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如何使用 Java 分块上传大文件？

发布于 2024-11-08 21:07:51 字数 49 浏览 0 评论 0原文

我需要使用 Java 分块上传一个大文件。

有没有示例代码可以参考？

原文

I need to upload a large file in chunks using Java.

Is there any sample code I can refer to?

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评论（5）

那一片橙海， 2024-11-15 21:07:51

*可以使用 plupload 来完成。
这是样本。
我的index.html如下：-

    <!DOCTYPE html>
    <html>
    <head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <title>Upload</title>
    <!-- production -->
    <script type="text/javascript" src="js/plupload.full.min.js"></script>
    <!-- debug 
    <script type="text/javascript" src="../js/moxie.js"></script>
    <script type="text/javascript" src="../js/plupload.dev.js"></script>
    -->
    </head>
    <body style="font: 13px Verdana; background: #eee; color: #333">
    <div id="filelist"></div>
    <br />
        <button id="pickfiles" >Select file</button> 
        <button id="uploadfiles" >Upload</button>
        <div id="container">
    </div>
    <br />
    <pre id="console"></pre>
    <script type="text/javascript">
    // Custom example logic
    var uploader = new plupload.Uploader({
        runtimes : 'html5',
        browse_button : 'pickfiles', // you can pass an id...
        container: document.getElementById('container'), // ... or DOM Element itself
        url : 'UploadAction',//upload.php
        chunk_size : '1mb',
        method:'POST',
        flash_swf_url : 'js/Moxie.swf',
        silverlight_xap_url : 'js/Moxie.xap',

        filters : {
            max_file_size : '100gb',
            mime_types: [
                {title : "Image files", extensions : "jpg,gif,png"},
                {title : "Zip files", extensions : "zip,txt,vmdk"}
            ]
        },
        init: {
            PostInit: function() {
                document.getElementById('filelist').innerHTML = '';
                document.getElementById('uploadfiles').onclick = function() {
                    uploader.start();
                    return false;
                };
            },
            FilesAdded: function(up, files) {
                plupload.each(files, function(file) {
                    document.getElementById('filelist').innerHTML += '<div id="' + file.id + '">' + file.name + ' (' + plupload.formatSize(file.size) + ') <b></b></div>';
                });
            },
            UploadProgress: function(up, file) {
                document.getElementById(file.id).getElementsByTagName('b')[0].innerHTML = '<span>' + file.percent + "%</span>";
            },
            Error: function(up, err) {
                document.getElementById('console').appendChild(document.createTextNode("\nError #" + err.code + ": " + err.message));
            }
        }
    });
    uploader.init();
    </script>
    </body>
    </html>
<!-- end snippet -->

我的java后端代码（Servlet）如下：-

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItemIterator;
import org.apache.commons.fileupload.FileItemStream;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.util.Streams;
public class UploadAction extends HttpServlet {
    private static final long serialVersionUID = 3447685998419256747L;
    private static final String RESP_SUCCESS = "{\"jsonrpc\" : \"2.0\", \"result\" : \"success\", \"id\" : \"id\"}";
    private static final String RESP_ERROR = "{\"jsonrpc\" : \"2.0\", \"error\" : {\"code\": 101, \"message\": \"Failed to open input stream.\"}, \"id\" : \"id\"}";
    public static final String JSON = "application/json";
    public static final int BUF_SIZE = 2 * 1024;
    public static final String FileDir = "/home/asjha/uploads/";

    private int chunk;
    private int chunks;
    private String name;
    private String user;
    private String time;
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String responseString = RESP_SUCCESS;
        boolean isMultipart = ServletFileUpload.isMultipartContent(req);

        if(isMultipart){
            ServletFileUpload upload = new ServletFileUpload();
            try {
                FileItemIterator iter = upload.getItemIterator(req);
                while (iter.hasNext()) {
                    FileItemStream item = iter.next();
                    InputStream input = item.openStream();
                    // Handle a form field.
                    if(item.isFormField()){
                        String fileName = item.getFieldName();
                        String value = Streams.asString(input);
                        if("name".equals(fileName)){
                            this.name = value;
                        }else if("chunks".equals(fileName)){
                            this.chunks = Integer.parseInt(value);
                        }else if("chunk".equals(fileName)){
                            this.chunk = Integer.parseInt(value);
                        }else if("user".equals(fileName)){
                            this.user = value;
                        }else if("time".equals(fileName)){
                            this.time = value;
                        }
                    }

