springmvc(2)上传和下载以及静态资源处理

绝地灬酷狼 2022-02-16 16:31 135阅读 0赞

**文件上传**  
导入jar包

![在这里插入图片描述][20190422193849428.png]

jsp页面

xml配置文件

<context:component-scan base-package="com.liy.controller"></context:component-scan>
     	
     	
     	<mvc:annotation-driven></mvc:annotation-driven>
     	
     	<bean class="org.springframework.web.multipart.commons.CommonsMultipartResolver"
    		id="multipartResolver" >
    		
    		
    		<property name="maxUploadSize">
    			<value>5242880</value>
    		</property>
    	</bean>
     
     	
     	<mvc:resources location="/img/" mapping="/img/**"></mvc:resources>

controller层代码

@Controller
    public class UploadController {
    	
    	@RequestMapping("/upload")
    	@ResponseBody
    	public void upload(String name,String address,MultipartFile file) throws IllegalStateException, IOException{
    		
    		System.out.println(name+"--"+address+"--"+file.getOriginalFilename());
    		
    		file.transferTo(new File("d:/img/imgs/"+file.getOriginalFilename()));
    		
    	}

下载的controller代码(两种方式)

@RequestMapping("down")
    	@ResponseBody
    	public void down(HttpServletRequest request , HttpServletResponse response) throws IOException{
    		
    		File file = new File("d:/img/2.png");
    		System.out.println(file.getName());
    		//设置响应头和客户端保存文件名
    	    response.setCharacterEncoding("utf-8");
    	    response.setContentType("multipart/form-data");
    	    response.setHeader("Content-Disposition", "fileName=" + file.getName());
     
    	   //打开本地文件流
           
    		InputStream in = new FileInputStream(file);
    		
    		OutputStream out = response.getOutputStream();
    		
    		byte [] b = new byte[1024]; 
    		
    		int len;
    		 
    		while ((len = in.read(b)) > 0 ) {
    			 out.write(b , 0 ,len);
    			
    		}
    
    		out.close();
    		in.close(); 
    	}
    	
    	@RequestMapping("/down1")
    	public ResponseEntity<byte[]> download(HttpServletRequest request) throws IOException {
    	    // 需要下载的文件
    		File file = new File("d:/img/2.png");
    	    byte[] body = null;
    	    InputStream is = new FileInputStream(file);
    	    body = new byte[is.available()];
    	    is.read(body);
    	    HttpHeaders headers = new HttpHeaders();
    	    headers.add("Content-Disposition", "attchement;filename=" + file.getName());
    	    HttpStatus statusCode = HttpStatus.OK;
    	    
    	    ResponseEntity<byte[]> entity = new ResponseEntity<byte[]>(body, headers, statusCode);
    	    return entity;
    	}

在SpringMVC中，默认情况下，所有的静态资源都会被拦截（js，css。html，图片、视频、音频），对于静态资源，需要手动配置静态资源过滤。  
解决这个问题的方式有两种:

在web.xml中配置default servlet

<servlet-mapping>
      	<servlet-name>default</servlet-name>
      	<url-pattern>*.js</url-pattern>
      </servlet-mapping>
     
      
      <servlet-mapping> 
      	<servlet-name>default</servlet-name>
      	<url-pattern>*.png</url-pattern>
      </servlet-mapping>

在配置文件中通过标签设置

<mvc:resources location="/img/" mapping="/img/**"></mvc:resources>
    
        <mvc:resources location="/js/" mapping="/js/**"></mvc:resources>

[20190422193849428.png]: /images/20220216/9fb3ec4ce3fb4cab92870422753bd5f8.png