在Java中，可以使用Apache HttpClient庫來實現form-data形式的文件上傳。下面是一個簡單的示例代碼：

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

import java.io.File;
import java.io.IOException;

public class FileUploader {
    public static void main(String[] args) throws IOException {
        // 創建HttpClient對象
        CloseableHttpClient httpClient = HttpClients.createDefault();

        // 創建HttpPost對象，并設置URL
        HttpPost httpPost = new HttpPost("http://example.com/upload");

        // 創建MultipartEntityBuilder對象，并設置文件和其他參數
        MultipartEntityBuilder builder = MultipartEntityBuilder.create();
        builder.addBinaryBody("file", new File("path/to/file"), ContentType.MULTIPART_FORM_DATA, "filename");
        builder.addTextBody("param1", "value1");
        builder.addTextBody("param2", "value2");

        // 將MultipartEntityBuilder構建的實體對象設置到HttpPost對象中
        HttpEntity entity = builder.build();
        httpPost.setEntity(entity);

        // 執行HttpPost請求，獲取響應
        HttpResponse response = httpClient.execute(httpPost);

        // 解析響應
        HttpEntity responseEntity = response.getEntity();
        String responseBody = EntityUtils.toString(responseEntity);
        System.out.println(responseBody);

        // 關閉HttpClient
        httpClient.close();
    }
}

上面的示例代碼中，使用MultipartEntityBuilder創建一個multipart/form-data實體，通過addBinaryBody添加文件參數，通過addTextBody添加其他參數。然后將該實體設置到HttpPost對象中，最后使用HttpClient執行請求并獲取響應。請根據實際情況修改URL、文件路徑和參數名。