUpload;

@RestController
@RequestMapping("/Advert")
public class AdvertController {

	@Autowired
	private AdvertInfoService advertInfoService;

	@PostMapping("/upload")
	public Object upload(@RequestParam("file") MultipartFile  file) {

		String filename = FileUpload.writeUploadFile(file,"advert");
                return filename;

	}

}

5、配置类

package com.slovi.config;

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

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
        registry.addResourceHandler("/advertIMG/**").addResourceLocations("file:D:/rentHouse/");
    } 

}

6、测试页面，放到resources/templates包下

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8"/>
    <title>Title</title>
</head>
<body>
<form action="/upload" th:action="@{/upload}" method="post" enctype="multipart/form-data" >
    <label>上传图片</label>
    <input type="file" name="file"/>
    <input type="submit" value="上传"/>
</form>
</body>
</html>

　　启动项目，访问：localhost:8888,进入上传页面，上传成功会返回图片名称，例如：11348371257146.jpg，然后访问http://localhost:8888/advertIMG/11348371257146.jpg,可以获取到图片。