020 文件(图片)上传功能---涉及switchhost和Nginx的使用

文件的上传并不只是在品牌管理中有需求，以后的其它服务也可能需要，因此我们创建一个独立的微服务，专门处理各种上传。

1.搭建模块

(1)创建模块

(2)依赖

我们需要EurekaClient和web依赖：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>leyou</artifactId>
        <groupId>lucky.leyou.parent</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <groupId>lucky.leyou.upload</groupId>
    <artifactId>leyou-upload</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
    </dependencies>


</project>

(3)编写配置

server:
  port: 8082
spring:
  application:
    name: upload-service
  servlet:
    multipart:
      max-file-size: 5MB # 限制文件上传的大小
# Eureka
eureka:
  client:
    service-url:
      defaultZone: http://localhost:10086/eureka
  instance:
    lease-renewal-interval-in-seconds: 5 # 每隔5秒发送一次心跳
    lease-expiration-duration-in-seconds: 10 # 10秒不发送就过期

(4)引导类

package lucky.leyou;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class LeyouUploadApplication {

    public static void main(String[] args) {
        SpringApplication.run(LeyouUploadApplication.class, args);
    }
}

(5)模块初步结构图

2.编写上传功能

(1)Controller

package lucky.leyou.upload.controller;

import lucky.leyou.upload.service.IUploadService;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

@Controller
@RequestMapping(path = "/upload")
public class UploadController {

    @Autowired
    IUploadService iUploadService;

    @PostMapping(path = "/image")
    public ResponseEntity<String> uploadImage(@RequestParam("file")MultipartFile file){
        String url=this.iUploadService.uploadImage(file);
        //若url为空，则返回400,上传失败
        if(StringUtils.isBlank(url)){
            return ResponseEntity.badRequest().build();
        }

        return ResponseEntity.status(HttpStatus.CREATED).body(url);
    }
}

(2)service

接口

package lucky.leyou.upload.service;

import org.springframework.web.multipart.MultipartFile;

public interface IUploadService {

    String uploadImage(MultipartFile file);
}

实现类

package lucky.leyou.upload.service.impl;

import lucky.leyou.upload.service.IUploadService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.multipart.MultipartFile;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

public class UploadServiceImpl implements IUploadService {
    private static final List<String> CONTENT_TYPES = Arrays.asList("image/jpeg", "image/gif");

    private static final Logger LOGGER = LoggerFactory.getLogger(UploadServiceImpl.class);
    @Override
    public String uploadImage(MultipartFile file) {
        String originalFilename = file.getOriginalFilename();
        // 校验文件的类型
        String contentType = file.getContentType();

        //利用浏览器开发者模式下可见的content-type,判断文件类型
        //Content-Type: application/x-www-form-urlencoded
        if (!CONTENT_TYPES.contains(contentType)){
            // 文件类型不合法，直接返回null
            LOGGER.info("文件类型不合法：{}", originalFilename);
            return null;
        }

        try {
            // 校验文件的内容
            BufferedImage bufferedImage = ImageIO.read(file.getInputStream());
            if (bufferedImage == null){
                LOGGER.info("文件内容不合法：{}", originalFilename);
                return null;
            }

            // 保存到服务器
            file.transferTo(new File("C:\\Users\\image\\" + originalFilename));

            // 生成url地址，返回
            return "http://image.leyou.com/" + originalFilename;
        } catch (IOException e) {
            LOGGER.info("服务器内部错误：{}", originalFilename);
            e.printStackTrace();
        }
        return null;
    }
}

(3)使用Nginx代理，实现域名访问

进入Nginx的安装路径E:\toolsoftware\nginx-1.14.0\nginx-1.14.0\conf，修改

添加一个server,如下配置

server {
        listen       80;
        server_name  image.leyou.com;

        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Server $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        location / {
            root C:\\Users\\image;
        }
    }

重新加载Nginx

(4)修改host解析

(5)效果图

(6)修改Nginx配置文件

server {
        listen       80;
        server_name  api.leyou.com;

        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Server $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    # 上传路径的映射
        location /api/upload {    
            proxy_pass http://127.0.0.1:8082;
            proxy_connect_timeout 600;
            proxy_read_timeout 600;
            
            rewrite "^/api/(.*)$" /$1 break; 
        }

        location / {
            proxy_pass http://127.0.0.1:10010;
            proxy_connect_timeout 600;
            proxy_read_timeout 600;
        }

(7)重启nginx，再次上传，发现跟上次的状态码已经不一样了，但是依然报错

不过庆幸的是，这个错误已经不是第一次见了，跨域问题。

package lucky.leyou.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;

/**
 * 利用cors解决跨域问题
 */
@Configuration
public class LeyouCorsConfig {
    @Bean
    public CorsFilter corsFilter() {
        //1.添加CORS配置信息
        CorsConfiguration config = new CorsConfiguration();
        //1) 允许的域,不要写*，否则cookie就无法使用了
        config.addAllowedOrigin("http://manage.leyou.com");
        //2) 是否发送Cookie信息
        config.setAllowCredentials(true);
        //3) 允许的请求方式
        config.addAllowedMethod("*");
        // 4）允许的头信息
        config.addAllowedHeader("*");

        //2.添加映射路径，我们拦截一切请求
        UrlBasedCorsConfigurationSource configSource = new UrlBasedCorsConfigurationSource();
        configSource.registerCorsConfiguration("/**", config);

        //3.返回新的CorsFilter.
        return new CorsFilter(configSource);
    }
}