java后台开发SpringMVC例子--图片上传下载

java后台开发SpringMVC例子–图片上传下载

• • java后台开发SpringMVC例子图片上传下载

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

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：表示启动容器时初始化该Servlet； -->  
        <load-on-startup>1</load-on-startup>  
    </servlet>  
    <servlet-mapping>  
        <servlet-name>oa</servlet-name>  
        <!-- url-pattern：表示哪些请求交给Spring Web MVC处理， “/” 是用来定义默认servlet映射的。 -->  
        <!-- 也可以如“*.html”表示拦截所有以html为扩展名的请求。 -->  
        <url-pattern>/</url-pattern>  
     </servlet-mapping>  
    <!-- 编码过滤器 --> 
    <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">
  <!-- spring扫描注解的包 -->
  <context:component-scan base-package="com.springmvc.test" />  
<!-- 在Spring配置文件中配置ViewResolver -->  
<!-- InternalResourceViewResolver：用于支持Servlet、JSP视图解析；    
     prefix和suffix：查找视图页面的前缀和后缀（前缀[逻辑视图名]后缀），  
     比如传进来的逻辑视图名为hello，则该该jsp视图页面应该存放在“WEB-INF/views/hello.jsp”；    -->  
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
        <property name="prefix" value="/WEB-INF/views/" />  
        <property name="suffix" value=".jsp" />  
    </bean>  
     <!--文件上传解析器配置 -->
    <bean id="multipartResolver"
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <!-- 上传文件的总大小和单个文件的大小 -->
    <property name="maxUploadSize" value="12345678900"/>
        <property name="maxInMemorySize" value="10240100"/>
        <property name="defaultEncoding" value="UTF-8"/>
</bean>
</beans>

数据库信息：

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:

​

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文件下载：