6、SpringMVC实现文件上传下载
SpringMVC-servlet.xml
使用springMVC来处理文件上传和下载须要添加以下的配置文件，并且id是固定的
能够到org.springframework.web.servlet.DispatcherServlet的源码文件下查看
CommonsMultipartResolver提供三个属性设置，能够跳转到源码开头的注释查看
SpringMVC-servlet.xml中添加如下：html
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="DefaultEncoding" value="UTF-8" />
<property name="MaxUploadSize" value="1048576" />
<property name="MaxInMemorySize" value="4096"/>
</bean>
CommonsMultipartResolver源码注释部分片断：java
/**
* Servlet-based {@link MultipartResolver} implementation for
* <a href="http://commons.apache.org/proper/commons-fileupload">Apache Commons FileUpload</a>
* 1.2 or above.
*
* <p>Provides "maxUploadSize", "maxInMemorySize" and "defaultEncoding" settings as
* bean properties (inherited from {@link CommonsFileUploadSupport}). See corresponding
* ServletFileUpload / DiskFileItemFactory properties ("sizeMax", "sizeThreshold",
* "headerEncoding") for details in terms of defaults and accepted values.
*
* <p>Saves temporary files to the servlet container's temporary directory.
* Needs to be initialized <i>either</i> by an application context <i>or</i>
* via the constructor that takes a ServletContext (for standalone usage).
*/
public class CommonsMultipartResolver extends CommonsFileUploadSupport{}
springmvc的DispatcherServlet部分源码web
/** Well-known name for the MultipartResolver object in the bean factory for this namespace. */
public static final String MULTIPART_RESOLVER_BEAN_NAME = "multipartResolver";
/** Well-known name for the LocaleResolver object in the bean factory for this namespace. */
public static final String LOCALE_RESOLVER_BEAN_NAME = "localeResolver";
/** Well-known name for the ThemeResolver object in the bean factory for this namespace. */
public static final String THEME_RESOLVER_BEAN_NAME = "themeResolver";
/**
* Well-known name for the HandlerMapping object in the bean factory for this namespace.
* Only used when "detectAllHandlerMappings" is turned off.
* @see #setDetectAllHandlerMappings
*/
public static final String HANDLER_MAPPING_BEAN_NAME = "handlerMapping";
/**
* Well-known name for the HandlerAdapter object in the bean factory for this namespace.
* Only used when "detectAllHandlerAdapters" is turned off.
* @see #setDetectAllHandlerAdapters
*/
public static final String HANDLER_ADAPTER_BEAN_NAME = "handlerAdapter";
/**
* Well-known name for the HandlerExceptionResolver object in the bean factory for this namespace.
* Only used when "detectAllHandlerExceptionResolvers" is turned off.
* @see #setDetectAllHandlerExceptionResolvers
*/
public static final String HANDLER_EXCEPTION_RESOLVER_BEAN_NAME = "handlerExceptionResolver";
/**
* Well-known name for the RequestToViewNameTranslator object in the bean factory for this namespace.
*/
public static final String REQUEST_TO_VIEW_NAME_TRANSLATOR_BEAN_NAME = "viewNameTranslator";
/**
* Well-known name for the ViewResolver object in the bean factory for this namespace.
* Only used when "detectAllViewResolvers" is turned off.
* @see #setDetectAllViewResolvers
*/
public static final String VIEW_RESOLVER_BEAN_NAME = "viewResolver";
/**
* Well-known name for the FlashMapManager object in the bean factory for this namespace.
*/
public static final String FLASH_MAP_MANAGER_BEAN_NAME = "flashMapManager";
文件上传逻辑java文件： UploadController.java
package main.java.com.smart.web;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
@Controller
public class UploadController {
@Resource
HttpServletRequest request;
/**
* @return 返回相对路径RelativePath
*/
public String RelPath() {
String path = request.getContextPath();
return request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
}
/**
* @return 返回服务器目录的真实路径
*/
public String RealPath() {
return request.getSession().getServletContext().getRealPath("/");
}
/**
* 单文件上传
*
* @param imageFile
* @param request
* @return
*/
@RequestMapping("/singleUpload")
public String singleUpload(@RequestParam("imageFile") MultipartFile imageFile, HttpServletRequest request){//,
String filename = imageFile.getOriginalFilename();
File dir = new File(RealPath()+"upload/");//1.新建一个文件夹对象
if(!dir.exists()){ //2.检查路径下upload文件夹是否存在
dir.mkdirs();
}
System.out.println("文件上传到:"+RelPath()+"upload/"+ filename);
File targetFile = new File(RealPath()+"upload/"+ filename);//3.在文件夹下新建一个filename文件的文件对象,此处新建文件应该新建在确切的物理路径下
if(!targetFile.exists()){//4.判断真实路径下是否存在filename文件
try {
targetFile.createNewFile();//5.在真实路径下建立filename空文件
} catch (IOException e) {
e.printStackTrace();
}
}
try {
imageFile.transferTo(targetFile);//6.复制文件到真实路径下
