大文件下载防内存溢出简单实现

摘要：利用StreamingResponseBody来防止内存溢出，实现大文件下载。

一、配置异步请求超时时间

 1 /**
 2  * @Description: 异步请求配置类
 3  * @Date: Created in 17:19 2025/1/5
 4  * @Author: Cenobitor
 5  * @Modified By:
 6  * @since 0.1.0
 7  */
 8 @Configuration
 9 @EnableWebMvc
10 public class WebConfig implements WebMvcConfigurer {
11 
12     @Override
13     public void configureAsyncSupport(AsyncSupportConfigurer configurer) {
14         configurer.setTaskExecutor(taskExecutor());
15         // 超时时间设置为6000s
16         configurer.setDefaultTimeout(TimeUnit.SECONDS.toMillis(6000));
17     }
18 
19     private AsyncTaskExecutor taskExecutor() {
20         ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
21         executor.setCorePoolSize(10); // 核心线程数
22         executor.setMaxPoolSize(20);  // 最大线程数
23         executor.setQueueCapacity(500); // 队列容量
24         executor.setThreadNamePrefix("Async-");
25         executor.initialize();
26         return executor;
27     }
28 }

二、本地、远程文件下载请求接口

 1  @RequestMapping( "/downloadFile")
 2     public ResponseEntity<StreamingResponseBody> downloadFile() {
 3         long start = System.currentTimeMillis();
 4         try {
 5             Path filePath = Paths.get("E:\\macOS Catalina 10.15 正式版 19A583 macOShome.com.dmg");
 6             StreamingResponseBody responseBody = outputStream -> {
 7                 try (InputStream inputStream = Files.newInputStream(filePath)) {
 8                     StreamUtils.copy(inputStream, outputStream);
 9                 }
10             };
11             HttpHeaders header = new HttpHeaders();
12             header.setContentDispositionFormData("attachment", "macOS.dmg");
13             header.setContentType(MediaType.APPLICATION_OCTET_STREAM);
14             return new ResponseEntity<>(responseBody,header, HttpStatus.OK);
15         } catch (Exception e) {
16             throw new RuntimeException(e);
17         } finally {
18             long end = System.currentTimeMillis();
19             System.out.println("downloadFile cost: " + (end - start) + "ms");
20         }
21     }
22 
23     @RequestMapping( "/downloadRemoteFile")
24     public ResponseEntity<StreamingResponseBody> downloadRemoteFile() {
25         long start = System.currentTimeMillis();
26         try {
27             StreamingResponseBody responseBody = outputStream -> {
28                 URL resourceUrl = new URL("https://cdn.mysql.com/Downloads/MySQL-9.1/mysql-9.1.0-winx64-debug-test.zip");
29                 try (InputStream inputStream = new UrlResource(resourceUrl).getInputStream()) {
30                     StreamUtils.copy(inputStream, outputStream);
31                 }
32             };
33             HttpHeaders header = new HttpHeaders();
34             header.setContentDispositionFormData("attachment", "mysql.zip");
35             header.setContentType(MediaType.APPLICATION_OCTET_STREAM);
36             return new ResponseEntity<>(responseBody,header, HttpStatus.OK);
37         } catch (Exception e) {
38             throw new RuntimeException(e);
39         } finally {
40             long end = System.currentTimeMillis();
41             System.out.println("downloadFile cost: " + (end - start) + "ms");
42         }
43     }

三、前端页面代码

 1 <template>
 2   <div class="download-wrap">
 3     <el-button type="primary" icon="el-icon-download" size="sm>ll" @click="downloadFile">下载文件</el-button>
 4     <el-button type="primary" icon="el-icon-download" size="sm>ll" @click="downloadRemoteFile">下载远程文件</el-button>
 5   </div>
 6 </template>
 7 
 8 <script>
 9 import axios from "axios";
10 
11 export default {
12   name: 'HelloWorld',
13   props: {
14     msg: String
15   },
16 
17   methods:{
18     downloadFile() {
19       console.log('下载文件开始');
20       const downloadUrl = 'http://localhost:8080/downloadFile'; // 文件下载的链接
21       window.open(downloadUrl);
22       console.log('下载文件完成');
23     },
24     downloadRemoteFile() {
25       console.log('下载文件开始');
26       const downloadUrl = 'http://localhost:8080/downloadRemoteFile'; // 文件下载的链接
27       window.open(downloadUrl);
28       console.log('下载文件完成');
29     },
30   },
31   mounted() {
32     axios.get('http://localhost:8080/hello').then(res => {
33       console.log(res);
34     });
35   },
36 }
37 </script>