<一>簡述：
Struts2的文件上傳其實也是通過攔截器來實現(xiàn)的，只是該攔截器定義為默認攔截器了，所以不用自己去手工配置，<interceptor name="fileUpload" class="org.apache.struts2.interceptor.FileUploadInterceptor"/>
<二>指定用戶上傳文件的大小，有兩種方式：
1）默認是在default.PRoperties 文件的 struts.multipart.maxSize=2097152 鍵值指定為2097152 也就是2M，通過計算 2097152/(1024*1024) = 2 M
那我們可以改變其默認值，只要在src目錄下，新建一個 struts.properties 文件，指定上傳大小 如下：
一次上傳只可以上傳10M，不管一次上傳多少個文件，按總和計算
2）在struts.xml文件中指定，如圖：
其實name就對應struts.properties的鍵，value對應 值
注意：如果即在struts.properties設定文件上傳大小，又在struts.xml 設定文件上傳大小，則struts.properties的優(yōu)先級高于struts.xml，一般在一處指定上傳大小即可，推薦 struts.properties
<三>Struts2之單文件上傳
1.fileupload.jsp
<%@ 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>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"> --> </head> <body> <!-- enctype 默認是 application/x-www-form-urlencoded --> <form action="FileUpload2" enctype="multipart/form-data" method="post" > 用戶名：<input type="text" name="usename"> <br/> 上傳文件：<input type="file" name="file1"><br/> <input type="submit" value="提交"/> </form> </body> </html> 2.具體處理上傳的 FileUpload.javapackage com.struts2.fileupload; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; /** * 單個文件上傳 * @author Administrator * 上傳文件其實是上傳了兩份， * * 首先將上傳的文件保存到 default.properties 文件中 struts.multipart.saveDir鍵指定的目錄中 * 默認是空的 * 保存在 Tomcat 6.0/work/Catalina/localhost/struts2目錄下以.tmp后綴名的文件 * * 如果要在 struts.multipart.saveDir 指定目錄， 則可以在 src文件夾下 建一個 struts.properties, * 覆蓋 default.properties 的某些鍵值 * * 還有一份是 存放在自己設定的目錄下 */ public class FileUpload extends ActionSupport { private String usename ; private File file1 ; //具體上傳文件的 引用 , 指向臨時目錄中的臨時文件 private String file1FileName ; // 上傳文件的名字 ,FileName 固定的寫法 private String file1ContentType ; //上傳文件的類型， ContentType 固定的寫法 public String getUsename() { return usename; } public void setUsename(String usename) { this.usename = usename; } public File getFile1() { return file1; } public void setFile1(File file1) { this.file1 = file1; } public String getFile1FileName() { return file1FileName; } public void setFile1FileName(String file1FileName) { this.file1FileName = file1FileName; } public String getFile1ContentType() { return file1ContentType; } public void setFile1ContentType(String file1ContentType) { this.file1ContentType = file1ContentType; } @Override public String execute() throws Exception { //獲取文件存儲路徑 String path = ServletActionContext.getRequest().getRealPath("/upload"); //輸出流 OutputStream os = new FileOutputStream(new File(path,file1FileName)); //輸入流 InputStream is = new FileInputStream(file1); byte[] buf = new byte[1024]; int length = 0 ; while(-1 != (length = is.read(buf) ) ) { os.write(buf, 0, length) ; } is.close(); os.close(); return SUCCESS; } } 3.最終顯示結果的頁面，filedemo.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 'filedemo.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> 上傳成功: <br/> usename: <s:property value="usename" /><br/> file: <s:property value="file1FileName"/><br/> contentType: <s:property value="file1ContentType"/> </body> </html> <四>Struts2之多文件上傳
1.fileupload.jsp
<%@ 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>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"> --> </head> <body> <!-- enctype 默認是 application/x-www-form-urlencoded --> <form action="FileUpload2" enctype="multipart/form-data" method="post" > 用戶名：<input type="text" name="usename"> <br/> 上傳文件：<input type="file" name="file1"><br/> 上傳文件： <input type="file" name="file1"><br/> <!-- 兩個名字相同 都是file1 --> <input type="submit" value="提交"/> </form> </body> </html> 兩個上傳文件的name屬性值要是一樣的，后臺方便處理2.具體處理上傳文件的FileUpload2.Java
多文件上傳用集合的方式
