Spring mvc 檔案的上傳與下載
阿新 • • 發佈:2019-02-05
一、檔案上傳
首先寫一個form表單,用來提交要上傳的檔案。程式碼如下:
<form method="post" action="<%=request.getContextPath()%>/file/fileUpLoad1.html" enctype="multipart/form-data">
<input type="file" name="file"/>
<input type="submit" value="上傳">
</form>
檔案上傳的表單中,必須要有enctype=multipart/form-data
後臺接收上傳的檔案有三種方式:
1、利用commons-fileupload. jar包中FileUtils類的copyInputStreamToFile方法進行檔案的讀寫
@RequestMapping(value="/fileUpLoad1", method=RequestMethod.POST) public String fileUpLoad1(@RequestParam("file") MultipartFile file, HttpServletRequest request, ModelMap modelMap) { logger.info("***************************進入檔案上傳請求***********************"); String viewName = ""; try { if (file.isEmpty()) {//如果還沒有選擇檔案,則跳轉到提示頁面 logger.info("***************************上傳檔案為空***********************"); modelMap.put("errorMsg", "請選擇檔案後上傳"); viewName = "error"; }else{ //檔案存放路勁,上傳的檔案放在專案的upload資料夾下 String savePath = request.getSession().getServletContext().getRealPath("/upload"); String realName = file.getOriginalFilename(); //日誌列印上傳檔案的資訊 logger.info("***************************[realName:"+realName+"]***********************"); logger.info("***************************[fileName:"+file.getName()+"]***********************"); logger.info("***************************[fileSize:"+file.getSize()/1024+"KB]***********************"); logger.info("***************************[fileType:"+file.getContentType()+"]***********************"); //將檔案資訊存放到modelMap中,在成功頁面讀取檔案資訊 modelMap.put("fileName", realName); modelMap.put("fileSize", file.getSize()/1024+"KB"); modelMap.put("fileType", file.getContentType()); modelMap.put("filePath", savePath); //將上傳的檔案存放到upload下 FileUtils.copyInputStreamToFile(file.getInputStream(), new File(savePath + File.separator + realName)); logger.info("***************************上傳檔案為空***********************"); viewName = "success"; } } catch (Exception e) { logger.error(e.getMessage(), e); logger.info("***************************檔案上傳失敗***********************"); modelMap.put("errorMsg", "檔案上傳失敗"); return "error"; } return viewName; }
2、利用FileOutputStream和FileInputStream進行檔案的讀寫
@RequestMapping(value="/fileUpLoad2", method=RequestMethod.POST) public String fileUpLoad2(@RequestParam("file") MultipartFile file, HttpServletRequest request, ModelMap modelMap){ String viewName = ""; OutputStream os = null; InputStream is = null; logger.info("***************************進入檔案上傳請求***********************"); try{ if (file.isEmpty()) {//如果還沒有選擇檔案,則跳轉到提示頁面 logger.info("***************************上傳檔案為空***********************"); modelMap.put("errorMsg", "請選擇檔案後上傳"); viewName = "error"; }else{ //檔案存放路勁,上傳的檔案放在專案的upload資料夾下 String savePath = request.getSession().getServletContext().getRealPath("/upload"); String realName = file.getOriginalFilename(); //日誌列印上傳檔案的資訊 logger.info("***************************[realName:"+realName+"]***********************"); logger.info("***************************[fileName:"+file.getName()+"]***********************"); logger.info("***************************[fileSize:"+file.getSize()/1024+"KB]***********************"); logger.info("***************************[fileType:"+file.getContentType()+"]***********************"); //將檔案資訊存放到modelMap中,在成功頁面讀取檔案資訊 modelMap.put("fileName", realName); modelMap.put("fileSize", file.getSize()/1024+"KB"); modelMap.put("fileType", file.getContentType()); modelMap.put("filePath", savePath); //將上傳的檔案存放到upload下 os = new FileOutputStream(savePath+File.separator+realName); is = file.getInputStream(); int len = 0; byte[] buffer = new byte[1024]; while((len = is.read(buffer))!=-1){ os.write(buffer,0,len); } logger.info("***************************上傳檔案為空***********************"); viewName = "success"; } }catch(Exception e){ logger.error(e.getMessage(), e); logger.info("***************************檔案上傳失敗***********************"); modelMap.put("errorMsg", "檔案上傳失敗"); return "error"; }finally{ if(os != null){ try { os.close(); } catch (IOException e) { e.printStackTrace(); } } if(is != null){ try { is.close(); } catch (IOException e) { e.printStackTrace(); } } } return viewName; }
3、利用spring mvc MultipartFile的Transto方法
@RequestMapping(value="/fileUpLoad3", method=RequestMethod.POST)
public String fileUpLoad3(@RequestParam("file") MultipartFile file, HttpServletRequest request, ModelMap modelMap){
