Spring Boot 集成 SFTP 文件上传和下载功能

Bertha 。 2022-12-13 01:43 859阅读 0赞

### 文章目录 ###

*   *   *  1 摘要
         *  2 核心 Maven 依赖
         *  3 核心代码
         *   *  3.1 核心 SFTP 上传下载工具类
             *  3.2 SFTP 附件上传配置
             *  3.3 SFTP 附件上传与下载示例
         *  4 测试
         *  5 推荐参考资料
         *  6 Github 源码

### 1 摘要 ###

在项目中附件上传和下载是一个常用的功能。可采用的方案有三种，第一种，将附件保存至应用服务器上，这一种应对少量不重要附件可以使用，但对于大量附件或者有重要附件的，不建议使用；第二种，将附件保存至专门的文件服务器上，这一种可应对大量、重要的附件，但是需要自行架设大存储空间的服务器；第三种保存至类似阿里云的 OSS 的服务器上，这一种也可以应对大批量、重要的附件，不过租用第三方服务器也需要付费。本文将介绍第二种，在Spring Boot 项目中通过 SFTP 的方式上传和下载附件。

### 2 核心 Maven 依赖 ###

./demo-common/pom.xml

<dependency>
                <groupId>com.jcraft</groupId>
                <artifactId>jsch</artifactId>
                <version>${jsch.version}</version>
            </dependency>

其中 `${jsch.version}` 的版本为 `0.1.55`

### 3 核心代码 ###

#### 3.1 核心 SFTP 上传下载工具类 ####

./demo-common/src/main/java/com/ljq/demo/springboot/common/util/SftpUtil.java

package com.ljq.demo.springboot.common.util;
    
    import com.jcraft.jsch.*;
    import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.Objects;
    import java.util.Properties;
    
    /** * @Description: sftp 工具类 * @Author: junqiang.lu * @Date: 2020/9/23 */
    public class SftpUtil { 
    
        private SftpUtil() { 
        }
    
        /** * 每个目录下最大子文件(夹)数量 */
        private static final int MAX_CHILD_FILE_NUMBER = 1000;
        private static volatile ChannelSftp sftp = null;
        private static volatile Session sshSession = null;
    
        /** * 附件上传 * * @param sftpConfig sftp 配置信息 * @param fileName 文件名 * @param inputStream 文件流 * @return * @throws SftpException * @throws JSchException */
        public static String upload(SftpConfig sftpConfig, String fileName, InputStream inputStream) throws SftpException, JSchException { 
            return upload(sftpConfig,null, fileName, inputStream);
        }
    
        /** * 文件上传 * * @param sftpConfig sftp 配置信息 * @param relativePath 文件保存的相对路径(最后一级目录) * @param fileName 文件名 * @param inputStream 文件流 * @return * @throws JSchException * @throws SftpException */
        public static String upload(SftpConfig sftpConfig, String relativePath, String fileName, InputStream inputStream)
                throws JSchException, SftpException { 
            init(sftpConfig);
            createFolder(sftpConfig.getPath());
            String filePath = sftpConfig.getPath();
            if (relativePath != null && !relativePath.trim().isEmpty()) { 
                filePath = sftpConfig.getPath() + "/" + relativePath;
            }
            filePath = generateValidPath(filePath);
            filePath = filePath + "/" + fileName;
            sftp.put(inputStream, filePath);
            return filePath.substring(sftpConfig.getPath().length() + 1);
        }
    
        /** * 文件下载 * * @param sftpConfig sftp 配置信息 * @param fileName * @return * @throws JSchException * @throws SftpException */
        public static byte[] download(SftpConfig sftpConfig, String fileName) throws JSchException, SftpException,
                IOException { 
            init(sftpConfig);
            InputStream inputStream = sftp.get(sftpConfig.getPath() + "/" + fileName);
            ByteArrayOutputStream buffer = new ByteArrayOutputStream();
            int n;
            byte[] data = new byte[1024];
            while ((n = inputStream.read(data, 0, data.length)) != -1) { 
                buffer.write(data, 0, n);
            }
            buffer.flush();
            return buffer.toByteArray();
        }
    
        /** * 判断是否关闭 * * @return */
        public static boolean isClosed() { 
            if (Objects.isNull(sshSession) || Objects.isNull(sftp)) { 
                return false;
            }
            if (Objects.nonNull(sshSession) && sshSession.isConnected() && Objects.nonNull(sftp) && sftp.isConnected()) { 
                return true;
            }
            return false;
        }
    