                    // Handle a multi-part MIME encoded file.
                    else {
                        File dstFile = new File(FileDir);
                        if (!dstFile.exists()){
                            dstFile.mkdirs();
                        }

                        File dst = new File(dstFile.getPath()+ "/" + this.name);

                        saveUploadFile(input, dst);
                    }
                }
            }
            catch (Exception e) {
                responseString = RESP_ERROR;
                e.printStackTrace();
            }
        }

        // Not a multi-part MIME request.
        else {
            responseString = RESP_ERROR;
        }

        if(this.chunk == this.chunks - 1){
            System.out.println("name"+this.name);
        }
        resp.setContentType(JSON);
        byte[] responseBytes = responseString.getBytes();
        resp.setContentLength(responseBytes.length);
        ServletOutputStream output = resp.getOutputStream();
        output.write(responseBytes);
        output.flush();
    }
    private void saveUploadFile(InputStream input, File dst) throws IOException {
        OutputStream out = null;
        try {
            if (dst.exists()) {
                out = new BufferedOutputStream(new FileOutputStream(dst, true),
                        BUF_SIZE);
            } else {
                out = new BufferedOutputStream(new FileOutputStream(dst),
                        BUF_SIZE);
            }
            byte[] buffer = new byte[BUF_SIZE];
            int len = 0;
            while ((len = input.read(buffer)) > 0) {
                out.write(buffer, 0, len);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (null != input) {
                try {
                    input.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != out) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

请参阅plupload了解详细信息，在github上您可以看到jakobadam和rocky的示例项目。

如果需要上传多个文件，请告诉我。使用 plupload 我们可以上传任意数量、任意大小的文件。此示例适用于非常大的单个文件上传。
不要忘记包含 plupload.full.min.js。希望这有帮助*强调文字**

*It can be done using plupload.
Here is sample.
My index.html is as under:-

    <!DOCTYPE html>
    <html>
    <head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <title>Upload</title>
    <!-- production -->
    <script type="text/javascript" src="js/plupload.full.min.js"></script>
    <!-- debug 
    <script type="text/javascript" src="../js/moxie.js"></script>
    <script type="text/javascript" src="../js/plupload.dev.js"></script>
    -->
    </head>
    <body style="font: 13px Verdana; background: #eee; color: #333">
    <div id="filelist"></div>
    <br />
        <button id="pickfiles" >Select file</button> 
        <button id="uploadfiles" >Upload</button>
        <div id="container">
    </div>
    <br />
    <pre id="console"></pre>
    <script type="text/javascript">
    // Custom example logic
    var uploader = new plupload.Uploader({
        runtimes : 'html5',
        browse_button : 'pickfiles', // you can pass an id...
        container: document.getElementById('container'), // ... or DOM Element itself
        url : 'UploadAction',//upload.php
        chunk_size : '1mb',
        method:'POST',
        flash_swf_url : 'js/Moxie.swf',
        silverlight_xap_url : 'js/Moxie.xap',

        filters : {
            max_file_size : '100gb',
            mime_types: [
                {title : "Image files", extensions : "jpg,gif,png"},
                {title : "Zip files", extensions : "zip,txt,vmdk"}
            ]
        },
        init: {
            PostInit: function() {
                document.getElementById('filelist').innerHTML = '';
                document.getElementById('uploadfiles').onclick = function() {
                    uploader.start();
                    return false;
                };
            },
            FilesAdded: function(up, files) {
                plupload.each(files, function(file) {
                    document.getElementById('filelist').innerHTML += '<div id="' + file.id + '">' + file.name + ' (' + plupload.formatSize(file.size) + ') <b></b></div>';
                });
            },
            UploadProgress: function(up, file) {
                document.getElementById(file.id).getElementsByTagName('b')[0].innerHTML = '<span>' + file.percent + "%</span>";
            },
            Error: function(up, err) {
                document.getElementById('console').appendChild(document.createTextNode("\nError #" + err.code + ": " + err.message));
            }
        }
    });
    uploader.init();
    </script>
    </body>
    </html>
<!-- end snippet -->