String viewName = "";
logger.info("***************************進入檔案上傳請求***********************");
try{
if (file.isEmpty()) {//如果還沒有選擇檔案,則跳轉到提示頁面
logger.info("***************************上傳檔案為空***********************");
modelMap.put("errorMsg", "請選擇檔案後上傳");
viewName = "error";
}else{
//檔案存放路勁,上傳的檔案放在專案的upload資料夾下
String savePath = request.getSession().getServletContext().getRealPath("/upload");
String realName = file.getOriginalFilename();
//日誌列印上傳檔案的資訊
logger.info("***************************[realName:"+realName+"]***********************");
logger.info("***************************[fileName:"+file.getName()+"]***********************");
logger.info("***************************[fileSize:"+file.getSize()/1024+"KB]***********************");
logger.info("***************************[fileType:"+file.getContentType()+"]***********************");
//將檔案資訊存放到modelMap中,在成功頁面讀取檔案資訊
modelMap.put("fileName", realName);
modelMap.put("fileSize", file.getSize()/1024+"KB");
modelMap.put("fileType", file.getContentType());
modelMap.put("filePath", savePath);
//將上傳的檔案存放到upload下
file.transferTo(new File(savePath + File.separator + realName));
logger.info("***************************上傳檔案為空***********************");
viewName = "success";
}
}catch(Exception e){
logger.error(e.getMessage(), e);
logger.info("***************************檔案上傳失敗***********************");
modelMap.put("errorMsg", "檔案上傳失敗");
return "error";
}
return viewName;
}
spring mvc 檔案上傳主要用到的是MultipartFile,用MultipartResolver解析器來解析,所以配置檔案中必須要有如下配置:
<!-- 檔案上傳解析器 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 允許檔案上傳的最大位元組數,如果是多檔案上傳的話,表示的總檔案的大小 -->
<property name="maxUploadSize" value="80000000"/>
<!-- 檔案預設的編碼 -->
<property name="defaultEncoding" value="UTF-8"/>
</bean>
<!-- 異常處理,當上傳的檔案超過multipartResolver中maxUploadSize的大小時,會丟擲異常,並由這個處理器處理,返貨到error_load頁面 -->
<bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="org.springframework.web.multipart.MaxUploadSizeExceededException">error_load</prop>
</props>
</property>
</bean>
二、檔案下載
1、配置一個BeanNameViewResolver,將邏輯檢視名字解析為bean的Name屬性,從而根據name屬性,找定義View的bean
這種方式需要在控制Controller中返回一個bean的id或name,然後BeanNameViewResolver會根據根據id找到對應的bean解析 配置檔案: <!-- 檢視解析器,將邏輯檢視名字解析為bean的Name屬性,從而根據name屬性,找定義View的bean-->
<bean class="org.springframework.web.servlet.view.BeanNameViewResolver">
<property name="order" value="1"/>
</bean>
其中,order表示viewResolver的優先順序,order的值越小,優先順序越高。根據優先順序來決定呼叫哪個解析器。
Controller控制器程式碼:
/**
* 方法一:返回一個bean的Id,利用BeanNameViewResolver解析
*
* @param modelMap
* @param srcPath
* @param fileName
* @param fileType
* @param request
* @param response
* @return
* @throws Exception
*/
@RequestMapping(value = "/download1")
public String download1(ModelMap modelMap,
@RequestParam("path") String srcPath,
@RequestParam("fileName") String fileName,
@RequestParam("fileType") String fileType,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
fileName = URLDecoder.decode(fileName, "UTF-8");
logger.info("**********************************開始下載檔案********************************");
logger.info("**********************************下載請求path:" + srcPath+ "********************************");
logger.info("**********************************下載請求fileName:" + fileName + "********************************");
logger.info("**********************************下載請求fileType:" + fileType + "********************************");
modelMap.put("path", srcPath);
modelMap.put("fileName", fileName);
modelMap.put("fileType", fileType);
return "fileDownLoad";
}
配置檔案中必須要有id或name=fileDownLoad的bean fileDownLoad的View
public class FileDownLoad extends AbstractView {
@Override
protected void renderMergedOutputModel(Map<String, Object> map,
HttpServletRequest request, HttpServletResponse response) {
OutputStream output = null;
FileInputStream fileIn = null;
String path = (String) map.get("path");
String fileName = (String) map.get("fileName");
String fileType = (String) map.get("fileType");
try {
response.setContentType(fileType + ";charset=UTF-8");
output = response.getOutputStream();
if (path == null || "".equals(path)) {
output.write("檔案不存在".getBytes());
} else {
File file = new File(path + File.separator + fileName);
// 當檔名中有中文時,會出現亂碼,通過new
// String(fileName.getBytes("utf-8"),"ISO8859-1")轉換
response.setHeader(
"Content-Disposition",