        /** * 关闭 */
        public static void close(){ 
            if (sshSession != null && sshSession.isConnected()) { 
                sshSession.disconnect();
            }
            if (sftp != null && sftp.isConnected()) { 
                sftp.disconnect();
            }
        }
    
        /** * 初始化 * * @throws JSchException */
        private static void init(SftpConfig sftpConfig) throws JSchException { 
            if (!isClosed()) { 
                synchronized (SftpUtil.class) { 
                    if (!isClosed()) { 
                        JSch jsch = new JSch();
                        jsch.getSession(sftpConfig.getUsername(), sftpConfig.getHost(), sftpConfig.getPort());
                        sshSession = jsch.getSession(sftpConfig.getUsername(), sftpConfig.getHost(), sftpConfig.getPort());
                        sshSession.setPassword(sftpConfig.getPassword());
                        Properties sshConfig = new Properties();
                        sshConfig.put("StrictHostKeyChecking", "no");
                        sshSession.setConfig(sshConfig);
                        sshSession.connect();
                        Channel channel = sshSession.openChannel("sftp");
                        channel.connect();
                        sftp = (ChannelSftp) channel;
                    }
                }
            }
        }
    
        /** * 创建目录 * * @param path 目录路径 * @return */
        private static boolean createFolder(String path) { 
            try { 
                sftp.mkdir(path);
            } catch (SftpException e) { 
                return false;
            }
            return true;
        }
    
        /** * 统计目录下文件(夹)数量 * * @param path * @return */
        private static int countFiles(String path) throws SftpException { 
            sftp.cd(path);
            return sftp.ls(path).size();
        }
    
        /** * 校验路径是否可用 * * @param path * @return */
        private static boolean validatePathValid(String path) { 
            int countFiles = 0;
            try { 
                countFiles = countFiles(path);
            } catch (SftpException e) { 
                createFolder(path);
            }
            if (countFiles <= MAX_CHILD_FILE_NUMBER) { 
                return true;
            }
            return false;
        }
    
        /** * 生成有效路径 * * @param path * @return */
        private static String generateValidPath(String path) { 
            if (validatePathValid(path)) { 
                return path;
            } else { 
                String newPath = path + String.valueOf(System.currentTimeMillis()).substring(9);
                createFolder(newPath);
                return newPath;
            }
        }
    
        /** * sftp 配置信息 */
        @Data
        @NoArgsConstructor
        @AllArgsConstructor
        public class SftpConfig { 
            /** * 主机地址 */
            private String host;
            /** * sftp 连接端口 */
            private int port;
            /** * 用户名 */
            private String username;
            /** * 密码 */
            private String password;
            /** * 文件保存根路径 */
            private String path;
    
        }
    
        public static SftpConfig sftpConfig() { 
            return new SftpUtil().new SftpConfig();
        }
    
        public static SftpConfig sftpConfig(String host, int port, String username, String password, String path) { 
            return new SftpUtil().new SftpConfig(host, port, username, password, path);
        }
    
    
    
    }

#### 3.2 SFTP 附件上传配置 ####

SFTP 配置类

./demo-base-web/src/main/java/com/ljq/demo/springboot/baseweb/config/SftpUploadConfig.java

package com.ljq.demo.springboot.baseweb.config;
    
    import lombok.Getter;
    import lombok.ToString;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Configuration;
    
    /** * @Description: sftp 附件上传配置 * @Author: junqiang.lu * @Date: 2020/9/27 */
    @ToString
    @Getter
    @Configuration
    public class SftpUploadConfig { 
    
        /** * 主机地址 */
        @Value("${uploadSftp.host}")
        private String host;
        /** * sftp 连接端口 */
        @Value("${uploadSftp.port}")
        private int port;
        /** * 用户名 */
        @Value("${uploadSftp.username}")
        private String username;
        /** * 密码 */
        @Value("${uploadSftp.password}")
        private String password;
        /** * 文件保存路径 */
        @Value("${uploadSftp.path}")
        private String path;
    
    
    
    }

SFTP 配置信息

./demo-web/src/main/resources/application-dev.yml
    ./demo-web/src/main/resources/application-test.yml
    ./demo-web/src/main/resources/application-pro.yml

## sftp 附件上传配置
    uploadSftp:
      host: 172.16.140.10
      port: 22
      username: root
      password: root
      path: /home/ljq/upload

#### 3.3 SFTP 附件上传与下载示例 ####

Service 层

Service 接口:

