Spring boot实现文件上传实例(多文件上传)

时间:2022-09-22 22:55:10

文件上传主要分以下几个步骤:

(1)新建maven java project;

(2)在pom.xml加入相应依赖;

(3)新建一个表单页面(这里使用thymleaf);

(4)编写controller;

(5)测试;

(6)对上传的文件做一些限制;

(7)多文件上传实现

(1)新建maven Java project

新建一个名称为spring-boot-fileupload maven Java项目;

(2)在pom.xml加入相应依赖;

加入相应的maven依赖,具体看以下解释:

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<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">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.example</groupId>
 <artifactId>spring-boot-fileupload</artifactId>
 <version>0.0.1-SNAPSHOT</version>
  
 <!--
    spring boot 父节点依赖,
        引入这个之后相关的引入就不需要添加version配置,
    spring boot会自动选择最合适的版本进行添加。
   -->
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.0.RELEASE</version>
  </parent>
 
 <dependencies>
    <!-- spring boot web支持:mvc,aop... -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
 
    <!-- thmleaf模板依赖. -->
    <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
 </dependencies>
 
  <build>
    <plugins>
      <!-- 编译版本; -->
      <plugin>
       <artifactId>maven-compiler-plugin</artifactId>
       <configuration>
         <source>1.7</source>
         <target>1.7</target>
       </configuration>
      </plugin>
    </plugins>
  </build>
</project>

(3)新建一个表单页面(这里使用thymleaf)

在src/main/resouces新建templates,在templates下新建一个file.html:

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<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
  xmlns:th="http://www.thymeleaf.org"
  xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
<head>
<title>Hello World!</title>
</head>
<body>
  <form method="POST" enctype="multipart/form-data" action="/upload">
    <p>
      文件:<input type="file" name="file" />
    </p>
    <p>
      <input type="submit" value="上传" />
    </p>
  </form>
</body>
</html>

(4)编写controller;

编写controller进行测试,这里主要实现两个方法:其一就是提供访问的/file路径;其二就是提供post上传的/upload方法,具体看代码实现:

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@Controller
public class FileUploadController {
  // 访问路径为:http://127.0.0.1:8080/file
  @RequestMapping("/file")
  public String file() {
    return "/file";
  }
 
  /**
   * 文件上传具体实现方法;
   
   * @param file
   * @return
   */
  @RequestMapping("/upload")
  @ResponseBody
  public String handleFileUpload(@RequestParam("file") MultipartFile file) {
    if (!file.isEmpty()) {
      try {
        /*
         * 这段代码执行完毕之后,图片上传到了工程的跟路径; 大家自己扩散下思维,如果我们想把图片上传到
         * d:/files大家是否能实现呢? 等等;
         * 这里只是简单一个例子,请自行参考,融入到实际中可能需要大家自己做一些思考,比如: 1、文件路径; 2、文件名;
         * 3、文件格式; 4、文件大小的限制;
         */
 
        BufferedOutputStream out = new BufferedOutputStream(
            new FileOutputStream(new File(
                file.getOriginalFilename())));
        out.write(file.getBytes());
        out.flush();
        out.close();
 
      } catch (FileNotFoundException e) {
        e.printStackTrace();
        return "上传失败," + e.getMessage();
      } catch (IOException e) {
        e.printStackTrace();
        return "上传失败," + e.getMessage();
      }
 
      return "上传成功";
 
    } else {
      return "上传失败,因为文件是空的.";
    }
  }
   
  // 访问路径为:http://127.0.0.1:8080/file
    @RequestMapping("/mutifile")
    public String mutifile() {
      return "/mutifile";
    }

(5)编写Application.java然后测试

Application没什么代码,就是Spring Boot的启动配置,具体如下:

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package com.example.controller;
 
import javax.servlet.MultipartConfigElement;
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
//import org.springframework.boot.context.embedded.MultipartConfigFactory;
import org.springframework.boot.web.servlet.MultipartConfigFactory;
import org.springframework.context.annotation.Bean;
 
@SpringBootApplication
public class Application {
  public static void main(String[] args) {
     SpringApplication.run(Application.class, args);
  }
   
}

然后你就可以访问:http://127.0.0.1:8080/file 进行测试了,文件上传的路径是在工程的跟路径下,请刷新查看,其它的请查看代码中的注释进行自行思考

(6)对上传的文件做一些限制;

对文件做一些限制是有必要的,在Application.java进行编码配置:。 

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@Bean
  public MultipartConfigElement multipartConfigElement() { 
      MultipartConfigFactory factory = new MultipartConfigFactory();
      //// 设置文件大小限制 ,超了,页面会抛出异常信息,这时候就需要进行异常信息的处理了;
      factory.setMaxFileSize("128KB"); //KB,MB
      /// 设置总上传数据总大小
      factory.setMaxRequestSize("256KB"); 
      //Sets the directory location where files will be stored.
      //factory.setLocation("路径地址");
      return factory.createMultipartConfig(); 
  }

(7)多文件上传实现

多文件对于前段页面比较简单,具体代码实现:

在src/resouces/templates/mutifile.html

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<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"
   xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
  <head>
    <title>Hello World!</title>
  </head>
  <body>
    <form method="POST" enctype="multipart/form-data" action="/batch/upload"
      <p>文件1:<input type="file" name="file" /></p>
      <p>文件2:<input type="file" name="file" /></p>
      <p>文件3:<input type="file" name="file" /></p>
      <p><input type="submit" value="上传" /></p>
    </form>
  </body>
</html>

FileUploadController中新增两个方法:

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// 访问路径为:http://127.0.0.1:8080/mutifile
    @RequestMapping("/mutifile")
    public String mutifile() {
      return "/mutifile";
    }
 
  /**
   * 多文件具体上传时间,主要是使用了MultipartHttpServletRequest和MultipartFile
   
   * @param request
   * @return
   */
 
  @RequestMapping(value = "/batch/upload", method = RequestMethod.POST)
  @ResponseBody
  public String handleFileUpload(HttpServletRequest request) {
    List<MultipartFile> files = ((MultipartHttpServletRequest) request)
        .getFiles("file");
    MultipartFile file = null;
    BufferedOutputStream stream = null;
    for (int i = 0; i < files.size(); ++i) {
      file = files.get(i);
      if (!file.isEmpty()) {
        try {
          byte[] bytes = file.getBytes();
          stream = new BufferedOutputStream(new FileOutputStream(
              new File(file.getOriginalFilename())));
          stream.write(bytes);
          stream.close();
 
        } catch (Exception e) {
          stream = null;
          return "You failed to upload " + i + " => "
              + e.getMessage();
 
        }
      } else {
        return "You failed to upload " + i
            + " because the file was empty.";
      }
 
    }
    return "upload successful";
 
  }

访问路径:http://127.0.0.1:8080/mutifile 进行测试。

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。

原文链接:http://blog.csdn.net/u014695188/article/details/52398239