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("真实路径:"+RealPath()+"upload/");
System.out.println("相对路径:"+RelPath()+"upload/");
return "redirect:"+RelPath()+"upload/"+filename; //非安全目录下使用(可用)
//return "redirect:"+RealPath()+"upload/"+filename; //重定向到真实地址(不可用)
//return "redirect:http://localhost:8080/SpringMvcTest/upload/"+filename;
}
/**
* 多文件上传
* @param request
* @return
*/
@RequestMapping("/multiUpload")
public String multiUpload(HttpServletRequest request){
MultipartHttpServletRequest multipartHttpServletRequest = (MultipartHttpServletRequest)request;//一、将请求进行转义
Map<String, MultipartFile> files = multipartHttpServletRequest.getFileMap();//二、获取同一表单提交过来的全部文件
//三、在真实路径建立文件
File dir = new File(RealPath()+"upload/");
if(!dir.exists()) {
dir.mkdirs();
}
List<String> fileList = new ArrayList<String>();//四、将上传的文件的相对地址保存在一个列表中(客户端只能请求服务器的相对地址)
for(MultipartFile file : files.values()) { //五、在服务器的绝对地址下新建文件,并将上传的文件复制过去,将相对路径保存进List列表中,服务器的相对路径和绝对路径是相互映射的，客户端只能请求相对路径
File targetFile = new File(RealPath()+"upload/" + file.getOriginalFilename());
if(!targetFile.exists()) {
try {
targetFile.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
try {
file.transferTo(targetFile);
fileList.add(RelPath()+"upload/"+file.getOriginalFilename());
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}else{
fileList.add(RelPath()+"upload/"+file.getOriginalFilename());//文件若是存在直接访问
}
}
System.out.println(fileList);
request.setAttribute("files", fileList);
return "/WEB-INF/jsp/multiUploadResult.jsp";
}
}
singleUpload.jsp(WEB-INF安全目录下)
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<base href="<%=basePath%>">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>单文件 上传</title>
</head>
<body>
<div style="margin: 0 auto;margin-top: 100px;">
<form action="singleUpload.html" method="post" enctype="multipart/form-data">
<p>
<span>文件:</span>
<input type="file" name="imageFile">
</p>
<p>
<input type="submit">
</p>
</form>
</div>
</body>
</html>
multiUpload.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<base href="<%=basePath%>">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>多文件上传</title>
</head>
<body>
<div style="margin: 0 auto;margin-top: 100px; ">
<form action="multiUpload.html" method="post" enctype="multipart/form-data">
<p>
<span>文件1：</span>
<input type="file" name="imageFile1">
</p>
<p>
<span>文件2：</span>
<input type="file" name="imageFile2">
</p>
<p>
<input type="submit">
</p>
</form>
</div>
</body>
</html>
multiUploadResult.jsp
<%@page import="java.util.List" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<base href="<%=basePath%>">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>多文件 上传结果</title>
</head>
<body>
<div style="margin: 0 auto;margin-top: 100px; ">
<p>${files}</p>
<%
List<String> fileList = (List)request.getAttribute("files");
for(String url : fileList){
%>
<p><%=url %></p><br>
<a href="<%=url %>">
<img alt="" src="<%=url %>">
</a>
<%
}
%>
</div>
</body>
</html>
文件下载
package main.java.com.smart.web;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
@Controller
public class DownloadController {
@Resource
HttpServletRequest request;
@Resource
HttpServletResponse response;
@RequestMapping("/download")
public String download(@RequestParam String fileName){
response.setContentType("text/html;charset=utf-8");//1.设置响应的文件类型和文件编码
try {
request.setCharacterEncoding("UTF-8");//2.确保请求的编码类型为UTF-8,否则文件下载后有可能由于类型不一致出现乱码
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
BufferedInputStream bis = null;
BufferedOutputStream bos = null;
String ctxPath = request.getSession().getServletContext().getRealPath("/")+"upload/";
String downLoadPath = ctxPath + fileName;
System.out.println(downLoadPath);
try{
long fileLength = new File(downLoadPath).length();
//3.设置响应头文件内容,文件类型、弹出下载对话框、文件大小
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));//4.新建一个输入流缓存对象,并将文件输入流对象传递进去,将文件路径传递进文件输入流对象中，这是一个逐步处理的过程
bos = new BufferedOutputStream(response.getOutputStream());//5.新建一个输出流缓存对象,将服务器响应输出流对象至于其中
byte[] buff = new byte[2048];//6.新建一个缓存
int bytesRead; //7.内容字节总数
while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {//8.输入到到buff缓存中,当文件为空是read()会return -1,不然返回读取的字节总数
bos.write(buff, 0, bytesRead);//9.将buff的字节写到响应体的输出流中，输出流持续输出到客户端
}
} catch(Exception e) {
e.printStackTrace();
} finally {
if (bis != null)
try {
bis.close();//10.关闭缓存输入流对象
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (bos != null)
try {
bos.close();//10.关闭缓存输出流对象
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
}
请求方式举栗
<a href="download.html?fileName='文件名'">下载文件 </a>
多文件上传Web截图示例：
原创+装载，若有侵权请指出立马处理spring