原文地址：http://blog.csdn.net/java_cxrs/article/details/6004144
描述：
通过struts2实现多图片上传。
我使用的版本是2.2.1，使用的包有如下几个：
具体实现：
1.创建上传图片的页面
fileUpload.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'fileUpLoad.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css">
-->
</head>
<body>
<center>
<s:form action ="fileUpload" method ="POST" enctype ="multipart/form-data" >
<s:fielderror />
<s:file name ="myFile" label ="Image File1"/>
<s:file name ="myFile" label ="Image File2"/>
<s:file name ="myFile" label ="Image File3"/>
<s:textfield name ="caption" label ="Caption" />
<s:submit/>
</s:form>
</center>
</body>
</html>
在FileUpload.jsp中，先将表单的提交方式设为POST，然后将enctype设为multipart/form-data，这并没有什么特别之处。接下来，<s:file/>标志将文件上传控件绑定到Action的myFile属性，因为要上传多张图片我们就暂且添加三个file
注意这三个file的name属性要相同。
2.创建处理图片上传的action
FileUploadAction.java
package com.ywjava.action; import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.List; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; public class FileUploadAction extends ActionSupport {
private static final long serialVersionUID = 572146812454l;
private static final int BUFFER_SIZE = 16 * 1024;
private List<File> myFile = new ArrayList<File>();
private List<String> contentType = new ArrayList<String>();
private List<String> fileName = new ArrayList<String>(); //文件名
private List<String> imageFileName = new ArrayList<String>();
private String caption; private static void copy(File src, File dst) {
try {
InputStream in = null;
OutputStream out = null;
try {
in = new BufferedInputStream(new FileInputStream(src),
BUFFER_SIZE);
out = new BufferedOutputStream(new FileOutputStream(dst),
BUFFER_SIZE);
byte[] buffer = new byte[BUFFER_SIZE];
while (in.read(buffer) > 0) {
out.write(buffer);
}
} finally {
if (null != in) {
in.close();
}
if (null != out) {
out.close();
}
}
} catch (Exception e) {
e.printStackTrace();
}
} private static String getExtention(String fileName) {
int pos = fileName.lastIndexOf(".");
return fileName.substring(pos);
} @Override
public String execute() {
if (myFile == null)
return INPUT;
for (int i = 0; i < myFile.size(); i++) {
imageFileName.add(new Date().getTime()+ getExtention(this.getMyFileFileName().get(i))) ;
File imageFile = new File(ServletActionContext.getServletContext() //得到图片保存的位置(根据root来得到图片保存的路径在tomcat下的该工程里) .getRealPath("UploadImages")
+ "/" + imageFileName);
copy(myFile.get(i), imageFile); //把图片写入到上面设置的路径里 }
return SUCCESS;
} public List<File> getMyFile() {
return myFile;
} public void setMyFile(List<File> myFile) {
this.myFile = myFile;
} public List<String> getContentType() {
return contentType;
} public void setContentType(List<String> contentType) {
this.contentType = contentType;
} public List<String> getMyFileFileName() {
return fileName;
} public void setMyFileFileName(List<String> fileName) {
this.fileName = fileName;
} public List<String> getImageFileName() {
return imageFileName;
} public void setImageFileName(List<String> imageFileName) {
this.imageFileName = imageFileName;
} public String getCaption() {
return caption;
} public void setCaption(String caption) {
this.caption = caption;
} public static int getBufferSize() {
return BUFFER_SIZE;
} }
在FileUploadAction中我分别写了setMyFileContentType、setMyFileFileName、setMyFile和setCaption四个Setter方法，
后两者很容易明白，分别对应FileUpload.jsp中的<s:file/>和<s:textfield/>标志。但是前两者并没有显式地与任何的页面标志绑定，
那么它们的值又是从何而来的呢？其实，<s:file/>标志不仅仅是绑定到myFile，
还有myFileContentType（上传文件的MIME类型）和myFileFileName（上传文件的文件名，该文件名不包括文件的路径）。
因此，<s:file name="xxx" />对应Action类里面的xxx、xxxContentType和xxxFileName三个属性。
FileUploadAction作用是将浏览器上传的文件拷贝到WEB应用程序的
UploadImages文件夹下，新文件的名称是由系统时间与上传文件的后缀组成，
该名称将被赋给imageFileName属性，以便上传成功的跳转页面使用。
3.创建显示图片的页面
showUpload.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>"> <title>Show Image</title> <meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css">
--> </head> <body>
<s:iterator value="imageFileName" status="length"> <div
style="padding: 3px; border: solid 1px #cccccc; text-align: center">
<img src='UploadImages/<s:property value ="imageFileName" /> ' />
<br />
<s:property value="caption" />
</div>
</s:iterator>
<s:property value ="caption" /> </body>
</html>
4.Action配置文件
Struts.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd"> <struts> <constant name="struts.enable.DynamicMethodInvocation" value="false" />
<constant name="struts.devMode" value="false" /> <!-- 指定国际化资源文件的baseName为messageResource -->
<constant name="struts.custom.i18n.resources" value="messageResource" /> <!-- 设置该应用使用的解码集 -->
<constant name="struts.i18n.encoding" value="utf-8" /> <!-- 上传的全部图片的最大限制-->
<constant name="struts.multipart.maxSize" value="1024102400" /> <!-- 临时存放文件的路径 -->
<constant name="struts.multipart.saveDir" value="d:/test" /> <package name="index" namespace="/" extends="struts-default"> <action name="index" class="com.ywjava.action.IndexAction">
<result>
/WEB-INF/page/fileUpLoad.jsp
</result>
</action> <action name="fileUpload" class="com.ywjava.action.FileUploadAction">
<!-- 限制图片的格式和图片的大小 -->
<interceptor-ref name="fileUpload">
<param name="allowedTypes">
image/bmp,image/png,image/gif,image/jpeg,image/pjpeg
</param>
</interceptor-ref>
<!-- 默认的拦截器，必须要写 -->
<interceptor-ref name="defaultStack" />
<result name="input"> /WEB-INF/page/fileUpLoad.jsp</result>
<result name="success">/WEB-INF/page/showUpload.jsp</result> </action>
</package>
<!--
<constant name="struts.multipart.saveDir" value="d:/test"></constant>
--> <!-- Add packages here --> </struts>
Action配置文件里所做的配置都有注释，不明白的地方看下注释
另外因为做了国际化处理所以需要一个国际化配置的文件
放在src目录下
5.国际化配置文件
messageResource_zh_CN.properties(只配置了中文的)
struts.messages.error.content.type.not.allowed=/u4E0A/u4F20/u7C7B/u578B/u9519/u8BEF
struts.messages.error.file.too.large=/u4E0A/u4F20/u6587/u4EF6/u592A/u5927
总结：struts2上传图片利用了fileUpload拦截器而变的简单，主要是在action中做相应处理获取文件的相应信息。