java后台开发SpringMVC例子--图片上传下载

深碍√TFBOYSˉ_ 2022-06-11 02:26 176阅读 0赞

## java后台开发SpringMVC例子–图片上传下载 ##

### 文章目录 ###

*   *  java后台开发SpringMVC例子--图片上传下载
     *   *  1.配置
         *  2.测试

**环境：**

> win7；jdk1.8\_121；tomact8.0；Mysql；spring-4.3.0。需要安装及配置好jdk，mysql。

**完整代码下载（需要的jar包已放在lib下）**  
：[http://download.csdn.net/download/yhhyhhyhhyhh/9913431][http_download.csdn.net_download_yhhyhhyhhyhh_9913431]

### 1.配置 ###

> 连接数据库需要：`mysql-connector-java-5.0.8-bin.jar`
> 
> 服务器上运行servlet需要：`servlet-api.jar`
> 
> 文件上传需要：
> 
> `com.springsource.org.apache.commons.fileupload-1.2.0.jar`
> 
> `com.springsource.org.apache.commons.io-1.4.0.jar`
> 
> web.xml配置：
> 
>     <?xml version="1.0" encoding="UTF-8"?>
>     <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
>       <display-name>TestOA</display-name>
>       <welcome-file-list>
>         <welcome-file>/WEB-INF/views/index.jsp</welcome-file>
>       </welcome-file-list>
>       <servlet>  
>             <servlet-name>oa</servlet-name>  
>             <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>  
>               
>             <load-on-startup>1</load-on-startup>  
>         </servlet>  
>         <servlet-mapping>  
>             <servlet-name>oa</servlet-name>  
>               
>               
>             <url-pattern>/</url-pattern>  
>          </servlet-mapping>  
>          
>         <filter>
>             <filter-name>encodingFilter</filter-name>
>             <filter-class>org.springframework.web.filter.CharacterEncodingFilter </filter-class>
>             <init-param>
>                 <param-name>encoding</param-name>
>                 <param-value>UTF-8</param-value>
>             </init-param>
>         </filter>
>         <filter-mapping>
>             <filter-name>encodingFilter</filter-name>
>             <url-pattern>/</url-pattern>
>         </filter-mapping>
>     </web-app>
> 
> servlet配置（这里为：oa-servlet.xml）
> 
>     <?xml version="1.0" encoding="UTF-8"?>
>     <beans xmlns="http://www.springframework.org/schema/beans"
>     	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>     	xmlns:context="http://www.springframework.org/schema/context"
>     	xmlns:p="http://www.springframework.org/schema/p"
>     	xmlns:mvc="http://www.springframework.org/schema/mvc"
>     	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
>     		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
>     		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">
>     	
>     	<context:component-scan base-package="com.springmvc.test" />  
>       
>       
>         <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
>             <property name="prefix" value="/WEB-INF/views/" />  
>             <property name="suffix" value=".jsp" />  
>         </bean>  
>          
>         <bean id="multipartResolver"
>         class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
>         
>         <property name="maxUploadSize" value="12345678900"/>
>             <property name="maxInMemorySize" value="10240100"/>
>             <property name="defaultEncoding" value="UTF-8"/>
>     </bean>
>     </beans>
> 
> 数据库信息：
> 
> ![这里写图片描述][SouthEast]

核心代码部分。

package com.springmvc.test;
    import java.io.File;
    import java.io.IOException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    import javax.servlet.http.HttpServletRequest;
    import org.apache.commons.io.FileUtils;
    import org.springframework.http.HttpHeaders;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.MediaType;
    import org.springframework.http.ResponseEntity;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.multipart.commons.CommonsMultipartFile;
    
    /*
     * @Controller表示类注解
     * @RequestMapping表示controller指定的URL
     * @RequestParam：根据参数名从URL中取得参数值
     */
    @Controller
    public class UpDownLoad {
    	@RequestMapping("/login")  
    	 public String login(@RequestParam("username") String name, @RequestParam("password") String pass,
    	            Model model) {  
    		 LoginModel newModel=new LoginModel();
    		newModel.setName(name);
    		newModel.setPas(pass);
    		if(newModel.login())
    		{
    			model.addAttribute("username", name);//传递参数
    		    return "menu";
    		}
    		else
    		{   model.addAttribute("username", name);
    		    return "index";
    		}
    	  }
    	     @RequestMapping("/fileupload")
    	     public String upload(@RequestParam("image") CommonsMultipartFile image ,
    	    		 HttpServletRequest request) throws IllegalStateException, IOException  {
    	         //解析路径
    	         String imgFolder =request.getSession().getServletContext().getRealPath("/fileupload");
    	         //解析文件名
    	         String imgUrl = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date())+image.getOriginalFilename();
    	         //新建file对象
    	         File targetImg = new File(imgFolder ,imgUrl);
    	        	 String type=null;// 文件类型
    	        	 type=imgUrl.indexOf(".")!=-1?imgUrl.substring(imgUrl.lastIndexOf(".")+1, imgUrl.length()):null;
    	        	 if (type!=null) 
    	        	 {// 判断文件类型是否为空
    	        		 
    	        	 if ("GIF".equals(type.toUpperCase())||"PNG".equals(type.toUpperCase())||"JPG".equals(type.toUpperCase())) 
    	        	 {
    	    	         //判断文件是否存在
    	    	         if (!targetImg.exists()){
    	    	             targetImg.mkdirs();//不存在新建
    	    	         }
    	    	        image.transferTo(targetImg);
    	    	         return "upsuccess";
    	        	 }
    	        	 }
    	        	 return "upfail";
    	     }
    	     @RequestMapping("/filedownload")
    	     public ResponseEntity<byte[]> download() throws IOException {  
    	    	    HttpHeaders headers = new HttpHeaders();  
    	    	   // String fileUrl="D:\\test.txt";
    	    	   String fileUrl="D:\\test.jpg";
    	    	    File file= new File(fileUrl);
    	    	    headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);  
    	    	    String charset=new String(fileUrl.getBytes("utf-8"),"iso-8859-1");
    	    	    headers.setContentDispositionFormData("file", charset);  
    	    	    return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),  
    	    	                                      headers, HttpStatus.CREATED);
    	     } 
    }

### 2.测试 ###

** 图片上传:**

![这里写图片描述][SouthEast 1]

![这里写图片描述][SouthEast 2]  
![这里写图片描述][SouthEast 3]

**图片下载：**  
![这里写图片描述][SouthEast 4]

**文件下载：**  
![这里写图片描述][SouthEast 5]

[http_download.csdn.net_download_yhhyhhyhhyhh_9913431]: http://download.csdn.net/download/yhhyhhyhhyhh/9913431
[SouthEast]: /images/20220611/2da2baea3816487bb1d35014e47d9f62.png
[SouthEast 1]: /images/20220611/640355094f294f8f8dd57b7b2837d0f6.png
[SouthEast 2]: /images/20220611/f33d2a0c1ff14cd881e87fc2a84dd4c4.png
[SouthEast 3]: /images/20220611/6a7037fe4f064c4fa45825c31970020e.png
[SouthEast 4]: /images/20220611/1eca1a7b9ecf404faa5c781d38acce46.png
[SouthEast 5]: /images/20220611/5dff152baff044cc98a18a4504b39037.png