一、前言
由於Struts2框架對上傳組件進行了封裝，使得文件上傳的實現簡單。
在Struts2框架中提供對commons-fileupload組件的支持，並且默認使用該組件實現文件上傳。因此，為了實現文件上傳功能，我們需要在項目中包含如下兩個jar文件：
commons-fileupload-x.x.x.jar、commons-io-x.x.x.jar 注意：jar文件版本取決於當前工程使用的Struts2的版本。
二、實現文件上傳
1）上傳頁面的准備
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@taglib uri="/struts-tags" prefix="s"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>文件上傳</title>
</head>
<body>
<s:form action="upload" enctype="multipart/form-data" method="post">
<s:textfield name="title" label="標題"/>
<s:file name="upload" label="選擇文件"/>
<s:submit name="submit" value="文件上傳"/>
</s:form>
</body>
</html>
2）開發實現文件上傳的Action
package cn.happy.action;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionSupport;
@SuppressWarnings("serial")
public class UploadAction extends ActionSupport implements Action{
//封裝上傳文件屬性
private String upload;
//封裝上傳文件的類型
private String uploadContentType;
//封裝上傳文件的名稱
private String uploadFileName;
//獲取文件上傳路徑
private String savePath;
@Override
public String execute() throws Exception{
byte[] buffer=new byte[1024];
//讀取文件
FileInputStream fis=new FileInputStream(getUpload());
//保存文件，並設置保存目錄的路徑
FileOutputStream fos=new FileOutputStream(getSavePath()+"\\"+this.getUploadFileName());
int length=fis.read(buffer);
while(length>0){
//每次寫入長度的內容
fos.write(buffer,0,length);
length=fis.read(buffer);
}
fis.close();
fos.flush();
fos.close();
return SUCCESS;
}
//獲取上傳文件的保存路徑
//通過讀取存放目錄獲取的保存路徑
public String getSavePath() {
return ServletActionContext.getServletContext().getRealPath(savePath);
}
public void setSavePath(String savePath) {
this.savePath = savePath;
}
public String getUpload() {
return upload;
}
public void setUpload(String upload) {
this.upload = upload;
}
public String getUploadContentType() {
return uploadContentType;
}
public void setUploadContentType(String uploadContentType) {
this.uploadContentType = uploadContentType;
}
public String getUploadFileName() {
return uploadFileName;
}
public void setUploadFileName(String uploadFileName) {
this.uploadFileName = uploadFileName;
}
}
3）Struts.xml配置
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">
<struts >
<!-- <constant name="struts.devMode" value="true" /> -->
<constant name="struts.devMode" value="false" />
<!--創建一個default包，繼承自Struts2的struts-default包 -->
<package name="default" namespace="" extends="struts-default">
<action name="upload" class="cn.happy.action.UploadAction">
<!-- 通過param參數設置保存目錄路徑 -->
<param name="savePath">/upload</param>
<result name="success">upload_success.jsp</result>
</action>
</package>
</struts>
4）在成功頁面
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@taglib uri="/struts-tags" prefix="s"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>文件上傳成功</title>
</head>
<body>
您所上傳的文件是：<s:property value="uploadFileName"/>
文件類型：<s:property value="uploadContentType"/>
文件路徑：<s:property value="savePath"/>
</body>
</html>
三、實現文件下載
1）下載頁面准備
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@taglib uri="/struts-tags" prefix="s"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>文件下載</title>
</head>
<body>
<a href="download?fileName=007.jpg">點擊此處下載文檔</a>
</body>
</html>
2）開始實現文件下載的Action
package cn.happy.action;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
@SuppressWarnings("serial")
public class FileDownAction extends ActionSupport {
//讀取下載的文件目錄
private String inputPath;
//下載文件的文件名
private String fileName;
//讀取下載文件的輸入流
@SuppressWarnings("unused")
private InputStream inputStream;
//下載的文件類型
private String conetntType;
//創建inputStream輸入流
@Override
public String execute() throws Exception {
return SUCCESS;
}
public InputStream getInputStream() throws FileNotFoundException {
String path=ServletActionContext.getServletContext().getRealPath(inputPath);
return new BufferedInputStream(new FileInputStream(path+"\\"+fileName));
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}
public String getInputPath() {
return inputPath;
}
public void setInputPath(String inputPath) {
this.inputPath = inputPath;
}
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
public String getConetntType() {
return conetntType;
}
public void setConetntType(String conetntType) {
this.conetntType = conetntType;
}
}
3）Struts.xml配置
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">
<struts >
<!-- <constant name="struts.devMode" value="true" /> -->
<constant name="struts.devMode" value="false" />
<!--創建一個default包，繼承自Struts2的struts-default包 -->
<package name="default" namespace="" extends="struts-default">
<action name="upload" class="cn.happy.action.UploadAction">
<!-- 文件下載 -->
<action name="download" class="cn.happy.action.FileDownAction">
<param name="inputPath">/upload</param>
<result name="success" type="stream">
<param name="conetntType">application/octet-stream</param>
<!-- <param name="conetntType">image/gif</param> -->
<param name="inputName">inputStream</param>
<param name="contentDisposition">attachement;filename="${fileName}"</param>
<param name="bufferSize">4096</param>
</result>
</action>
</package>
</struts>
注意！！！！
contentType對應的文件類型
文件類型 contentType設置 Word application/msword Execl Application/vnd.ms-excel PPT Application/vnd.ms-powerpoint 圖片 image/gif、image/bmp、image/jpeg 文本文件 text/plain HTML網頁 text/html 可執行文件 application/octet-stream
