关闭资源： public R<Void> importData(@RequestPart("file") MultipartFile file, boolean updateSupport) throws Exception { ExcelResult<SysUserImportVo> result = ExcelUtil.importExcel(file.getInputStream(), SysUserImportVo.class, new SysUserImportListener(updateSupport)); return R.ok(result.getAnalysis()); }

在这段代码中，输入流是从 MultipartFile 中获取的，需要在使用完毕后关闭。可以使用 try-with-resources 语句块来确保输入流得到关闭。

改进后的代码如下所示：

public R<Void> importData(@RequestPart("file") MultipartFile file, boolean updateSupport) throws Exception {
    try (InputStream inputStream = file.getInputStream()) {
        ExcelResult<SysUserImportVo> result = ExcelUtil.importExcel(inputStream, SysUserImportVo.class, new SysUserImportListener(updateSupport));
        return R.ok(result.getAnalysis());
    }
}

在 try-with-resources 中声明了一个 InputStream 变量，这个变量在 try-with-resources 结束时会自动关闭。这样可以确保输入流被正确关闭，避免资源泄漏的问题。

相关问题

<h1>上传/下载文件</h1> <form method="post" action="/file/upload" enctype="multipart/form-data"> <input type="file" name="file" id="fileInput"/> <input type="submit" value="上传" /> </form> <hr> <form method="post" action="/file/download" > <input type="text" name="fileName" placeholder="请输入文件名" /> <input type="submit" value="下载" id="downloadBtn" /> </form> public class SFTPUtil { private static final String host = "10.60.0.160"; private static final int port = 22; private static final String username = "root"; private static final String password = "Z20"; private static Session session = null; public static void connect() throws Exception { } public static void upload(MultipartFile file, String path, String fileName) throws Exception { } public static boolean download(HttpServletResponse response, String path, String fileName) throws Exception { } @Controller @RequestMapping("/file") public class FileController { private static final String UPLOAD_PATH = "/data/sftp/adtuser1/upload/winbidding/"; private static final String DOWNLOAD_PATH = "/data/sftp/adtuser1/upload/winbidding/"; @PostMapping("/upload") @ResponseBody public ModelAndView upload(@RequestParam("file") MultipartFile file) { } @PostMapping("/download") public ModelAndView download(@RequestParam("fileName") String fileName, HttpServletResponse response) throws Exception { } 数据库有host port username password UPLOAD_PATH DOWNLOAD_PATH csmc字段，把上边写死的改成数据库查询，前台页面增加csmc字段下拉框，根据csmc字段把查出来的配置数据完成上传下载功能，用的mysql数据库，把代码改好写出来

首先需要在数据库中创建一个表，用于存储SFTP连接的相关信息：

CREATE TABLE sftp_config (
  id INT PRIMARY KEY AUTO_INCREMENT,
  csmc VARCHAR(50),
  host VARCHAR(50),
  port INT,
  username VARCHAR(50),
  password VARCHAR(50),
  upload_path VARCHAR(255),
  download_path VARCHAR(255)
);

然后在Spring Boot项目中创建一个SFTPUtil类，用于实现SFTP上传和下载功能：

import com.jcraft.jsch.*;

import org.springframework.web.multipart.MultipartFile;

import java.io.*;
import java.util.Properties;

public class SFTPUtil {

    private String host;
    private int port;
    private String username;
    private String password;
    private String uploadPath;
    private String downloadPath;
    private Session session;

    public SFTPUtil(String host, int port, String username, String password, String uploadPath, String downloadPath) {
        this.host = host;
        this.port = port;
        this.username = username;
        this.password = password;
        this.uploadPath = uploadPath;
        this.downloadPath = downloadPath;
    }

    public void connect() throws Exception {
        JSch jsch = new JSch();
        session = jsch.getSession(username, host, port);
        session.setPassword(password);
        Properties config = new Properties();
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        session.connect();
    }

    public void upload(MultipartFile file, String fileName) throws Exception {
        ChannelSftp channel = (ChannelSftp) session.openChannel("sftp");
        channel.connect();
        channel.cd(uploadPath);
        InputStream inputStream = file.getInputStream();
        channel.put(inputStream, fileName);
        inputStream.close();
        channel.disconnect();
    }

    public boolean download(HttpServletResponse response, String fileName) throws Exception {
        ChannelSftp channel = (ChannelSftp) session.openChannel("sftp");
        channel.connect();
        channel.cd(downloadPath);
        SftpATTRS attrs = channel.lstat(fileName);
        if (attrs == null) {
            channel.disconnect();
            return false;
        }
        response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
        OutputStream outputStream = response.getOutputStream();
        channel.get(fileName, outputStream);
        outputStream.flush();
        outputStream.close();
        channel.disconnect();
        return true;
    }

}

然后在Spring Boot项目中创建一个FileController类，用于处理文件上传和下载请求：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.util.List;
import java.util.Map;

