编排下载文件 | API管理系统|开放平台管理系统|API集成平台

# 版本要求

FizzGate集成平台v3.1.0或以上版本 (安装教程 (opens new window))

FizzGate集成平台从1.0开始已支持文件下载请求的转发，从v3.1.0开始在服务编排功能对下载文件进行了支持，以便进行更复杂的接口编排。

# 环境准备

创建一个服务来模拟已有的接口，准备两个文件attendance.xlsx和image1.jpg放在模拟服务的tmp目录下，代码：

FileDownloadController.java:

package we.controller;

import java.io.File;
import java.io.FileInputStream;
import java.nio.charset.Charset;

import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.core.io.buffer.DefaultDataBufferFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ZeroCopyHttpOutputMessage;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.server.ServerWebExchange;

import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

@RestController
public class FileDownloadController {

	@GetMapping(value = "/download/excel")
	public Mono<Void> downloadExcel(ServerWebExchange exchange, ServerHttpResponse response) {
		File file = new File("tmp/attendance.xlsx");
		// 这里为了模拟流 而去读取本地文件
		FileInputStream in = null;
		try {
			in = new FileInputStream(file);
			Flux<DataBuffer> dataBufferFlux = DataBufferUtils.readByteChannel(in::getChannel,
					new DefaultDataBufferFactory(), 4096);
			ZeroCopyHttpOutputMessage zeroCopyHttpOutputMessage = (ZeroCopyHttpOutputMessage) response;
			HttpHeaders headers = zeroCopyHttpOutputMessage.getHeaders();
			headers.set(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=attendance.xlsx");
			MediaType application = new MediaType("application", "vnd.ms-excel", Charset.forName("UTF-8"));
			headers.setContentType(application);
			return zeroCopyHttpOutputMessage.writeWith(dataBufferFlux);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return Mono.empty();
	}

	@GetMapping(value = "/download/image")
	public Mono<Void> downloadImage(ServerWebExchange exchange, ServerHttpResponse response) {
		File file = new File("tmp/image1.jpg");
		// 这里为了模拟流 而去读取本地文件
		FileInputStream in = null;
		try {
			in = new FileInputStream(file);
			Flux<DataBuffer> dataBufferFlux = DataBufferUtils.readByteChannel(in::getChannel,
					new DefaultDataBufferFactory(), 4096);
			ZeroCopyHttpOutputMessage zeroCopyHttpOutputMessage = (ZeroCopyHttpOutputMessage) response;
			HttpHeaders headers = zeroCopyHttpOutputMessage.getHeaders();
			headers.set(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=image1.jpg");
			MediaType application = new MediaType("application", "octet-stream", Charset.forName("UTF-8"));
			headers.setContentType(application);
			return zeroCopyHttpOutputMessage.writeWith(dataBufferFlux);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return Mono.empty();
	}

}

下载excel文件接口URL: http://127.0.0.1:8080/download/excel
下载图片接口URL: http://127.0.0.1:8080/download/image

服务编排下载excel和下载图片的配置是一样的，下面以下载excel为例子进行配置。