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Struts2文件下载-绝对路径/相对路径

2017-02-09 12:17 295 查看
项目代码+jar包下载导入即可使用

下载地址:http://download.csdn.net/detail/love_xiolan/9750719

文件下载是一个很常见的功能,用struts2实现文件下载的步骤:

package download;

import java.io.FileInputStream;
import java.io.InputStream;

import com.opensymphony.xwork2.ActionSupport;

//文件下载
public class FileDownload extends ActionSupport {

private int number;

private String fileName;

private String urlname;

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;
}

// 返回一个输入流,作为一个客户端来说是一个输入流,但对于服务器端是一个 输出流
public InputStream getDownloadFile() throws Exception {
if (1 == number) {
this.fileName = "Dream.jpg";
//File f = new File("C:/Users/Administrator/Pictures/222.jpg");
return new FileInputStream(urlname);
// 获取资源路径
//return ServletActionContext.getServletContext().getResourceAsStream("");
}

else if (2 == number) {
this.fileName = "jd2chm源码生成chm格式文档.rar";
// 解解乱码
this.fileName = new String(this.fileName.getBytes("GBK"), "ISO-8859-1");
//return ServletActionContext.getServletContext().getResourceAsStream("upload/jd2chm源码生成chm格式文档.rar");
return new FileInputStream(urlname);
} else
return null;
}

@Override
public String execute() throws Exception {

return SUCCESS;
}

public String getUrlname() {
return urlname;
}

public void setUrlname(String urlname) {
this.urlname = urlname;
}

}


二)在struts.xml文件中配置相关信息

<?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.i18n.encoding" value="utf8" />
<constant name="struts.multipart.maxSize" value="16777216"></constant>
<package name="struts2" extends="struts-default">
<action name="FileDownload" class="download.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.结果类型必须要写成 type="stream"  ,与之对应的处理类是 org.apache.struts2.dispatcher.StreamResult
2.涉及到的参数:



3.

1)  <param name="contentDisposition">attachment;fileName="${fileName}"</param>

     contentDisposition默认是 inline(内联的), 比如说下载的文件是文本类型的,就直接在网页上打开,不能直接打开的才会打开下载框自己选择

2)  attachment :下载时会打开下载框

3)  fileName="${fileName}" :在这定义的名字是一个动态的,该名字是显示在下载框上的文件名字

4.<param name="inputName">downloadFile</param>,这个downloadFile名字要和FileDownload.java类中的getDownloadFile()方法名去掉get 一致

三)用于显示下载的链接界面 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>文件下载</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>文件下载内容:</h2><br/>
Dream.jpg:<a href="FileDownload.action?number=1&urlname=c:/testindex.txt">点击下载</a><br/>
jd2chm源码生成chm格式文档.rar:<a href="FileDownload.action?number=2&urlname=c:/testindex.txt">点击下载2</a>

确保c盘根目录存在testindex.txt这个文件
</body>
</html>


转载地址:http://blog.csdn.net/hzc543806053/article/details/7538723
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