Spring实现文件上传功能

时间:2022-10-16 16:40:12

本篇文章,我们要来做一个Spring的文件上传功能:

1. 创建一个Maven的web工程,然后配置pom.xml文件,增加依赖:

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<dependency>
 
  <groupId>org.springframework.boot</groupId>
 
  <artifactId>spring-boot-starter-web</artifactId>
 
  <version>1.0.2.RELEASE</version>
 
</dependency>

2.在webapp目录下的index.jsp文件中输入一个表单:

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<html>
 
<body>
 
<form method="POST" enctype="multipart/form-data"
 
   action="/upload">
 
  File to upload: <input type="file" name="file"><br /> Name: <input
 
    type="text" name="name"><br /> <br /> <input type="submit"
 
                           value="Upload"> Press here to upload the file!
 
</form>
 
</body>
 
</html>

这个表单就是我们模拟的上传页面。

3. 编写处理这个表单的Controller:

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import java.io.BufferedOutputStream;
 
import java.io.File;
 
import java.io.FileOutputStream;
 
 
 
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
 
public class FileUploadController {
 
 
 
  @RequestMapping(value="/upload", method=RequestMethod.GET)
 
  public @ResponseBody String provideUploadInfo() {
 
    return "You can upload a file by posting to this same URL.";
 
  }
 
 
 
  @RequestMapping(value="/upload", method=RequestMethod.POST)
 
  public @ResponseBody String handleFileUpload(@RequestParam("name") String name,
 
      @RequestParam("file") MultipartFile file){
 
    if (!file.isEmpty()) {
 
      try {
 
        byte[] bytes = file.getBytes();
 
        BufferedOutputStream stream =
 
            new BufferedOutputStream(new FileOutputStream(new File(name + "-uploaded")));
 
        stream.write(bytes);
 
        stream.close();
 
        return "You successfully uploaded " + name + " into " + name + "-uploaded !";
 
      } catch (Exception e) {
 
        return "You failed to upload " + name + " => " + e.getMessage();
 
      }
 
    } else {
 
      return "You failed to upload " + name + " because the file was empty.";
 
    }
 
  }
 
 
 
}

4. 然后我们对上传的文件做一些限制,同时编写main方法来启动这个web :

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import org.springframework.boot.SpringApplication;
 
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 
import org.springframework.boot.context.embedded.MultiPartConfigFactory;
 
import org.springframework.context.annotation.Bean;
 
import org.springframework.context.annotation.ComponentScan;
 
import org.springframework.context.annotation.Configuration;
 
 
 
import javax.servlet.MultipartConfigElement;
 
 
 
@Configuration
 
@ComponentScan
 
@EnableAutoConfiguration
 
public class Application {
 
 
 
  @Bean
 
  public MultipartConfigElement multipartConfigElement() {
 
    MultiPartConfigFactory factory = new MultiPartConfigFactory();
 
    factory.setMaxFileSize("128KB");
 
    factory.setMaxRequestSize("128KB");
 
    return factory.createMultipartConfig();
 
  }
 
 
 
  public static void main(String[] args) {
 
    SpringApplication.run(Application.class, args);
 
  }
 
}

5. 然后访问http://localhost:8080/upload就可以看到页面了。

上面的例子是实现的是单个文件上传的功能,假定我们现在要实现文件批量上传的功能的话,我们只需要简单的修改一下上面的代码就行,考虑到篇幅的问题,下面只是贴出和上面不同的代码,没有贴出的说明和上面一样。:

1.  新增batchUpload.jsp文件

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<html>
 
<body>
 
<form method="POST" enctype="multipart/form-data"
 
   action="/batch/upload">
 
  File to upload: <input type="file" name="file"><br />
 
  File to upload: <input type="file" name="file"><br />
 
  <input type="submit" value="Upload"> Press here to upload the file!
 
</form>
 
</body>
 
</html>

2. 新增BatchFileUploadController.java文件:

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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.ResponseBody;
 
import org.springframework.web.multipart.MultipartFile;
 
import org.springframework.web.multipart.MultipartHttpServletRequest;
 
 
 
import javax.servlet.http.HttpServletRequest;
 
import java.io.BufferedOutputStream;
 
import java.io.File;
 
import java.io.FileOutputStream;
 
import java.util.List;
 
 
 
/**
 
 * Created by wenchao.ren on 2014/4/26.
 
 */
 
 
 
@Controller
 
public class BatchFileUploadController {
 
 
 
  @RequestMapping(value="/batch/upload", method= RequestMethod.POST)
 
  public @ResponseBody
 
  String handleFileUpload(HttpServletRequest request){
 
    List<MultipartFile> files = ((MultipartHttpServletRequest)request).getFiles("file");
 
    for (int i =0; i< files.size(); ++i) {
 
      MultipartFile file = files.get(i);
 
      String name = file.getName();
 
      if (!file.isEmpty()) {
 
        try {
 
          byte[] bytes = file.getBytes();
 
          BufferedOutputStream stream =
 
              new BufferedOutputStream(new FileOutputStream(new File(name + i)));
 
          stream.write(bytes);
 
          stream.close();
 
        } catch (Exception e) {
 
          return "You failed to upload " + name + " => " + e.getMessage();
 
        }
 
      } else {
 
        return "You failed to upload " + name + " because the file was empty.";
 
      }
 
    }
 
    return "upload successful";
 
  }
 
}

这样一个简单的批量上传文件的功能就ok了,是不是很简单啊。 

注意:上面的代码只是为了演示而已,所以编码风格上采取了随性的方式,不建议大家模仿。

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://www.cnblogs.com/rollenholt/p/3693087.html