My java backend code(Servlet) is as under:-

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItemIterator;
import org.apache.commons.fileupload.FileItemStream;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.util.Streams;
public class UploadAction extends HttpServlet {
    private static final long serialVersionUID = 3447685998419256747L;
    private static final String RESP_SUCCESS = "{\"jsonrpc\" : \"2.0\", \"result\" : \"success\", \"id\" : \"id\"}";
    private static final String RESP_ERROR = "{\"jsonrpc\" : \"2.0\", \"error\" : {\"code\": 101, \"message\": \"Failed to open input stream.\"}, \"id\" : \"id\"}";
    public static final String JSON = "application/json";
    public static final int BUF_SIZE = 2 * 1024;
    public static final String FileDir = "/home/asjha/uploads/";

    private int chunk;
    private int chunks;
    private String name;
    private String user;
    private String time;
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String responseString = RESP_SUCCESS;
        boolean isMultipart = ServletFileUpload.isMultipartContent(req);

        if(isMultipart){
            ServletFileUpload upload = new ServletFileUpload();
            try {
                FileItemIterator iter = upload.getItemIterator(req);
                while (iter.hasNext()) {
                    FileItemStream item = iter.next();
                    InputStream input = item.openStream();
                    // Handle a form field.
                    if(item.isFormField()){
                        String fileName = item.getFieldName();
                        String value = Streams.asString(input);
                        if("name".equals(fileName)){
                            this.name = value;
                        }else if("chunks".equals(fileName)){
                            this.chunks = Integer.parseInt(value);
                        }else if("chunk".equals(fileName)){
                            this.chunk = Integer.parseInt(value);
                        }else if("user".equals(fileName)){
                            this.user = value;
                        }else if("time".equals(fileName)){
                            this.time = value;
                        }
                    }

                    // Handle a multi-part MIME encoded file.
                    else {
                        File dstFile = new File(FileDir);
                        if (!dstFile.exists()){
                            dstFile.mkdirs();
                        }

                        File dst = new File(dstFile.getPath()+ "/" + this.name);

                        saveUploadFile(input, dst);
                    }
                }
            }
            catch (Exception e) {
                responseString = RESP_ERROR;
                e.printStackTrace();
            }
        }

        // Not a multi-part MIME request.
        else {
            responseString = RESP_ERROR;
        }

        if(this.chunk == this.chunks - 1){
            System.out.println("name"+this.name);
        }
        resp.setContentType(JSON);
        byte[] responseBytes = responseString.getBytes();
        resp.setContentLength(responseBytes.length);
        ServletOutputStream output = resp.getOutputStream();
        output.write(responseBytes);
        output.flush();
    }
    private void saveUploadFile(InputStream input, File dst) throws IOException {
        OutputStream out = null;
        try {
            if (dst.exists()) {
                out = new BufferedOutputStream(new FileOutputStream(dst, true),
                        BUF_SIZE);
            } else {
                out = new BufferedOutputStream(new FileOutputStream(dst),
                        BUF_SIZE);
            }
            byte[] buffer = new byte[BUF_SIZE];
            int len = 0;
            while ((len = input.read(buffer)) > 0) {
                out.write(buffer, 0, len);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (null != input) {
                try {
                    input.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != out) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

Please refer to plupload for details and on github you can see sample projects by jakobadam and rocky.

