打开云对象存储上的文档

注意

本文中展示的代码均为关键代码，复制粘贴到您的项目中，按照实际的情况，例如文档路径，用户名等做适当修改即可使用。

某些Web项目中的文档存储采用了云对象存储的方式，比如把Office文档全部保存在阿里云对象存储OSS中，或者文件保存在MinIO，或文件保存在腾讯云COS等对象存储中，那么调用PageOffice在线打开云存储中的Office文件时就需要使用二进制流方式打开。

首先，编写一个下载文件的后台方法读取云对象存储中的Office文件，比如：openStream；

然后，把此openStream方法的url地址传递给PageOfficeCtrl对象的webOpen的第一个参数即可打开；

最后，保存文件时，调用FileSaver对象的getFileBytes()或getFileStream()获取到文件二进制流并保存到云对象存储中。

以打开阿里云对象存储OSS中的Office文件为例：

后端代码

1. 编写下载文件的后台方法读取云对象存储（比如：阿里云OSS）中的Office文件：openStream；

@RequestMapping(value = "openStream", method = RequestMethod.GET)
public void Openstream(HttpServletRequest request, HttpServletResponse response) 
                          throws SQLException, ClassNotFoundException, IOException {

    String fileName = request.getParameter("filename");
    // Endpoint以华东1（杭州）为例，其它Region请按实际情况填写。
    String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
    // 阿里云账号AccessKey。
    String accessKeyId = "yourAccessKeyId";
    String accessKeySecret = "yourAccessKeySecret";
    // 填写Bucket名称，例如examplebucket。
    String bucketName = "examplebucket";
    // 填写Object完整路径，例如exampledir/exampleobject.docx。Object完整路径中不能包含Bucket名称。
    String objectName = "exampledir/" + fileName;

    // 创建OSSClient实例。
    OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);

    try {
        // 调用ossClient.getObject返回一个OSSObject实例，该实例包含文件内容及文件元信息。
        OSSObject ossObject = ossClient.getObject(bucketName, objectName);
        // 调用ossObject.getObjectContent获取文件输入流，可读取此输入流获取其内容。
        InputStream content = ossObject.getObjectContent();
        if (content != null) {
            
            byte[] buffer = new byte[4096];
            int fileSize = 0;
            int byteread = 0;

            response.reset();
            OutputStream outputStream = response.getOutputStream();

            while ((byteread = content.read(buffer)) != -1) {
                fileSize += byteread; //字节数 文件大小
                outputStream.write(buffer, 0, byteread);
            }

            // application/msword, application/x-excel, application/ms-powerpoint, application/pdf
            response.setContentType("application/msword"); 
            response.setHeader("Content-Disposition",
                    "attachment; filename=down.doc"); //fileN应该是编码后的(utf-8)
            response.setContentLength(fileSize);

            outputStream.flush();
            outputStream.close();
            outputStream = null;

            // 数据读取完成后，获取的流必须关闭，否则会造成连接泄漏，导致请求无连接可用，程序无法正常工作。
            content.close();
        }
    } catch (OSSException oe) {
        System.out.println("Caught an OSSException, which means your request made it to OSS, "
                + "but was rejected with an error response for some reason.");
        System.out.println("Error Message:" + oe.getErrorMessage());
        System.out.println("Error Code:" + oe.getErrorCode());
        System.out.println("Request ID:" + oe.getRequestId());
        System.out.println("Host ID:" + oe.getHostId());
    } catch (ClientException ce) {
        System.out.println("Caught an ClientException, which means the client encountered "
                + "a serious internal problem while trying to communicate with OSS, "
                + "such as not being able to access the network.");
        System.out.println("Error Message:" + ce.getMessage());
    } finally {
        if (ossClient != null) {
            ossClient.shutdown();
        }
    }

}

using Aliyun.OSS;
using Aliyun.OSS.Common;

public async Task<IActionResult> OpenStream()
{
    String fileName = Request.Query["filename"];
    // yourEndpoint填写Bucket所在地域对应的Endpoint。以华东1（杭州）为例，Endpoint填写为https://oss-cn-hangzhou.aliyuncs.com。
    var endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
    // 从环境变量中获取访问凭证。运行本代码示例之前，请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
    var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
    var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
    // 填写Bucket名称，例如examplebucket。
    var bucketName = "examplebucket";
    // 填写Object完整路径，完整路径中不能包含Bucket名称，例如exampledir/exampleobject.docx。
    var objectName = "exampledir/" + fileName;

    // 创建OssClient实例。
    var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
    var obj = client.GetObject(bucketName, objectName);