./demo-service/src/main/java/com/ljq/demo/springboot/service/CommonService.java

package com.ljq.demo.springboot.service;
    
    import com.jcraft.jsch.JSchException;
    import com.jcraft.jsch.SftpException;
    import com.ljq.demo.springboot.baseweb.api.ApiResult;
    import com.ljq.demo.springboot.baseweb.exception.ParamsCheckException;
    import com.ljq.demo.springboot.vo.DownloadBean;
    import org.springframework.http.ResponseEntity;
    import org.springframework.web.multipart.MultipartFile;
    
    import java.io.IOException;
    
    /** * @Description: 公共业务 * @Author: junqiang.lu * @Date: 2018/12/24 */
    public interface CommonService { 
    
        /** * 通过 sftp 上传附件至固定服务器 * * @param file 文件 * @param dir 文件夹名称 * @return * @throws ParamsCheckException */
        ApiResult uploadSftp(MultipartFile file, String dir) throws ParamsCheckException;
    
        /** * * 通过 sftp 下载文件 * * @param filePath 文件路径 * @return * @throws JSchException * @throws SftpException * @throws IOException */
        ResponseEntity<byte[]> downloadSftp(String filePath) throws JSchException, SftpException, IOException;
    
    
    }

Service 实现类:

./demo-service/src/main/java/com/ljq/demo/springboot/service/impl/CommonServiceImpl.java

package com.ljq.demo.springboot.service.impl;
    
    import cn.hutool.core.bean.BeanUtil;
    import cn.hutool.core.bean.copier.CopyOptions;
    import cn.hutool.core.util.StrUtil;
    import com.jcraft.jsch.JSchException;
    import com.jcraft.jsch.SftpException;
    import com.ljq.demo.springboot.baseweb.api.ApiResult;
    import com.ljq.demo.springboot.baseweb.api.ResponseCode;
    import com.ljq.demo.springboot.baseweb.config.OSSConfig;
    import com.ljq.demo.springboot.baseweb.config.PDFExportConfig;
    import com.ljq.demo.springboot.baseweb.config.SftpUploadConfig;
    import com.ljq.demo.springboot.baseweb.exception.ParamsCheckException;
    import com.ljq.demo.springboot.baseweb.util.OSSBootUtil;
    import com.ljq.demo.springboot.baseweb.util.OSSSingleUtil;
    import com.ljq.demo.springboot.baseweb.util.PDFUtil;
    import com.ljq.demo.springboot.baseweb.util.ResourceFileUtil;
    import com.ljq.demo.springboot.common.util.SftpUtil;
    import com.ljq.demo.springboot.service.CommonService;
    import com.ljq.demo.springboot.vo.DownloadBean;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.http.HttpHeaders;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.MediaType;
    import org.springframework.http.ResponseEntity;
    import org.springframework.stereotype.Service;
    import org.springframework.web.multipart.MultipartFile;
    
    import java.io.IOException;
    import java.util.Date;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.Objects;
    
    /** * @Description: 公共业务具体实现类 * @Author: junqiang.lu * @Date: 2018/12/24 */
    @Slf4j
    @Service("commonService")
    public class CommonServiceImpl implements CommonService { 
    
        @Autowired
        private PDFExportConfig pdfExportConfig;
        @Autowired
        private OSSConfig ossConfig;
        @Autowired
        private SftpUploadConfig uploadConfig;
    
        /** * 通过 sftp 上传附件至固定服务器 * * @param file 文件 * @param dir 文件夹名称 * @return * @throws ParamsCheckException */
        @Override
        public ApiResult uploadSftp(MultipartFile file, String dir) throws ParamsCheckException { 
            if (Objects.isNull(file) || file.isEmpty()) { 
                throw new ParamsCheckException(ResponseCode.MISS_REQUEST_PART_ERROR);
            }
            log.debug("原始文件名:{},文件大小: {} Mb", file.getOriginalFilename(), (file.getSize()/1048576));
            // 储存文件
            SftpUtil.SftpConfig sftpConfig = SftpUtil.sftpConfig();
            BeanUtil.copyProperties(uploadConfig, sftpConfig, CopyOptions.create().ignoreNullValue().ignoreError());
            String filePath;
            if (StrUtil.isNotBlank(dir)) { 
                dir = dir.replaceAll("[^a-zA-Z0-9]", "");
            }
            try { 
                filePath = SftpUtil.upload(sftpConfig,dir, System.currentTimeMillis() +
                        file.getOriginalFilename(), file.getInputStream());
            } catch (Exception e) { 
                log.warn("文件上传失败,{}", e.getMessage());
                throw new ParamsCheckException(ResponseCode.FAIL);
            }
            return ApiResult.success(filePath);
        }
    
