java分片上传代码实现

好的，关于Java分片上传的代码实现，我可以为您提供一份示例代码，您可以根据需要进行修改和调整：

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Random;

public class FileUploadTest {
    public static void main(String[] args) throws IOException {
        String urlStr = "http://localhost:8080/file/upload";
        File file = new File("D:\\test.mp4");
        String boundary = getBoundary(); //分割线

        HttpURLConnection conn = (HttpURLConnection)new URL(urlStr).openConnection();
        conn.setRequestMethod("POST");
        conn.setDoOutput(true);
        conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);

        OutputStream out = conn.getOutputStream();
        FileInputStream in = new FileInputStream(file);

        byte[] bytes = new byte[4096];
        int len;
        int fileSize = (int) file.length(); //文件大小
        int uploadedSize = 0; //已上传的文件大小

        //上传起始分片
        out.write(getStartBoundary(boundary, file.getName()).getBytes()); //boundary 和文件名
        while ((len = in.read(bytes)) != -1) {
            out.write(bytes, 0, len);
            uploadedSize += len;
            if (uploadedSize >= fileSize / 5) { //上传完 1/5 的文件大小就停止
                break;
            }
        }
        out.write("\r\n".getBytes()); //每个分片后面需要加上“\r\n”

        //上传中间分片
        while ((len = in.read(bytes)) != -1) {
            out.write(getMiddleBoundary(boundary).getBytes()); //boundary
            out.write(bytes, 0, len);
            uploadedSize += len;
            if (uploadedSize >= fileSize / 2) { //上传完 1/2 的文件大小就停止
                break;
            }
        }
        out.write("\r\n".getBytes());

        //上传结束分片
        out.write(getEndBoundary(boundary).getBytes()); //boundary
        in.close();
        out.close();

        //获取响应结果
        if (conn.getResponseCode() == 200) {
            System.out.println("文件上传成功！");
        } else {
            System.out.println("文件上传失败！");
        }

        conn.disconnect();
    }

    //生成分割线
    private static String getBoundary() {
        return "---------------------------" + new Random().nextLong();
    }

    //生成开始分片
    private static String getStartBoundary(String boundary, String fileName) {
        return "--" + boundary + "\r\n" +
                "Content-Disposition: form-data; name=\"file\"; filename=\"" + fileName + "\"\r\n" +
                "Content-Type: application/octet-stream\r\n\r\n";
    }

    //生成中间分片
    private static String getMiddleBoundary(String boundary) {
        return "\r\n--" + boundary + "\r\n" +
                "Content-Type: application/octet-stream\r\n\r\n";
    }

    //生成结束分片
    private static String getEndBoundary(String boundary) {
        return "\r\n--" + boundary + "--\r\n";
    }
}

这是一个比较简单的示例代码，可以实现Java分片上传的功能，您可以根据自己的需求进行修改和优化。