package com.struts2.fileupload; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.util.List; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; /** * 多文件上傳，用集合的方式 * @author Administrator * */ public class FileUpload2 extends ActionSupport { private String usename ; private List<File> file1 ; private List<String> file1FileName ; private List<String> file1ContentType ; public String getUsename() { return usename; } public void setUsename(String usename) { this.usename = usename; } public List<File> getFile1() { return file1; } public void setFile1(List<File> file1) { this.file1 = file1; } public List<String> getFile1FileName() { return file1FileName; } public void setFile1FileName(List<String> file1FileName) { this.file1FileName = file1FileName; } public List<String> getFile1ContentType() { return file1ContentType; } public void setFile1ContentType(List<String> file1ContentType) { this.file1ContentType = file1ContentType; } @Override public String execute() throws Exception { //獲取文件存儲路徑 String path = ServletActionContext.getRequest().getRealPath("/upload"); for(int i = 0 ; i < file1.size() ; i++ ) { OutputStream os = new FileOutputStream(new File(path,file1FileName.get(i))); InputStream is = new FileInputStream(file1.get(i)); byte[] buf = new byte[1024]; int length = 0 ; while(-1 != (length = is.read(buf) ) ) { os.write(buf, 0, length) ; } is.close(); os.close(); } return SUCCESS; } } 3.用于顯示的界面filedemo.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 'filedemo2.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> 上傳成功：<br/> usename:<s:property value="usename"/><br/> <!-- 遍歷值 --> <s:iterator value="file1FileName" id="f"> <!-- id是一個對象，目前是一個字符串集合 可任意命名 --> 文件:<s:property value="#f"/> <br/> <!-- 這里也可以調(diào)用方法 <s:property value="#f.toUpperCase()"/> --> </s:iterator> </body> </html> <三>文件下載
文件下載是一個很常見的功能，用struts2實現(xiàn)文件下載的步驟：
一）定義一個Action類，F(xiàn)ileDownload.Java
package com.struts2.filedownload; import java.io.InputStream; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; //文件下載 public class FileDownload extends ActionSupport{ private int number ; private String fileName; public int getNumber() { return number; } public void setNumber(int number) { this.number = number; } public String getFileName() { return fileName; } public void setFileName(String fileName) { this.fileName = fileName; } //返回一個輸入流，作為一個客戶端來說是一個輸入流，但對于服務器端是一個 輸出流 public InputStream getDownloadFile() throws Exception { if(1 == number) { this.fileName = "Dream.jpg" ; //獲取資源路徑 return ServletActionContext.getServletContext().getResourceAsStream("upload/Dream.jpg") ; } else if(2 == number) { this.fileName = "jd2chm源碼生成chm格式文檔.rar" ; //解解亂碼 this.fileName = new String(this.fileName.getBytes("GBK"),"ISO-8859-1"); return ServletActionContext.getServletContext().getResourceAsStream("upload/jd2chm源碼生成chm格式文檔.rar") ; } else return null ; } @Override public String execute() throws Exception { return SUCCESS; } } 二)在struts.xml文件中配置相關信息
<struts> <package name="struts2" extends="struts-default"> <action name="FileDownload" class="com.struts2.filedownload.FileDownload"> <result name="success" type="stream"> <param name="contentType">text/plain</param> <param name="contentDisposition">attachment;fileName="${fileName}"</param> <param name="inputName">downloadFile</param> <param name="bufferSize">1024</param> </result> </action> </package> </struts> 1.結果類型必須要寫成 type="stream" ,與之對應的處理類是 org.apache.struts2.dispatcher.StreamResult
2.涉及到的參數(shù)：
3.
1) <param name="contentDisposition">attachment;fileName="${fileName}"</param>
contentDisposition默認是 inline（內(nèi)聯(lián)的), 比如說下載的文件是文本類型的，就直接在網(wǎng)頁上打開，不能直接打開的才會打開下載框自己選擇
2) attachment ：下載時會打開下載框
3) fileName="${fileName}" ：在這定義的名字是一個動態(tài)的，該名字是顯示在下載框上的文件名字
4.<param name="inputName">downloadFile</param>，這個downloadFile名字要和FileDownload.java類中的getDownloadFile()方法名去掉get 一致
三）用于顯示下載的鏈接界面 filedownload.jsp
<%@ 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>My JSP 'filedownload.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> <h2>文件下載內(nèi)容：</h2><br/> Dream.jpg:<a href="FileDownload.action?number=1">點擊下載</a><br/> jd2chm源碼生成chm格式文檔.rar:<a href="FileDownload.action?number=2">點擊下載2</a> </body> </html>
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