Please let me know if multiple file upload is required. Using plupload we can upload any number of files of any sizes. This sample is for single file upload of very large size.
dont forget to include plupload.full.min.js. Hope this helps*emphasized text**

回复 原文
我不是你的备胎 2024-11-15 21:07:51

以下是使用块上传文件的本机 Java 代码示例：

final String       LF = "\r\n"; // Line separator required by multipart/form-data. Can be static class constant
final String boundary = Long.toHexString(System.currentTimeMillis()); // Just generate some unique random value.

HttpURLConnection connection = (HttpURLConnection) new URL("http://some.com/upload").openConnection();
try {
    connection.setDoOutput(true);
    connection.setChunkedStreamingMode(4096);
    connection.setRequestMethod("POST");
    connection.addRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
    connection.addRequestProperty("Accept", "application/json");
    connection.addRequestProperty("Authorization", myToken);
    try (OutputStream os = connection.getOutputStream();
            Writer writer = new OutputStreamWriter(os, StandardCharsets.UTF_8)) {
        writer.append("--").append(boundary).append(LF);
        writer.append("Content-Disposition: form-data; name=\"dataFile\"; filename=\"file.zip\"").append(LF);
        writer.append("Content-Type: application/zip").append(LF);
        writer.append(LF);
        writer.flush();

        // Write body
        writeBinaryBody(os);
        writer.append(LF).append("--").append(boundary).append("--").append(LF);
        writer.flush();
        os.flush();
    }
    if (200 != connection.getResponseCode()) {
        try (Reader reader = new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8)) {
            // Handle error here
        }
    }
} finally {
    connection.disconnect();
}

此示例中的代码基于此答案从java上传http文件。区别在于对 connection.setChunkedStreamingMode(4096); 的调用定义了应使用分块流。

Here is an example of native Java code that uploads a file using chunks:

final String       LF = "\r\n"; // Line separator required by multipart/form-data. Can be static class constant
final String boundary = Long.toHexString(System.currentTimeMillis()); // Just generate some unique random value.

HttpURLConnection connection = (HttpURLConnection) new URL("http://some.com/upload").openConnection();
try {
    connection.setDoOutput(true);
    connection.setChunkedStreamingMode(4096);
    connection.setRequestMethod("POST");
    connection.addRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
    connection.addRequestProperty("Accept", "application/json");
    connection.addRequestProperty("Authorization", myToken);
    try (OutputStream os = connection.getOutputStream();
            Writer writer = new OutputStreamWriter(os, StandardCharsets.UTF_8)) {
        writer.append("--").append(boundary).append(LF);
        writer.append("Content-Disposition: form-data; name=\"dataFile\"; filename=\"file.zip\"").append(LF);
        writer.append("Content-Type: application/zip").append(LF);
        writer.append(LF);
        writer.flush();

        // Write body
        writeBinaryBody(os);
        writer.append(LF).append("--").append(boundary).append("--").append(LF);
        writer.flush();
        os.flush();
    }
    if (200 != connection.getResponseCode()) {
        try (Reader reader = new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8)) {
            // Handle error here
        }
    }
} finally {
    connection.disconnect();
}

The code in this example is based on this answer about http file upload from java. The difference is the call to connection.setChunkedStreamingMode(4096); that defines that chunked streaming should be used.

回复 原文
究竟谁懂我的在乎 2024-11-15 21:07:51

尝试 Apache Commons 上传。它支持流媒体，可能适合您。

Try Apache Commons upload. It supports streaming, may be suitable for you.

回复 原文
绝影如岚 2024-11-15 21:07:51

您可以简单地自己分解文件，使用 Socket API，并重新组装文件。

You can simply break the file up yourself, send it using the Socket API, and re-assemble the file.

回复 原文
我爱人 2024-11-15 21:07:51

使用随机访问文件。我相信这已经在 SO 上进行了介绍。

具有 rewind()/reset() 功能的 java 文件输入

只需寻找起点，从那里写入您想要的任意字节，并记住您停止写入的点。

Use a RandomAccessFile. This has already been covered on SO I believe.

java file input with rewind()/reset() capability

Basically you'd just seek to the starting point, write however many bytes you want to from there, and remember the point you stopped writing from.

回复 原文
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