文件上传
apache 上传组件方案
单文件上传
-
添加依赖
<!--apache组件文件上传--> <!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.3</version> </dependency> -
在springMVC当中要注册一个文件上传解析器
<!--文件上传解析器 id必须为multipartResolver,原因是源代码里面写死了这个名字 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!--单个文件最大上传大小--> <property name="maxUploadSizePerFile" value="20000000"></property> <!--指定上传编码--> <property name="defaultEncoding" value="UTF-8"></property> <!--定义最大文件大小 总的,单位为bytes--> <property name="maxUploadSize" value="200000000"></property> </bean> -
准备上传页面
<form action="${ctx}/file/upload" method="post" enctype="multipart/form-data"> 文件：<input type="file" name="file"> <input type="submit" value="提交"> </form> -
后台
@Controller @RequestMapping("/file") public class FileController { /*在Windows下的路径分隔符（\）和在Linux下的路径分隔符（/）是不一样的， 当直接使用绝对路径时，跨平台会报No Such file or diretory异常。 File.separator能解决这个问题 */ private static String uploadPath = "E:" + File.separator; //入参就可以选择上传的文件 @RequestMapping("/upload") public String upload(@RequestParam("file")MultipartFile multipartFile,Model model){ //1、传到那里去 2、我传什么东西 3、传的细节 System.out.println("uploadPath=" + uploadPath); //1、判断 if(multipartFile != null && !multipartFile.isEmpty()){ //不能为空 //2、获取原始的文件名 String originalFilename = multipartFile.getOriginalFilename(); System.out.println(originalFilename); //3、先截取文件的文件名前缀，不带后缀 String fileNamePrefix = originalFilename.substring(0,originalFilename.lastIndexOf(".")); //4、加工处理文件名，将原文件名+时间戳 String newFileNamePrefix = fileNamePrefix + new Date().getTime(); //5、得到新文件名 String newFileName = newFileNamePrefix + originalFilename.substring(originalFilename.lastIndexOf(".")); //6、构建文件对象 File file = new File(uploadPath + newFileName); //7、上传操作 try { multipartFile.transferTo(file); model.addAttribute("fileName",newFileName); } catch (IOException e) { e.printStackTrace(); } } return "uploadSuc"; } }
多文件上传
@RequestMapping("/upload2")
public String upload2(@RequestParam("file")MultipartFile[] multipartFiles,Model model){
List<String> fileNames = new ArrayList<>();
if(multipartFiles != null && multipartFiles.length > 0){
//遍历
for(MultipartFile multipartFile : multipartFiles){
//1、传到那里去 2、我传什么东西 3、传的细节
System.out.println("uploadPath=" + uploadPath);
//1、判断
if(multipartFile != null && !multipartFile.isEmpty()){
//不能为空
//2、获取原始的文件名
String originalFilename = multipartFile.getOriginalFilename();
System.out.println(originalFilename);
//3、先截取文件的文件名前缀，不带后缀
String fileNamePrefix = originalFilename.substring(0,originalFilename.lastIndexOf("."));
//4、加工处理文件名，将原文件名+时间戳
String newFileNamePrefix = fileNamePrefix + new Date().getTime();
//5、得到新文件名
String newFileName = newFileNamePrefix + originalFilename.substring(originalFilename.lastIndexOf("."));
//6、构建文件对象
File file = new File(uploadPath + newFileName);
//7、上传操作
try {
multipartFile.transferTo(file);
fileNames.add(newFileName);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
model.addAttribute("fileNames",fileNames);
return "uploadSuc2";
}
servlet3.0 文件上传
springmvc中的bean改成
<bean id="multipartResolver" class="org.springframework.web.multipart.support.StandardServletMultipartResolver"></bean>
bean里面的属性只能在web.xml中写或者使用全注解开发模式
xml文件
<servlet>
<!--
这里的servlet-name是有讲究的，
如果我们不去修改spring配置文件默认的位置，
那么springmvc它会去WEB-INF下面找一个叫做springmvc-servlet.xml的文件
-->
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<!--可以重命名springmvc的文件名-->
<param-name>namespace</param-name>
<param-value>springmvc-servlet</param-value>
</init-param>
<init-param>
<!--用来制定上下文的位置-->
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
<!--需要加上这一行-->
<multipart-config>
<max-file-size>200000000</max-file-size>
<max-request-size>2000000000</max-request-size>
</multipart-config>
</servlet>
文件下载
普通方法下载
@RequestMapping("/down2")
public String down2(HttpServletResponse response){
java.io.BufferedInputStream bis = null;
java.io.BufferedOutputStream bos = null;
String filename = "1.jpg";
String downLoadPath = parentPath + filename; //注意不同系统的分隔符
// String downLoadPath =filePath.replaceAll("/", "\\\\\\\\"); //replace replaceAll区别 *****
System.out.println(downLoadPath);
try {
long fileLength = new File(downLoadPath).length();
response.setContentType("application/x-msdownload;");
response.setHeader("Content-disposition", "attachment; filename=" + new String(filename.getBytes("utf-8"), "ISO8859-1"));
response.setHeader("Content-Length", String.valueOf(fileLength));
bis = new BufferedInputStream(new FileInputStream(downLoadPath));
bos = new BufferedOutputStream(response.getOutputStream());
byte[] buff = new byte[2048];
int bytesRead;
while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
bos.write(buff, 0, bytesRead);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bis != null)
try {
bis.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (bos != null)
try {
bos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
使用spring自带的ResponseEntity进行下载
@RequestMapping("/down3")
public ResponseEntity<byte[]> export() throws IOException {
String filename = "1.jpg";
HttpHeaders headers = new HttpHeaders();
File file = new File(parentPath + filename);
if(file.exists()){
headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
headers.setContentDispositionFormData("attachment", filename);
return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),
headers, HttpStatus.CREATED);
}else{
System.out.println(filename+" no exists");
return null;
}
}
