檔案上傳和下載(二)--【struts2】
阿新 • • 發佈：2019-02-15
一、簡介
struts2在原有的上傳解析器繼承上做了進一步封裝，更進一步簡化了檔案上傳。
struts2預設使用的是Jakarta和Common-FileUpload的檔案上傳框架，因此，如果需要使用struts2的檔案上傳功能，則需要在web應用匯入相關jar包。
二、實現原理
1、Action需要使用3個屬性來封裝該檔案域的資訊：
（1）型別為File的xxx屬性封裝了該檔案域對應的檔案內容。
（2）型別為String的xxxFileName屬性封裝了改檔案域對應的檔案的檔案型別。
（3）型別為String的xxxContentType屬性封裝了該檔案域對應的檔案的型別。
2、配置struts.xml
struts.xml配置攔截器，設定允許上傳型別、檔案大小等資訊。
3、官網例子
三、專案實踐【myeclipse10】
專案目錄預覽
web.xml配置
<?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" 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"> <display-name>struts2</display-name> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
上傳action【Struts2UploadAction.java】
package com.wuhn.struts2.action; import java.io.File; import java.io.IOException; import org.apache.commons.io.FileUtils; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; /** * @author wuhn * @建立時間 2015-12-09 * @功能 上傳 * **/ public class Struts2UploadAction extends ActionSupport { private File image; //上傳的檔案 private String imageFileName; //檔名稱 要注意字首要和file的變數一樣 private String imageContentType; //檔案型別 要注意字首要和file的變數一樣 private String result;//返回資訊 public File getImage() { return image; } public void setImage(File image) { this.image = image; } public String getImageFileName() { return imageFileName; } public void setImageFileName(String imageFileName) { this.imageFileName = imageFileName; } public String getImageContentType() { return imageContentType; } public void setImageContentType(String imageContentType) { this.imageContentType = imageContentType; } public String getResult() { return result; } public void setResult(String result) { this.result = result; } @Override public String execute() throws Exception{ //設定儲存路徑 String path = ServletActionContext.getServletContext().getRealPath("/images"); File localFile = new File(path); if(!localFile.exists()){ localFile.mkdir(); } System.out.println("image:"+image); System.out.println("imageFileName:"+imageFileName); System.out.println("imageContentType:"+imageContentType); System.out.println("檔案是否存在："+image.exists()); //儲存檔案 FileUtils.copyFile(image, new File(localFile, imageFileName)); result = "上傳成功！"; return SUCCESS; } }
下載action【Struts2DownloadAction.java】
package com.wuhn.struts2.action;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import org.apache.commons.io.FileUtils;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
/**
* @author wuhn
* @建立時間 2015-12-09
* @功能 下載
* **/
public class Struts2DownloadAction extends ActionSupport{
private String inputPath;//下載路徑 在struts.xml中配置
private String filename;//下載檔名
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;
}
@Override
public String execute() throws Exception {
return SUCCESS;
}
public InputStream getInputStream() throws IOException{
String path = ServletActionContext.getServletContext().getRealPath("/images");
String filepath = path + "\\" +filename;
File file = new File(filepath);
return FileUtils.openInputStream(file);
//return ServletActionContext.getServletContext().getResourceAsStream(inputPath);
}
public String getDownloadFileName(){
String downloadFileName = "";
//中文處理
try {
downloadFileName = URLEncoder.encode(filename, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return downloadFileName;
}
}
批量上傳【BatchStruts2UploadAction.java】
package com.wuhn.struts2.action;
import java.io.File;
import java.util.List;
import org.apache.commons.io.FileUtils;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
/**
* @author wuhn
* @建立時間 2015-12-10
* @功能 批量上傳
* **/
public class BatchStruts2UploadAction extends ActionSupport {
private List<File> image; //上傳的檔案
private List<String> imageFileName; //檔名稱 要注意字首要和file的變數一樣
private List<String> imageContentType; //檔案型別 要注意字首要和file的變數一樣
private String result;//返回資訊
public List<File> getImage() {
return image;
}
public void setImage(List<File> image) {
this.image = image;
}
public List<String> getImageFileName() {
return imageFileName;
}
public void setImageFileName(List<String> imageFileName) {
this.imageFileName = imageFileName;
}
public List<String> getImageContentType() {
return imageContentType;
}
public void setImageContentType(List<String> imageContentType) {
this.imageContentType = imageContentType;
}
public String getResult() {
return result;
}
public void setResult(String result) {
this.result = result;
}
@Override
public String execute() throws Exception{
//設定儲存路徑
String path = ServletActionContext.getServletContext().getRealPath("/images");