        /** * 通过 sftp 下载文件 * * @param filePath 文件路径 * @return * @throws JSchException * @throws SftpException * @throws IOException */
        @Override
        public ResponseEntity<byte[]> downloadSftp(String filePath) throws JSchException, SftpException, IOException { 
            SftpUtil.SftpConfig sftpConfig = SftpUtil.sftpConfig();
            BeanUtil.copyProperties(uploadConfig, sftpConfig, CopyOptions.create().ignoreNullValue().ignoreError());
            byte[] bytes = SftpUtil.download(sftpConfig, filePath);
            HttpHeaders headers = new HttpHeaders();
            String fileName = filePath.substring(filePath.lastIndexOf("/") + 1);
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
            headers.setContentDispositionFormData("attachment", new String(fileName.getBytes("UTF-8"),"ISO-8859-1"));
            return new ResponseEntity<>(bytes, headers, HttpStatus.OK);
        }
    }

Controller 层:

./demo-web/src/main/java/com/ljq/demo/springboot/web/controller/CommonController.java

package com.ljq.demo.springboot.web.controller;
    
    import com.jcraft.jsch.JSchException;
    import com.jcraft.jsch.SftpException;
    import com.ljq.demo.springboot.baseweb.api.ApiResult;
    import com.ljq.demo.springboot.baseweb.exception.ParamsCheckException;
    import com.ljq.demo.springboot.common.annotation.ParamsCheck;
    import com.ljq.demo.springboot.service.CommonService;
    import com.ljq.demo.springboot.vo.DownloadBean;
    import io.swagger.annotations.ApiOperation;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.http.HttpHeaders;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.MediaType;
    import org.springframework.http.ResponseEntity;
    import org.springframework.web.bind.annotation.*;
    import org.springframework.web.multipart.MultipartFile;
    
    import java.io.IOException;
    
    /** * @Description: 公共模块控制中心 * @Author: junqiang.lu * @Date: 2018/12/24 */
    @RestController
    @RequestMapping("api/demo/common")
    public class CommonController { 
    
        private static final Logger logger = LoggerFactory.getLogger(CommonController.class);
    
        @Autowired
        private CommonService commonService;
    
        /** * 通过 sftp 上传附件至固定服务器 * * @param file 文件 * @param dir 文件夹名称 * @return * @throws ParamsCheckException */
        @PostMapping(value = "/upload/sftp", produces = { MediaType.APPLICATION_JSON_VALUE})
        @ApiOperation(value = "文件上传", notes = "文件上传")
        public ResponseEntity<ApiResult> uploadSftp(@RequestParam("file") MultipartFile file,
                                                String dir) throws ParamsCheckException { 
            ApiResult apiResult = commonService.uploadSftp(file, dir);
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_JSON);
            return new ResponseEntity<>(apiResult, headers, HttpStatus.OK);
        }
    
        /** * 通过 sftp 下载文件 * * @param filePath 文件路径 * @return * @throws JSchException * @throws SftpException * @throws IOException */
        @ParamsCheck(ignore = true)
        @GetMapping(value = "/download/sftp", produces = { MediaType.MULTIPART_FORM_DATA_VALUE})
        public ResponseEntity<byte[]> downloadSftp(String filePath) throws JSchException, SftpException, IOException { 
            ResponseEntity<byte[]> responseEntity = commonService.downloadSftp(filePath);
            return responseEntity;
        }
    
    }

### 4 测试 ###

上传:

![上传][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L01ycWlhbmc5MDAx_size_16_color_FFFFFF_t_70_pic_center]

下载:  
![下载][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L01ycWlhbmc5MDAx_size_16_color_FFFFFF_t_70_pic_center 1]

### 5 推荐参考资料 ###

[JAVA SFTP文件上传、下载及批量下载][JAVA SFTP]

[Java InputStream to Byte Array and ByteBuffer][]

[Java – Write to File][Java _ Write to File]

### 6 Github 源码 ###

**Gtihub 源码地址** : [https://github.com/Flying9001/springBootDemo][https_github.com_Flying9001_springBootDemo]

个人公众号:**404Code**,分享半个互联网人的技术与思考，感兴趣的可以关注.  
![404Code][]

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[JAVA SFTP]: https://www.cnblogs.com/foxting/p/10248105.html
[Java InputStream to Byte Array and ByteBuffer]: https://www.baeldung.com/convert-input-stream-to-array-of-bytes
[Java _ Write to File]: https://www.baeldung.com/java-write-to-file
[https_github.com_Flying9001_springBootDemo]: https://github.com/Flying9001/springBootDemo
[404Code]: /images/20221123/accd7aeb12c645b595d9a7ba28fc3b6c.png