    // 设置响应内容类型为word的内容类型。
    Response.ContentType = "application/msword";
    Response.Headers["Content-Disposition"] = "attachment; filename=" + Path.GetFileName(objectName);
    // 使用流复制的方式将OSS对象的内容输出到响应流中。
    using (var stream = obj.Content)
    {
        await stream.CopyToAsync(Response.Body);
    }

    return new EmptyResult();
}

// Make sure to add code blocks to your code group

2. 在后端编写代码调用webOpen方法打开文件之前给SaveFilePage属性赋值（设置好保存时由哪个地址接口负责接收处理控件上传的文件流）；

PageOfficeCtrl poCtrl = new PageOfficeCtrl(request);
poCtrl.setSaveFilePage("saveStream?filename=exampleobject.docx"); // 设置保存文件的接口地址
//webOpen的第一个参数支持能够输出下载文件的Url相对地址或者文件在服务器上的磁盘路径两种方式
//查看详细，请在本站搜索“PageOffice属性或方法中涉及到的URL路径或磁盘路径的说明”
poCtrl.webOpen("openStream?filename=exampleobject.docx", OpenModeType.docNormalEdit, "张佚名");//打开文件

PageOfficeNetCore.PageOfficeCtrl poCtrl = new PageOfficeNetCore.PageOfficeCtrl(Request);
poCtrl.SaveFilePage = "SaveStream?filename=exampleobject.docx";
poCtrl.WebOpen("OpenStream?filename=exampleobject.docx", PageOfficeNetCore.OpenModeType.docNormalEdit, "tom");

// Make sure to add code blocks to your code group

注意

对PageOfficeCtrl对象的所有属性赋值或函数调用都必须在WebOpen方法调用之前执行，否则会不生效。

3. 在SaveFilePage属性指向的地址接口saveStream中，创建FileSaver对象处理文件的保存工作。

@RequestMapping("saveStream")
public void saveStream(HttpServletRequest request, HttpServletResponse response) 
                      throws ClassNotFoundException, FileNotFoundException, SQLException {
    FileSaver fs = new FileSaver(request, response);

    String fileName = request.getParameter("filename");
    // Endpoint以华东1（杭州）为例，其它Region请按实际情况填写。
    String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
    // 阿里云账号AccessKey。
    String accessKeyId = "yourAccessKeyId";
    String accessKeySecret = "yourAccessKeySecret";
    // 填写Bucket名称，例如examplebucket。
    String bucketName = "examplebucket";
    // 填写Object完整路径，例如exampledir/exampleobject.docx。Object完整路径中不能包含Bucket名称。
    String objectName = "exampledir/" + fileName;

    // 创建OSSClient实例。
    OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);

    try {
        ossClient.putObject(bucketName, objectName, new ByteArrayInputStream(fs.getFileBytes()));
    } catch (OSSException oe) {
        System.out.println("Caught an OSSException, which means your request made it to OSS, "
                + "but was rejected with an error response for some reason.");
        System.out.println("Error Message:" + oe.getErrorMessage());
        System.out.println("Error Code:" + oe.getErrorCode());
        System.out.println("Request ID:" + oe.getRequestId());
        System.out.println("Host ID:" + oe.getHostId());
    } catch (ClientException ce) {
        System.out.println("Caught an ClientException, which means the client encountered "
                + "a serious internal problem while trying to communicate with OSS, "
                + "such as not being able to access the network.");
        System.out.println("Error Message:" + ce.getMessage());
    } finally {
        if (ossClient != null) {
            ossClient.shutdown();
        }
    }

    fs.close();
}

public async Task<ActionResult> SaveStream()
{
    String fileName = Request.Query["filename"];

    PageOfficeNetCore.FileSaver fs = new PageOfficeNetCore.FileSaver(Request, Response);
    await fs.LoadAsync();

    // yourEndpoint填写Bucket所在地域对应的Endpoint。以华东1（杭州）为例，Endpoint填写为https://oss-cn-hangzhou.aliyuncs.com。
    var endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
    // 从环境变量中获取访问凭证。运行本代码示例之前，请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
    var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
    var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
    // 填写Bucket名称，例如examplebucket。
    var bucketName = "examplebucket";
    // 填写Object完整路径，完整路径中不能包含Bucket名称，例如exampledir/exampleobject.docx。
    var objectName = "exampledir/" + fileName;

    // 创建OssClient实例。
    var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
    try
    {
        byte[] binaryData = fs.FileBytes;
        MemoryStream requestContent = new MemoryStream(binaryData);
        // 上传文件。
        client.PutObject(bucketName, objectName, requestContent);
        Console.WriteLine("Put object succeeded");
    }
    catch (Exception ex)
    {
        Console.WriteLine("Put object failed, {0}", ex.Message);
    }

    return fs.Close();
}

// Make sure to add code blocks to your code group

前端代码

本示例无前端关键代码。