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Spring boot实现文件上传功能

程序员文章站 2024-02-13 23:30:46
本文实例为大家分享了spring boot实现文件上传的具体代码，供大家参考，具体内容如下 1. 创建一个maven的web工程，然后配置pom.xml文件，增加依赖：...

本文实例为大家分享了spring boot实现文件上传的具体代码，供大家参考，具体内容如下

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

<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：

<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>

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：

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 ：

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

<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：

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。

参考资料：multipartresolver实现文件上传功能

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。

1. multipartresolver也可以实现文件上传功能。参考文章：

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