Spring Boot (教程十三：附件上传)

GitHub 地址：

https://github.com/asd821300801/Spring-Boot.git

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导入依赖的jar包

• 使用JSP模版

需要在application.properties中配置访问路径

# 页面默认前缀目录
spring.mvc.view.prefix=/WEB-INF/page/
# 响应页面默认后缀
spring.mvc.view.suffix=.jsp

pom.xml 导入以下依赖

 <dependencies>

    
     <dependency>
         <groupId>org.springframework.bootgroupId>
         <artifactId>spring-boot-starter-webartifactId>
     dependency>

    
      <dependency>
        <groupId>org.apache.tomcat.embedgroupId>
        <artifactId>tomcat-embed-jasperartifactId>
        <scope>providedscope>
    dependency>

    <dependency>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-testartifactId>
        <scope>testscope>
    dependency>

dependencies>

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• 使用thymeleaf模版

如果引入thymeleaf模板，那jsp的路径就不生效了，此时文件的路径在：resources/templates/..

pom.xml 导入以下依赖

 <dependencies>
     
     <dependency>
         <groupId>org.springframework.bootgroupId>
         <artifactId>spring-boot-starter-webartifactId>
     dependency>

     
     <dependency>
         <groupId>org.springframework.bootgroupId>
         <artifactId>spring-boot-starter-thymeleafartifactId>
     dependency>

     <dependency>
         <groupId>org.springframework.bootgroupId>
         <artifactId>spring-boot-starter-testartifactId>
         <scope>testscope>
     dependency>
 dependencies>

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注意：如果同时使用两种模版引擎，Spring Boot 默认使用Thymeleaf作为模版引擎

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文件上传控制器

• FileUploadController.java

包所在：com.example.controller

package com.example.controller;


import java.io.File;

import java.io.IOException;
import java.util.UUID;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;



@Controller
@RequestMapping("/upload")
public class FileUploadController {

        /**
         * 上传单个文件
         * 访问路径为：http://ip:port/upload/singleFileUpload.action
         * @return
         */
        @RequestMapping(value = "/singleFileUpload", method = RequestMethod.GET)
        public String singleFileUpload() {
            return "/singleFileUpload";
        }

        /**
         * 上传多个文件
         * 访问路径为：http://ip:port/upload/multipleFilesUpload.action
         * @return
         */
        @RequestMapping(value = "/multipleFilesUpload", method = RequestMethod.GET)
        public String multipleFilesUpload() {
            return "/multipleFilesUpload";
        }



        /**
         * 单文件上传
         * @param file
         * @return
         */
        @RequestMapping(value = "/singleFileUpload", method = RequestMethod.POST)
        @ResponseBody
        public String singleFileUpload(@RequestParam("file") MultipartFile file) {
            if (!file.isEmpty()) {
                //获取源文件名
                String orgName = file.getOriginalFilename();
                System.out.println("原文件名：" + orgName);
                String saveName = UUID.randomUUID() + orgName.substring(orgName.lastIndexOf("."));
                try {
                    file.transferTo(new File("f://image/" + saveName));
                } catch (IllegalStateException | IOException e) {
                    e.printStackTrace();
                }
                return "上传成功。";
            } else {
                return "上传失败。";
            }
        }


        /**
         * 多文件上传
         * @param file
         * @return
         */
        @RequestMapping(value = "/multipleFilesUpload", method = RequestMethod.POST)
        @ResponseBody
        public String multipleFilesUpload(@RequestParam("file") MultipartFile[] files) {
            if(files != null && files.length > 0){
                int num = 0;
                for(int i = 0; i < files.length;i++){
                    if (!files[i].isEmpty()) {
                        //获取源文件名
                        String orgName = files[i].getOriginalFilename();
                        System.out.println("原文件名：" + orgName);
                        String saveName = UUID.randomUUID() + orgName.substring(orgName.lastIndexOf("."));
                        try {
                            files[i].transferTo(new File("f://image/" + saveName));
                        } catch (IllegalStateException | IOException e) {
                            e.printStackTrace();
                        }
                        num += 1;
                    }
                }
                return "上传成功数:" + num;
            }
            return "上传失败。";
        }
}

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文件上传配置器

• FileUploadConfiguration.java

包所在：com.example.configuration

package com.example.configuration;

import javax.servlet.MultipartConfigElement;
import org.springframework.boot.web.servlet.MultipartConfigFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class FileUploadConfiguration {
    @Bean
    public MultipartConfigElement multipartConfigElement() {
        MultipartConfigFactory factory = new MultipartConfigFactory();
        // 设置文件大小限制 ,超出设置页面会抛出异常信息，
        // 这样在文件上传的地方就需要进行异常信息的处理了;
        factory.setMaxFileSize("1024MB"); // KB,MB
        /// 设置总上传数据总大小
        factory.setMaxRequestSize("1024MB");
        // Sets the directory location where files will be stored.设置目录位置的文件将被存储。
        //factory.setLocation("f:/image/");
        return factory.createMultipartConfig();
    }
}

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注意：如果修改了DispatcherServlet默认配置，则需要设置 “多部件配置元素”，
否则上传文件的时候会出现：“Required request part 'file' is not present” ，具体看代码

• 修改的文件： SpringbootHelloApplication.java

    @Autowired
    private MultipartConfigElement multipartConfigElement;//注入 “多部件配置元素”

    /**
     * 修改DispatcherServlet默认配置
     *
     * @param dispatcherServlet
     * @author LingDu
     */
    @Bean
    public ServletRegistrationBean dispatcherRegistration(DispatcherServlet dispatcherServlet) {
        ServletRegistrationBean registration = new ServletRegistrationBean(dispatcherServlet);
        registration.getUrlMappings().clear();

        //这里需要将附件配置设置进去，否则请求不过来 报异常：Required request part 'file' is not present
        registration.setMultipartConfig(multipartConfigElement); 

        registration.addUrlMappings("*.action"); //只有*.action 的请求能通过
        return registration;
    }

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测试

• 上传单个文件

http://localhost:8080/upload/singleFileUpload.action

选择单个文件上传后的结果：

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• 上传多个文件

http://localhost:8080/upload/multipleFilesUpload.action

选择多个文件上传后的结果：

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• 控制台打印如下信息：

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• 到f:/image/目录下查，文件确实是上传上来了。

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工程结构图

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