@Controller
@RequestMapping("/file")
public class FileController {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @PostMapping("/upload")
    @ResponseBody
    public String upload(@RequestParam("file") MultipartFile file, @RequestParam("csmc") String csmc) {
        try {
            // 从数据库中获取SFTP连接配置信息
            String sql = "SELECT * FROM sftp_config WHERE csmc = ?";
            Map<String, Object> map = jdbcTemplate.queryForMap(sql, csmc);
            String host = (String) map.get("host");
            int port = (int) map.get("port");
            String username = (String) map.get("username");
            String password = (String) map.get("password");
            String uploadPath = (String) map.get("upload_path");
            String fileName = file.getOriginalFilename();

            // 使用SFTP上传文件
            SFTPUtil sftpUtil = new SFTPUtil(host, port, username, password, uploadPath, null);
            sftpUtil.connect();
            sftpUtil.upload(file, fileName);

            return "上传成功";
        } catch (Exception e) {
            e.printStackTrace();
            return "上传失败";
        }
    }

    @PostMapping("/download")
    public void download(@RequestParam("fileName") String fileName, @RequestParam("csmc") String csmc, HttpServletResponse response) throws Exception {
        // 从数据库中获取SFTP连接配置信息
        String sql = "SELECT * FROM sftp_config WHERE csmc = ?";
        Map<String, Object> map = jdbcTemplate.queryForMap(sql, csmc);
        String host = (String) map.get("host");
        int port = (int) map.get("port");
        String username = (String) map.get("username");
        String password = (String) map.get("password");
        String downloadPath = (String) map.get("download_path");

        // 使用SFTP下载文件
        SFTPUtil sftpUtil = new SFTPUtil(host, port, username, password, null, downloadPath);
        sftpUtil.connect();
        boolean result = sftpUtil.download(response, fileName);
        if (!result) {
            response.getWriter().write("文件不存在");
        }
    }

    @GetMapping("/csmcList")
    @ResponseBody
    public List<String> getCsmcList() {
        // 从数据库中获取所有的csmc字段
        String sql = "SELECT DISTINCT csmc FROM sftp_config";
        List<String> csmcList = jdbcTemplate.queryForList(sql, String.class);
        return csmcList;
    }

}

最后，在HTML页面中加入下面的代码，即可实现文件上传和下载：

<h1>上传/下载文件</h1>
<form method="post" action="/file/upload" enctype="multipart/form-data">
    <input type="file" name="file" id="fileInput"/>
    <select name="csmc" id="csmcSelect"></select>
    <input type="submit" value="上传"/>
</form>
<hr>
<form method="post" action="/file/download">
    <input type="text" name="fileName" placeholder="请输入文件名"/>
    <select name="csmc" id="csmcSelect"></select>
    <input type="submit" value="下载" id="downloadBtn"/>
</form>
<script>
    // 获取csmc列表
    $.get("/file/csmcList", function (data) {
        var csmcSelect = $("#csmcSelect");
        for (var i = 0; i < data.length; i++) {
            var option = $("<option>").val(data[i]).text(data[i]);
            csmcSelect.append(option);
        }
    });
</script>

前端如何调用@RestController @RequestMapping("/excel") public class ImportController { @Resource private ExcelComponent excelComponent; @PostMapping("/import-person") public Boolean importPersonFile(@RequestParam("file") MultipartFile file) throws IOException { excelComponent.importPersonFile(file); return true; }

前端可以通过发送POST请求来调用这个接口。

具体方法如下：

1. 在前端HTML页面中，添加一个文件上传的表单，包含一个文件选择框和一个提交按钮。

2. 当用户选择文件并点击提交按钮时，前端通过JavaScript代码发送一个POST请求到后端的/import-person接口，并将文件数据作为请求参数发送给后端。

3. 后端接收到请求后，调用ExcelComponent组件的importPersonFile方法来处理上传的Excel文件。

4. 处理完成后，后端返回一个布尔值true给前端，表示文件上传成功。

5. 前端可以根据后端返回的结果来进行相应的提示或页面跳转等操作。

示例代码如下：

HTML页面部分：

<form id="uploadForm" method="POST" enctype="multipart/form-data">
  <input type="file" name="file" id="fileInput">
  <button type="submit" id="uploadBtn">上传文件</button>
</form>

JavaScript代码部分：

const form = document.getElementById('uploadForm');
const fileInput = document.getElementById('fileInput');
const uploadBtn = document.getElementById('uploadBtn');

uploadBtn.addEventListener('click', (e) => {
  e.preventDefault();
  
  const formData = new FormData();
  formData.append('file', fileInput.files[0]);
  
  fetch('/excel/import-person', {
    method: 'POST',
    body: formData
  })
  .then(res => res.json())
  .then(data => {
    if (data === true) {
      alert('文件上传成功！');
    } else {
      alert('文件上传失败！');
    }
  })
  .catch(err => {
    console.log(err);
    alert('文件上传失败！');
  });
});