當(dāng)前位置:首頁(yè) > IT技術(shù) > Web編程 > 正文

HttpClient使用管道流提交Multipart請(qǐng)求
2021-09-24 14:43:37

HttpClient 是JDK11提供的一個(gè)全新HTTP客戶端Api,超級(jí)好用。

Multipart 請(qǐng)求

HttpClient 并沒(méi)有提供 Multipart 請(qǐng)求體的構(gòu)建Api。但是可以使用apache的開(kāi)源httpmime庫(kù)來(lái)進(jìn)行構(gòu)建。

<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
    <version>4.5.13</version>
</dependency>

構(gòu)建一個(gè) MultipartBody

// 構(gòu)建Multipart請(qǐng)求
HttpEntity httpEntity = MultipartEntityBuilder.create()
		// 表單數(shù)據(jù)
		.addPart("name", new StringBody(UriUtils.encode("SpringBoot中文社區(qū)", StandardCharsets.UTF_8), ContentType.APPLICATION_FORM_URLENCODED))
		// JSON數(shù)據(jù)
		.addPart("info", new StringBody("{"site": "https://springboot.io", "now": 2021}", ContentType.APPLICATION_JSON))
		// 文件數(shù)據(jù)
		.addBinaryBody("file", file, ContentType.APPLICATION_OCTET_STREAM, "eclipse-jee-2019-12-R-win32-x86_64.zip")
		.build();

ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream((int) httpEntity.getContentLength());

// 把body寫入到內(nèi)存
httpEntity.writeTo(byteArrayOutputStream);

Multipart 請(qǐng)求可以一次性post多個(gè)子body,通常用來(lái)上傳本地磁盤上的文件。所以這種請(qǐng)求體可能會(huì)異常龐大。甚至內(nèi)存不能完整的存入整個(gè)請(qǐng)求體。那么這個(gè)時(shí)候有2種辦法可以解決。

  1. 先把構(gòu)建好的Body數(shù)據(jù)寫入到磁盤,再通過(guò)IO磁盤數(shù)據(jù),提交給服務(wù)器
  2. 使用管道流,在讀取磁盤數(shù)據(jù)進(jìn)行body構(gòu)建的時(shí)候,直接通過(guò)管道提交到遠(yuǎn)程服務(wù)器

管道流

管道流,顧名思義,可以往一邊寫,從另一邊讀。

// 創(chuàng)建讀取流
PipedInputStream pipedInputStream = new PipedInputStream();
// 創(chuàng)建寫入流
PipedOutputStream pipedOutputStream = new PipedOutputStream();
// 連接寫入和讀取流
pipedInputStream.connect(pipedOutputStream);

通過(guò)往pipedOutputStream寫入數(shù)據(jù),就可以在pipedInputStream 讀取。

不能使用單線程既讀又寫,因?yàn)樽x寫都是阻塞方法。任何一方阻塞住了了,另一方就會(huì)一直處于等待狀態(tài),導(dǎo)致死鎖

完整Demo

客戶端

package io.springcloud.test;

import java.io.IOException;
import java.io.InputStream;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpRequest.BodyPublishers;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;

import org.apache.http.HttpEntity;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.StringBody;
import org.springframework.web.util.UriUtils;

public class MainTest {


	public static void main(String[] args) throws Exception {
		
		// 管道流
		PipedInputStream pipedInputStream = new PipedInputStream();
		PipedOutputStream pipedOutputStream = new PipedOutputStream();
		pipedInputStream.connect(pipedOutputStream);
		
		// 本地文件
		InputStream file =  Files.newInputStream(Paths.get("D:\eclipse-jee-2019-12-R-win32-x86_64.zip"));
		
		// 構(gòu)建Multipart請(qǐng)求
		HttpEntity httpEntity = MultipartEntityBuilder.create()
				// 表單數(shù)據(jù)
				.addPart("name", new StringBody(UriUtils.encode("SpringBoot中文社區(qū)", StandardCharsets.UTF_8), ContentType.APPLICATION_FORM_URLENCODED))
				// JSON數(shù)據(jù)
				.addPart("info", new StringBody("{"site": "https://springboot.io", "now": 2021}", ContentType.APPLICATION_JSON))
				// 文件數(shù)據(jù)
				.addBinaryBody("file", file, ContentType.APPLICATION_OCTET_STREAM, "eclipse-jee-2019-12-R-win32-x86_64.zip")
				.build();
		
		// 異步寫入數(shù)據(jù)到管道流
		new Thread(() -> {
			try (file; pipedOutputStream){
				httpEntity.writeTo(pipedOutputStream);
			} catch (IOException e) {
				e.printStackTrace();
			}
		}).start();
		
		HttpClient httpClient = HttpClient.newHttpClient();
		
		try (pipedInputStream){
			// 創(chuàng)建請(qǐng)求和請(qǐng)求體
			HttpRequest request = HttpRequest
						.newBuilder(new URI("http://localhost/upload"))
						// 設(shè)置ContentType
						.header("Content-Type", httpEntity.getContentType().getValue())
						.header("Accept", "text/plain")   
						// 從管道流讀取數(shù)據(jù),提交給服務(wù)器
						.POST(BodyPublishers.ofInputStream(() -> pipedInputStream))
						.build();
			
			// 執(zhí)行請(qǐng)求,獲取響應(yīng)
			HttpResponse<String> responseBody = httpClient.send(request, BodyHandlers.ofString(StandardCharsets.UTF_8));
			
			System.out.println(responseBody.body());
		}
	}
}

服務(wù)端

package io.springcloud.web.controller;

import java.nio.charset.StandardCharsets;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestPart;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.util.UriUtils;

import com.google.gson.JsonObject;


@RestController
@RequestMapping("/upload")
public class UploadController {
	
	private static final Logger LOGGER = LoggerFactory.getLogger(UploadController.class);
	
	@PostMapping
	public Object upload (@RequestPart("file") MultipartFile file,
						@RequestPart("info") JsonObject info,
						@RequestPart("name") String name) {
		
		LOGGER.info("file: name={}, size={}", file.getOriginalFilename(), file.getSize());
		LOGGER.info("info: {}", info.toString());
		LOGGER.info("name: {}", UriUtils.decode(name, StandardCharsets.UTF_8));
		
		return ResponseEntity.ok("success");
	}
}

啟動(dòng)服務(wù)端后,執(zhí)行客戶端請(qǐng)求,服務(wù)端日志輸出

2021-09-24 13:38:15.067  INFO 2660 --- [  XNIO-1 task-1] i.s.web.controller.UploadController      : file: name=eclipse-jee-2019-12-R-win32-x86_64.zip, size=369653147
2021-09-24 13:38:15.067  INFO 2660 --- [  XNIO-1 task-1] i.s.web.controller.UploadController      : info: {"site":"https://springboot.io","now":2021}
2021-09-24 13:38:15.067  INFO 2660 --- [  XNIO-1 task-1] i.s.web.controller.UploadController      : name: SpringBoot中文社區(qū)

首發(fā):https://springboot.io/t/topic/4185

本文摘自 :https://www.cnblogs.com/

開(kāi)通會(huì)員,享受整站包年服務(wù)立即開(kāi)通 >