最近在学习SpringBoot，以下是最近学习整理的实现文件上传下载的Java代码：

1、开发环境：

IDEA15+ Maven+JDK1.8

2、新建一个maven工程：

3、工程框架

4、pom.xml文件依赖项

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>SpringWebContent</groupId> <artifactId>SpringWebContent</artifactId> <packaging>war</packaging> <version>1.0-SNAPSHOT</version> <name>SpringWebContent Maven Webapp</name> <url>http://maven.apache.org</url> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.3.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> </dependencies> <properties> <java.version>1.8</java.version> </properties> <build> <finalName>SpringWebContent</finalName> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin></plugins> </build></project>

5、Application.java

import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicationpublic class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); }}

6、FileController.java

import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestParam;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.web.bind.annotation.ResponseBody;import org.springframework.web.multipart.MultipartFile;import org.springframework.web.multipart.MultipartHttpServletRequest;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.*;import java.util.List;@Controllerpublic class FileController { @RequestMapping("/greeting") public String greeting(@RequestParam(value="name", required=false, defaultValue="World") String name, Model model) { model.addAttribute("name", name); return "greeting"; } private static final Logger logger = LoggerFactory.getLogger(FileController.class); //文件上传相关代码 @RequestMapping(value = "upload") @ResponseBody public String upload(@RequestParam("test") MultipartFile file) { if (file.isEmpty()) { return "文件为空"; } // 获取文件名 String fileName = file.getOriginalFilename(); logger.info("上传的文件名为：" + fileName); // 获取文件的后缀名 String suffixName = fileName.substring(fileName.lastIndexOf(".")); logger.info("上传的后缀名为：" + suffixName); // 文件上传后的路径 String filePath = "E://test//"; // 解决中文问题，liunx下中文路径，图片显示问题 // fileName = UUID.randomUUID() + suffixName; File dest = new File(filePath + fileName); // 检测是否存在目录 if (!dest.getParentFile().exists()) { dest.getParentFile().mkdirs(); } try { file.transferTo(dest); return "上传成功"; } catch (IllegalStateException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return "上传失败"; } //文件下载相关代码 @RequestMapping("/download") public String downloadFile(org.apache.catalina.servlet4preview.http.HttpServletRequest request, HttpServletResponse response){ String fileName = "FileUploadTests.java"; if (fileName != null) { //当前是从该工程的WEB-INF//File//下获取文件(该目录可以在下面一行代码配置)然后下载到C:\\users\\downloads即本机的默认下载的目录 String realPath = request.getServletContext().getRealPath( "//WEB-INF//"); File file = new File(realPath, fileName); if (file.exists()) { response.setContentType("application/force-download");// 设置强制下载不打开 response.addHeader("Content-Disposition", "attachment;fileName=" + fileName);// 设置文件名 byte[] buffer = new byte[1024]; FileInputStream fis = null; BufferedInputStream bis = null; try { fis = new FileInputStream(file); bis = new BufferedInputStream(fis); OutputStream os = response.getOutputStream(); int i = bis.read(buffer); while (i != -1) { os.write(buffer, 0, i); i = bis.read(buffer); } System.out.println("success"); } catch (Exception e) { e.printStackTrace(); } finally { if (bis != null) { try { bis.close(); } catch (IOException e) { e.printStackTrace(); } } if (fis != null) { try { fis.close(); } catch (IOException e) { e.printStackTrace(); } } } } } return null; } //多文件上传 @RequestMapping(value = "/batch/upload", method = RequestMethod.POST) @ResponseBody public String handleFileUpload(HttpServletRequest request) { List<MultipartFile> files = ((MultipartHttpServletRequest) request) .getFiles("file"); MultipartFile file = null; BufferedOutputStream stream = null; for (int i = 0; i < files.size(); ++i) { file = files.get(i); if (!file.isEmpty()) { try { byte[] bytes = file.getBytes(); stream = new BufferedOutputStream(new FileOutputStream( new File(file.getOriginalFilename()))); stream.write(bytes); stream.close(); } catch (Exception e) { stream = null; return "You failed to upload " + i + " => " + e.getMessage(); } } else { return "You failed to upload " + i + " because the file was empty."; } } return "upload successful"; }

7、index.html

<!DOCTYPE html><html lang="en"><head> <title>Getting Started: Serving Web Content</title> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /></head><body><p>Get your greeting <a href="/greeting" rel="external nofollow" >here</a></p><form action="/upload" method="POST" enctype="multipart/form-data"> 文件：<input type="file" name="test"/> <input type="submit" /></form><a href="/download" rel="external nofollow" >下载test</a><p>多文件上传</p><form method="POST" enctype="multipart/form-data" action="/batch/upload"> <p>文件1：<input type="file" name="file" /></p> <p>文件2：<input type="file" name="file" /></p> <p><input type="submit" value="上传" /></p></form></html>

完整工程地址：SpringWebContent_jb51.rar

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。