Java程式教學甘仔店: [JAVA_Spring]建立一個Spring MVC fileupload project

2013年5月5日星期日

[JAVA_Spring]建立一個Spring MVC fileupload project

本文使用 Spring Web model-view-controller (MVC) framework
建立一個簡單的一個檔案上傳程式

1、本文中使用的相關技術

Eclipse 4.2 Version: Juno Service Release 2
Maven 3.0.5
JAVA JDK 1.6.0_24
Spring 3.2.2.RELEASE。

P.S Spring 3.x, 需 JDK 1.5 以上。

2、建立一個Maven專案

P.S 請參考前一篇文章建立一個基本簡單的Spring MVC project

3、加入 Spring 3.0 jar
加入在Maven專案中的pom.xml

程式碼：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.sample</groupId>
<artifactId>SpringMVC_File_Upload_sample</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>SpringMVC_File_Upload_sample Maven Webapp</name>
<url>http://maven.apache.org</url>

<build>
<finalName>SpringMVC_File_Upload_sample</finalName>
</build>

<properties>
<spring.version>3.2.2.RELEASE</spring.version>
</properties>

<dependencies>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>

<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3</version>
</dependency>

</dependencies>

</project>

4. 建立JSP 頁面
目錄 : src/main/webapp/
檔名 : index.jsp

<jsp:forward page="show.html"></jsp:forward>

目錄 : src/main/webapp/WEB-INF/jsp
檔名 : file_upload_form.jsp

程式碼：

<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<html>
<head>
<title>Spring MVC Multiple File Upload</title>
</head>
<body>
<h1>Spring Multiple File Upload example</h1>

<form:form method="post" action="save.html"
modelAttribute="uploadForm" enctype="multipart/form-data">

<p>please select file </p>
<table>
<tr>
<td><input name="files[0]" type="file" /></td>
</tr>
</table>
<br/><input type="submit" value="Upload" />
</form:form>
</body>
</html>

目錄 : src/main/webapp/WEB-INF/jsp
檔名 : file_upload_success.jsp

程式碼：

<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<html>
<head>
<title>Spring MVC Multiple File Upload</title>
</head>
<body>
<h1>Spring Multiple File Upload example</h1>
<p>Following files are uploaded successfully.</p>
<ol>
<c:forEach items="${files}" var="file">
<li>${file}</li>
</c:forEach>
</ol>
</body>
</html>

5. 加入spring設定到Web application web.xml

檔名 : web.xml
程式碼：

<web-app
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">

<display-name>Archetype Created Web Application</display-name>

<servlet>
<servlet-name>spring</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
<servlet-name>spring</servlet-name>
<url-pattern>*.html</url-pattern>
</servlet-mapping>

</web-app>

6. 建立 Spring mvc Config xml 檔

檔名: spring-servlet.xml

程式碼：

<?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:mvc="http://www.springframework.org/schema/mvc"

xsi:schemaLocation="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.xsd

http://www.springframework.org/schema/mvc

http://www.springframework.org/schema/mvc/spring-mvc.xsd">

<context:annotation-config />

<context:component-scan base-package="com.springmvc.fileupload.sample.controller"/>

<bean id="multipartResolver"

class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>

<bean id="jspViewResolver"

class="org.springframework.web.servlet.view.InternalResourceViewResolver">

<property name="viewClass"

value="org.springframework.web.servlet.view.JstlView" />

</bean>

</beans>

7. 建立可
以暫時存放檔案的資料型態

如：
目錄 : src/main/java/com/springmvc/fileupload/sample/form
檔名 : FileUploadForm.java
程式碼：

package com.springmvc.fileupload.sample.form;

import java.util.List;

import org.springframework.web.multipart.MultipartFile;

public class FileUploadForm {

 private List files;

 public List getFiles() {
  return files;
 }

 public void setFiles(List files) {
  this.files = files;
 }
}

8. 建立Controller & Mapping
在Spring 3 裡大量使用 annotation 。

如：
@Controller
目錄 : src/main/java/com/springmvc/fileupload/sample/controller
檔名 : FileUploadController.java
程式碼：

package com.springmvc.fileupload.sample.controller;

import java.util.ArrayList;
import java.util.List;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MultipartFile;

import com.springmvc.fileupload.sample.form.FileUploadForm;

@Controller
public class FileUploadController {

 @RequestMapping(value = "/show", method = RequestMethod.GET)
 public String displayForm() {
  return "file_upload_form";
 }
 
 @RequestMapping(value = "/save", method = RequestMethod.POST)
 public String save(
   @ModelAttribute("uploadForm") FileUploadForm uploadForm,
     Model map) {
  
  List files = uploadForm.getFiles();

  List fileNames = new ArrayList();
  
  if( files != null && files.size() > 0 ) {
   for (MultipartFile multipartFile : files) {
    String fileName = multipartFile.getOriginalFilename();
    fileNames.add(fileName);
   }
  }
  
  map.addAttribute("files", fileNames);
  return "file_upload_success";
 }
}