FLASK与JAVA的文件互传（单文件互传亲测）

配置：JAVA需要的jar包httpclient4-5-14

python需要的配置：

# # 安装 Windows 兼容版本
# pip install python-magic-bin
#pip install flask

JAVA端的代码：

HttpClient4514FileUpload.java

package HttpFlask;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
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;
import java.nio.charset.StandardCharsets;public class HttpClient4514FileUpload {/*** 基础文件上传方法* @param url 上传地址* @param file 要上传的文件* @return 服务器响应内容*/public static String uploadFile(String url, File file) throws IOException {CloseableHttpClient httpClient = HttpClients.createDefault();try {HttpPost httpPost = new HttpPost(url);// 使用 MultipartEntityBuilder 构建多部分表单数据MultipartEntityBuilder builder = MultipartEntityBuilder.create();// 添加文件部分FileBody fileBody = new FileBody(file, ContentType.DEFAULT_BINARY, file.getName());builder.addPart("file", fileBody); // "file" 是表单字段名// 添加文本参数（可选）StringBody commentBody = new StringBody("文件上传示例",ContentType.TEXT_PLAIN.withCharset(StandardCharsets.UTF_8));builder.addPart("comment", commentBody);// 构建实体HttpEntity multipartEntity = builder.build();httpPost.setEntity(multipartEntity);// 执行请求CloseableHttpResponse response = httpClient.execute(httpPost);try {// 获取响应实体HttpEntity responseEntity = response.getEntity();String responseString = EntityUtils.toString(responseEntity);// 确保响应实体被完全消费EntityUtils.consume(responseEntity);System.out.println("响应状态: " + response.getStatusLine().getStatusCode());return responseString;} finally {response.close();}} finally {httpClient.close();}}
}

JAVA测试：HTTPFlask

public class FileHttpFlask {public static void main(String[] args) {try {// 示例1: 基础文件上传String urlSingle = "http://127.0.0.1:5000/api/upload";File file = new File("E:\\testWorkPlace\\testrun\\src\\HttpFlask\\upload.txt");String result = HttpClient4514FileUpload.uploadFile(urlSingle, file);System.out.println("基础上传结果: " + result);} catch (IOException e) {e.printStackTrace();}}
}

对应flask代码：

from flask import Flask, request, jsonify, render_template_string, send_file
import os
import uuid
from werkzeug.utils import secure_filename
from datetime import datetime
import magic  # 用于更准确的文件类型检测
from datetime import datetime
import time
# # 安装 Windows 兼容版本
# pip install python-magic-bin
app = Flask(__name__)# 配置文件上传
app.config.update(UPLOAD_FOLDER='uploads',MAX_CONTENT_LENGTH=16 * 1024 * 1024,  # 16MBALLOWED_EXTENSIONS={'txt', 'pdf', 'png', 'jpg', 'jpeg', 'gif', 'doc', 'docx', 'zip'},SECRET_KEY='your-secret-key-here'
)# 用于存储上传统计信息
upload_stats = {'total_files': 0,'total_size': 0,'last_upload': None
}
# 创建上传目录
os.makedirs(app.config['UPLOAD_FOLDER'], exist_ok=True)class FileUploader:"""文件上传工具类"""@staticmethoddef allowed_file(filename):"""检查文件扩展名"""return '.' in filename and \filename.rsplit('.', 1)[1].lower() in app.config['ALLOWED_EXTENSIONS']@staticmethoddef generate_unique_filename(original_filename):"""生成唯一文件名"""timestamp = datetime.now().strftime("%Y%m%d_%H%M%S_%f")unique_id = str(uuid.uuid4())[:8]safe_name = secure_filename(original_filename)return f"{timestamp}_{unique_id}_{safe_name}"@staticmethoddef get_file_info(file_path):"""获取文件详细信息"""stat = os.stat(file_path)file_type = "unknown"try:# 使用python-magic检测文件类型import magicfile_type = magic.from_file(file_path, mime=True)except:# 备用方案：使用文件扩展名ext = os.path.splitext(file_path)[1].lower()file_type = f"application/{ext[1:]}" if ext else "unknown"return {'size': stat.st_size,'created_time': datetime.fromtimestamp(stat.st_ctime).isoformat(),'modified_time': datetime.fromtimestamp(stat.st_mtime).isoformat(),'type': file_type}@app.route('/api/upload', methods=['POST'])
def api_upload_file():"""API: 单文件上传"""try:if 'file' not in request.files:return jsonify({'success': False, 'error': '没有文件部分'}), 400file = request.files['file']description = request.form.get('description', '')tags = request.form.get('tags', '')if file.filename == '':return jsonify({'success': False, 'error': '没有选择文件'}), 400if not FileUploader.allowed_file(file.filename):return jsonify({'success': False, 'error': '不允许的文件类型'}), 400# 生成唯一文件名unique_filename = FileUploader.generate_unique_filename(file.filename)file_path = os.path.join(app.config['UPLOAD_FOLDER'], unique_filename)# 保存文件file.save(file_path)# 获取文件信息file_info = FileUploader.get_file_info(file_path)response_data = {'success': True,'message': '文件上传成功','file': {'id': unique_filename,'original_name': file.filename,'saved_name': unique_filename,'description': description,'tags': [tag.strip() for tag in tags.split(',')] if tags else [],'upload_time': datetime.now().isoformat(),**file_info}}return jsonify(response_data), 200except Exception as e:return jsonify({'success': False, 'error': str(e)}), 500

运行结果：

上传成功！