spring-boot+layui 实现预览word、excel

实现预览 Word、Excel 文件可以通过以下步骤：

1. 在 Spring Boot 中添加 Maven 依赖：

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.2</version>
</dependency>

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

2. 创建一个 Controller 类，提供文件预览的接口。

@RestController
public class FilePreviewController {
    @GetMapping("/preview")
    public void previewFile(HttpServletResponse response,
                            @RequestParam(name = "filePath") String filePath) throws IOException {
        File file = new File(filePath);
        if (!file.exists()) {
            throw new FileNotFoundException();
        }

        String fileName = file.getName();
        String extension = FilenameUtils.getExtension(fileName).toLowerCase();
        InputStream inputStream = new FileInputStream(file);

        response.setHeader("Content-Disposition", "inline;filename=" + fileName);
        response.setContentType(getContentType(extension));
        IOUtils.copy(inputStream, response.getOutputStream());
        response.flushBuffer();
    }

    private String getContentType(String extension) {
        switch (extension) {
            case "doc":
                return "application/msword";
            case "docx":
                return "application/vnd.openxmlformats-officedocument.wordprocessingml.document";
            case "xls":
                return "application/vnd.ms-excel";
            case "xlsx":
                return "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
            default:
                return "application/octet-stream";
        }
    }
}

3. 在 HTML 页面中调用接口，使用 Layui 的 iframe 模块显示文件预览。

<div class="layui-col-md6">
    <div class="layui-card">
        <div class="layui-card-header">文件预览</div>
        <div class="layui-card-body">
            <div class="layui-btn-group">
                <button class="layui-btn layui-btn-warm" onclick="previewFile('doc')">预览 Word</button>
                <button class="layui-btn layui-btn-warm" onclick="previewFile('xls')">预览 Excel</button>
            </div>
            <div class="layui-col-md12">
                <iframe id="previewIframe" frameborder="0" style="width: 100%;height: 600px;"></iframe>
            </div>
        </div>
    </div>
</div>
<script>
    function previewFile(extension) {
        let filePath = "/preview?filePath=" + encodeURIComponent("path/to/file." + extension);
        $("#previewIframe").attr("src", filePath);
    }
</script>

这样就可以实现 Word、Excel 文件的预览了。注意，以上示例仅供参考，具体实现方式需要根据实际情况进行调整。