HttpClient5 分片上传完整示例

HttpClient5 是 Apache HttpClient 的最新版本，支持 HTTP/1.1 和 HTTP/2 协议，提供了更加简洁易用的 API。以下是 HttpClient5 分片上传的完整示例：

import org.apache.hc.client5.http.classic.methods.HttpPost;
import org.apache.hc.client5.http.entity.mime.FileBody;
import org.apache.hc.client5.http.entity.mime.MultipartEntityBuilder;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.HttpEntity;
import org.apache.hc.core5.http.HttpResponse;
import org.apache.hc.core5.http.HttpStatus;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class HttpClient5Example {

    private static final String UPLOAD_URL = "http://example.com/upload";

    public static void main(String[] args) throws IOException {
        Path path = Paths.get("path/to/file");
        int chunkSize = 1024 * 1024; // 1MB
        long fileSize = Files.size(path);
        int chunks = (int) Math.ceil((double) fileSize / chunkSize);

        // Create HTTP client
        try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
            // Create HTTP request
            HttpPost httpPost = new HttpPost(UPLOAD_URL);

            // Create multipart entity builder
            MultipartEntityBuilder entityBuilder = MultipartEntityBuilder.create();

            // Add file chunks to multipart entity
            for (int i = 0; i < chunks; i++) {
                long offset = i * chunkSize;
                long length = Math.min(chunkSize, fileSize - offset);
                Path chunkPath = Paths.get(path + ".part" + i);
                Files.copy(path, chunkPath);
                File chunkFile = chunkPath.toFile();
                FileBody fileBody = new FileBody(chunkFile);
                entityBuilder.addPart("file", fileBody);
            }

            // Build multipart entity
            HttpEntity entity = entityBuilder.build();
            httpPost.setEntity(entity);

            // Execute HTTP request
            HttpResponse response = httpClient.execute(httpPost);

            // Check HTTP status code
            int statusCode = response.getCode();
            if (statusCode == HttpStatus.SC_OK) {
                System.out.println("File uploaded successfully");
            } else {
                System.err.println("Failed to upload file");
            }
        }
    }
}

在这个示例中，我们使用了 Apache HttpClient5 的 MultipartEntityBuilder 来构建 multipart 请求实体。我们把文件切成了多个 chunk，并且添加到 multipart 实体中。在上传完成后，我们检查了 HTTP 状态码，以确定上传是否成功。