"attachment;filename="
+ new String(fileName.getBytes("utf-8"),
"ISO8859-1"));
fileIn = new FileInputStream(file);
int i = 0;
byte[] buffer = new byte[1024];
while ((i = fileIn.read(buffer)) != -1) {
output.write(i);
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fileIn != null) {
try {
fileIn.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (output != null) {
try {
output.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
2.利用ResponseEntity<byte[]>
/**
* 方法二:利用ResponseEntity<byte[]>
*
* @param srcPath
* @param fileName
* @param fileType
* @return
* @throws Exception
*/
@RequestMapping(value = "/download2")
public ResponseEntity<byte[]> download2(
@RequestParam("path") String srcPath,
@RequestParam("fileName") String fileName,
@RequestParam("fileType") String fileType) throws Exception {
fileName = URLDecoder.decode(fileName, "UTF-8");
logger.info("**********************************開始下載檔案********************************");
logger.info("**********************************下載請求path:" + srcPath+ "********************************");
logger.info("**********************************下載請求fileName:"+ fileName + "********************************");
logger.info("**********************************下載請求fileType:"+ fileType + "********************************");
File file = new File(srcPath + File.separator + fileName);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
// 當檔名中有中文時,會出現亂碼,通過new String(fileName.getBytes("utf-8"),"ISO8859-1")轉換
headers.setContentDispositionFormData("attchement",
new String(fileName.getBytes("UTF-8"), "ISO-8859-1"));
return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),
headers, HttpStatus.CREATED);
}
applicationContext.xml檔案的完整配置:
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
<!-- <context:component-scan base-package="com.xliang.mvc"/>
<mvc:annotation-driven/> -->
<!-- spring mvc 3.1之後基於註解的處理器對映器HandlerMapping -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
<!-- spring mvc 3.1之後基於註解的處理器介面卡HandlerAdapter -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/>
<!-- 在spring mvc 3.1的RequestMappingHandlerAdapter中messageConverters屬性預設值是分別是:
ByteArrayHttpMessageConverter,StringHttpMessageConverter,
SourceHttpMessageConverter,AllEncompassingFormHttpMessageConverter
如果這裡指定了其他的轉換器,則不會載入預設的轉換器。在使用ResponseEntity來下載檔案的時候,如果使用了其他的非預設的轉換器,
則必須加上ByteArrayHttpMessageConverter,如下: -->
<!--
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<property name="messageConverters">
<list>
<bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"/>
</list>
</property>
</bean>
-->
<!-- 控制器 -->
<bean id="fileUpAndDownloadController" class="com.xliang.mvc.controller.FileUpAndDownloadController"/>
<bean id="fileDownloadController" class="com.xliang.mvc.controller.FileDownloadController"/>
<!-- 檔案上傳解析器 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 允許檔案上傳的最大位元組數,如果是多檔案上傳的話,表示的總檔案的大小 -->
<property name="maxUploadSize" value="80000000"/>
<!-- 檔案預設的編碼 -->
<property name="defaultEncoding" value="UTF-8"/>
</bean>
<!-- 異常處理,當上傳的檔案超過multipartResolver中maxUploadSize的大小時,會丟擲異常,並由這個處理器處理,返貨到error_load頁面 -->
<bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="org.springframework.web.multipart.MaxUploadSizeExceededException">error_load</prop>
</props>
</property>
</bean>
<!-- 檢視解析器,將邏輯檢視名字解析為一個路徑 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
<property name="order" value="2"/>
</bean>
<!-- 檢視解析器,將邏輯檢視名字解析為bean的Name屬性,從而根據name屬性,找定義View的bean-->
<bean class="org.springframework.web.servlet.view.BeanNameViewResolver">
<property name="order" value="1"/>
</bean>
<!-- 繼承AbstractView的bean BeanNameViewResolver會根據Controller中返回的-->
<bean id="fileDownLoad" class="com.xliang.mvc.view.FileDownLoad"/>
</beans>
web.xml檔案的完整配置:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0">
<display-name>springMVCDemo02</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<filter>
<filter-name>CharacterEncoding</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>CharacterEncoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>FileUpload</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:conf/applicationContext.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>FileUpload</servlet-name>
<url-pattern>*.html</url-pattern>
</servlet-mapping>
</web-app>
完整程式碼請點選這裡下載