File localFile = new File(path);
if(!localFile.exists()){
localFile.mkdir();
}
//迴圈儲存檔案
for (int i=0;i<image.size();i++) {
FileUtils.copyFile(image.get(i), new File(localFile, imageFileName.get(i)));
}
result = "上傳成功！";
return SUCCESS;
}
}
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.enable.DynamicMethodInvocation" value="false" />
<constant name="struts.devMode" value="true" />
<!-- 該屬性指定需要Struts2處理的請求字尾，該屬性的預設值是action，即所有匹配*.action的請求都由Struts2處理。
如果使用者需要指定多個請求字尾，則多個字尾之間以英文逗號（,）隔開。 -->
<constant name="struts.action.extension" value="action" />
<!-- 設定瀏覽器是否快取靜態內容,預設值為true(生產環境下使用),開發階段最好關閉 -->
<constant name="struts.serve.static.browserCache" value="false" />
<!-- 當struts的配置檔案修改後,系統是否自動重新載入該檔案,預設值為false(生產環境下使用),開發階段最好開啟 -->
<constant name="struts.configuration.xml.reload" value="true" />
<!-- 開發模式下使用,這樣可以打印出更詳細的錯誤資訊 -->
<constant name="struts.devMode" value="true" />
<!-- 預設的檢視主題 -->
<constant name="struts.ui.theme" value="simple" />
<!--<constant name="struts.objectFactory" value="spring" />-->
<!--解決亂碼 -->
<constant name="struts.i18n.encoding" value="UTF-8" />
<!-- 指定允許上傳的檔案最大位元組數。預設值是2097152(2M) -->
<constant name="struts.multipart.maxSize" value="10701096"/>
<!-- 設定上傳檔案的臨時資料夾,預設使用javax.servlet.context.tempdir
<constant name="struts.multipart.saveDir " value="d:/tmp" />
-->
<!-- 國際化 app_zh_CN.properties -->
<constant name="struts.custom.i18n.resources" value="app"></constant>
<package name="default" namespace="/" extends="struts-default">
<!-- 上傳 -->
<action name="upload" class="com.wuhn.struts2.action.Struts2UploadAction">
<result name="success">/jsp/01.jsp</result>
<result name="input">/jsp/error.jsp</result>
<!-- 配置攔截器限制上傳檔案型別及大小 -->
<interceptor-ref name="fileUpload">
<!-- 檔案過濾 -->
<param name="allowedTypes">image/png,image/gif,image/jpeg</param>
<!-- 檔案大小, 以位元組為單位 -->
<param name="maximumSize">10240000</param>
</interceptor-ref>
<!-- 預設攔截器必須放在fileUpload之後，否則無效 -->
<interceptor-ref name="defaultStack"></interceptor-ref>
</action>
<!-- 批量上傳 -->
<action name="batchUpload" class="com.wuhn.struts2.action.BatchStruts2UploadAction">
<result name="success">/jsp/03.jsp</result>
<result name="input">/jsp/error.jsp</result>
<!-- 配置攔截器限制上傳檔案型別及大小 -->
<interceptor-ref name="fileUpload">
<!-- 檔案過濾 -->
<param name="allowedTypes">image/png,image/gif,image/jpeg</param>
<!-- 檔案大小, 以位元組為單位 -->
<param name="maximumSize">10240000</param>
</interceptor-ref>
<!-- 預設攔截器必須放在fileUpload之後，否則無效 -->
<interceptor-ref name="defaultStack"></interceptor-ref>
</action>
<!-- 下載 -->
<action name="download" class="com.wuhn.struts2.action.Struts2DownloadAction">
<!-- <param name="inputPath">images/20151026165425.png</param> -->
<result name="success" type="stream">
<param name="contentType">application/octet-stream</param>
<param name="inputName">inputStream</param>
<param name="contentDisposition">attachment;filename="${downloadFileName}"</param>
<param name="bufferSize">1024</param>
</result>
</action>
</package>
<!--
<include file="example.xml"/>
-->
</struts>
頁面
1、上傳頁面
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@taglib uri="/struts-tags" prefix="s" %>
<!DOCTYPE>
<html>
<head>
<base href="<%=basePath%>">
<title>上傳</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1.,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<form action="<%=path%>/upload.action" method="post" enctype="multipart/form-data">
上傳檔案：<input type="file" name="image"/>
<input type="submit" value="提交"/>${result}
</form>
</body>
</html>
2、下載頁面
<%@ 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>
<head>
<base href="<%=basePath%>">
<title>下載</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">
-->
</head>
<body>
下載檔案<a href="<%=path%>/download.action?filename=20151026165425.png">檔案</a>
</body>
</html>
3、批量上傳
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
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>批量上傳</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">
-->
</head>
<body>
<form action="<%=path%>/batchUpload.action" method="post" enctype="multipart/form-data">
上傳檔案1：<input type="file" name="image"/>
上傳檔案2：<input type="file" name="image"/>
上傳檔案3：<input type="file" name="image"/>
<input type="submit" value="提交"/>${result}
</form>
</body>
</html>
這裡還做了一個上傳erro統一處理頁面
<%@ 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>
<head>
<base href="<%=basePath%>">
<title>My JSP 'error.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">
-->
</head>
<body>
錯誤：<s:fielderror></s:fielderror>
</body>
</html>
