使用HttpClient發送文件流到服務器端

時間 2019-11-18

原文原文鏈接

適用場景：
網絡絕對路徑的URL文件或圖片，不存儲到本地，轉換成stream,直接使用HTTPClient傳送到SpringBoot的服務端，將文件存儲下來，並返回一個文件地址。目前分層架構的系統愈來愈多這種需求，因此記錄下來以備不時之需。

一、調用端
首先引入httpclient所需包

<dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.4</version>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpmime</artifactId>
        <version>4.4</version>
    </dependency>

調用代碼：html

package test.http;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
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.*;
import java.net.URL;
import java.nio.charset.Charset;

/**
 * 文件傳送
 * 發送文件流到服務器端
 * 服務器端使用SpringBoot的MultipartFile接收
 *
 * 適用場景：
 * 絕對路徑的URL文件，不存儲到本地，轉換成stream,直接使用HTTPClient傳送到SpringBoot
 *
 */
public class TestUpload {

    public static void main(String[] args) {
        //文件URL，此處取豆瓣上的一個圖片
        String fileUrl ="https://img1.doubanio.com/view/photo/l/public/p2537149328.webp";
        try {
            //提取到文件名
            String fileName = fileUrl.substring(fileUrl.lastIndexOf("/")+1);
            //轉換成文件流
            InputStream is = new URL(fileUrl).openStream();

            //接收文件的服務器地址
            String uploadURL = "http://localhost:8003/fileupload";

            //建立HttpClient
            CloseableHttpClient httpClient = HttpClients.createDefault();
            HttpPost httpPost = new HttpPost(uploadURL);
            MultipartEntityBuilder builder = MultipartEntityBuilder.create();
            /*綁定文件參數，傳入文件流和contenttype，此處也能夠繼續添加其餘formdata參數*/
            builder.addBinaryBody("file",is, ContentType.MULTIPART_FORM_DATA,fileName);
            HttpEntity entity = builder.build();
            httpPost.setEntity(entity);

            //執行提交
            HttpResponse response = httpClient.execute(httpPost);
            HttpEntity responseEntity = response.getEntity();
            if(responseEntity != null){
                //將響應的內容轉換成字符串
                String result = EntityUtils.toString(responseEntity, Charset.forName("UTF-8"));

                //此處根據服務器返回的參數轉換，這裏返回的是JSON格式
                JSONObject output = JSON.parseObject(result);
                JSONArray body = output.getJSONArray("body");
                String resUrl = body.get(0)+"";

                System.out.println(resUrl);
            }
　　　　　　　　if(is != null){
                is.close();
　　　　　　　　}
　　　　　　　　
        }catch (Exception ex){
            ex.printStackTrace();
        }

    }
}

二、服務端java

服務端直接使用MultipartFile接收便可web

/**
     * 上傳文件
     * 
     * @throws BusinessException
     */
    @PostMapping("")
    public String upload(@RequestParam(defaultValue = "", required = false) String prefix,
            @RequestParam("file") MultipartFile... files) throws BusinessException {
        ResultView<List<String>> resultView = new ResultView<>();
        List<String> list = new ArrayList<>();
        for (MultipartFile file : files) {
            if (file.isEmpty()) {
                log.warn("have empty upload file,you need check is right?");
                continue;
            }
            String filepath = storageService.store(file, prefix);
            list.add(fileServerAddress + filepath.replaceAll("\\\\", "/"));
        }

        resultView.setBody(list);
        log.info(JSONObject.toJSONString(resultView));
        return JSONObject.toJSONString(resultView);
    }