一、應用服務器功能
- 應用服務器提供與用戶交互,響應客戶的請求。下列代碼提供三種文件上傳形式,第一種controller的代碼塊是使用不了的,因爲spingmvc自身的文件解析器,將解析後的文件傳給controller,第一種controller代碼塊又來解析一遍,會得到空字符串。本例主要分析跨服務器上傳的功能。
- 跨服務器需要使用的jar包需導入如下座標:
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-core</artifactId>
<version>1.18.1</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-client</artifactId>
<version>1.18.1</version>
下列是spingmvc區別於普通文件上傳的過程。
代碼如下:
1. web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Archetype Created Web Application</display-name>
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!--配置解決中文亂碼的過濾器-->
<filter>
<filter-name>characterEncodingFilter</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>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
2. springmvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 開啓註解掃描 -->
<context:component-scan base-package="cn.itcast"/>
<!-- 視圖解析器對象 -->
<bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--前端控制器,哪些靜態資源不攔截-->
<mvc:resources location="/css/" mapping="/css/**"/>
<mvc:resources location="/images/" mapping="/images/**"/>
<mvc:resources location="/js/" mapping="/js/**"/>
<!--配置文件解析器對象-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="10485760" />
</bean>
<!-- 開啓SpringMVC框架註解的支持 -->
<mvc:annotation-driven />
</beans>
3. html
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h3>傳統文件上傳</h3>
<form action="/fileupload" method="post" enctype="multipart/form-data">
選擇文件:<input type="file" name="upload" /><br/>
<input type="submit" value="上傳" />
</form>
<h3>Springmvc文件上傳</h3>
<form action="/fileupload2" method="post" enctype="multipart/form-data">
選擇文件:<input type="file" name="upload" /><br/>
<input type="submit" value="上傳" />
</form>
<h3>跨服務器文件上傳</h3>
<form action="/fileupload3" method="post" enctype="multipart/form-data">
選擇文件:<input type="file" name="upload" /><br/>
<input type="submit" value="上傳" />
</form>
</body>
</html>
4. Controller層
- 在跨服務器文件傳輸的過程代碼塊,我們需要定義文件服務器的地址和接收文件的文件夾,此處我們定義的端口爲:80文件夾爲:uploads,所以我的地址爲http://localhost:80/uploads/ 因爲後面在代碼種仍然需要加文件名,所以在uploads後面需加‘/’。我們需要注意文件服務器的端口號要必須和我們的url保持一致,而且需要在文件服務器的target中建立對應的uploads文件夾。
package top.san.controllerr;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.WebResource;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.util.List;
import java.util.UUID;
@org.springframework.stereotype.Controller
//@RequestMapping("/")
public class Controller {
/**
* wjsc
*/
@PostMapping("/fileupload")
public String fileupload(HttpServletRequest request) throws Exception {
System.out.println("文件上傳");
// 使用fileupload組件完成文件上傳
// 上傳的位置
String path = request.getSession().getServletContext().getRealPath("/uploads/");
// 判斷,該路徑是否存在
File file = new File(path);
if(!file.exists()){
// 創建該文件夾
file.mkdirs();
}
// 解析request對象,獲取上傳文件項
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
// 解析request
List<FileItem> items = upload.parseRequest(request);
// 遍歷
for(FileItem item:items){
// 進行判斷,當前item對象是否是上傳文件項
if(item.isFormField()){
// 說明普通表單向
System.out.println("判斷爲表單項");
}else{
// 說明上傳文件項
// 獲取上傳文件的名稱
String filename = item.getName();
// // 把文件的名稱設置唯一值,uuid
String uuid = UUID.randomUUID().toString().replace("-", "");
filename = uuid+"_"+filename;
// 完成文件上傳
item.write(new File(path,filename));
System.out.println("上傳完了");
// 刪除臨時文件,大小大於10kB就會有緩存
item.delete();
}
}
return "success";
}
/**
* SpringMVC文件上傳
* @return
*/
@RequestMapping("/fileupload2")
public String fileuoload2(HttpServletRequest request, MultipartFile upload) throws Exception {
System.out.println("springmvc文件上傳...");
// 使用fileupload組件完成文件上傳
// 上傳的位置
String path = request.getSession().getServletContext().getRealPath("/uploads/");
// 判斷,該路徑是否存在
File file = new File(path);
if(!file.exists()){
// 創建該文件夾
file.mkdirs();
}
// 說明上傳文件項
// 獲取上傳文件的名稱
String filename = upload.getOriginalFilename();
// 把文件的名稱設置唯一值,uuid
String uuid = UUID.randomUUID().toString().replace("-", "");
filename = uuid+"_"+filename;
// 完成文件上傳
upload.transferTo(new File(path,filename));
return "success";
}
/**
* 跨服務器文件上傳
* @return
*/
@PostMapping("/fileupload3")
public String fileuoload3(MultipartFile upload) throws Exception {
System.out.println("跨服務器文件上傳...");
// 定義上傳文件服務器路徑
String path = "http://localhost:80/uploads/";
// 說明上傳文件項
// 獲取上傳文件的名稱
String filename = upload.getOriginalFilename();
// 把文件的名稱設置唯一值,uuid
String uuid = UUID.randomUUID().toString().replace("-", "");
filename = uuid+"_"+filename;
// 創建客戶端的對象
Client client = Client.create();
// 和圖片服務器進行連接
WebResource webResource = client.resource(path + filename);
// 上傳文件
webResource.put(upload.getBytes());
return "success";
}
}
二、文件服務器
文件服務器只需要建立一個web服務器,不需要其他代碼,但可能會出現404、405、409的錯誤返回,需要確認uploads文件夾的創建,若是出現405需將web.xml改成如下。
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Archetype Created Web Application</display-name>
<servlet>
<servlet-name>default</servlet-name>
<servlet-class>org.apache.catalina.servlets.DefaultServlet</servlet-class>
<init-param>
<param-name>debug</param-name>
<param-value>0</param-value>
</init-param>
<init-param>
<param-name>readonly</param-name>
<param-value>false</param-value>
</init-param>
<init-param>
<param-name>listings</param-name>
<param-value>false</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
</web-app>