最近因为一个项目,需要做统一的下载,并且要支持批量下载..其中涉及到的知识点有:get请求中文处理,下载动态设置下载名,批量下载,动态打包,流处理,删除临时文件,使用迅雷下载后台发出两次次下载请求,以及struts2工作流程与原理等..
下面是我自己做的一个实例,主要实现遍历一个文件夹生成下载列表,用户可以单一下载,也可选择相关文件批量下载.....做的其中发现有很多疑惑的地方,请高手们指出....谢谢
一.实例区
1.index.html
<%
@pagelanguage
=
"
java
"
pageEncoding
=
"
gbk
"
%>
<%
String
path
=
request.getContextPath();
String
basePath
=
request.getScheme()
+
"
://
"
+
request.getServerName()
+
"
:
"
+
request.getServerPort()
+
path
+
"
/
"
;
%>
<!
DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML4.01Transitional//EN"
>
<
html
>
<
head
>
<
base
href
="<%=basePath%>"
>
<
title
>
MyJSP'index.jsp'startingpage
</
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
="Thisismypage"
>
<!--
<linkrel="stylesheet"type="text/css"href="styles.css">
-->
</
head
>
<
body
>
<
hr
>
<
h3
>
欢迎光临下载区
</
h3
>
<
a
href
="downloadList.action"
>
下载列表
</
a
><
br
/>
</
body
>
</
html
>
2.配置struts.xml
<?
xmlversion="1.0"encoding="UTF-8"
?>
<!
DOCTYPEstrutsPUBLIC
"-//ApacheSoftwareFoundation//DTDStrutsConfiguration2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd"
>
<
struts
>
<
constant
name
="struts.custom.i18n.resources"
value
="message"
></
constant
>
<
constant
name
="struts.i18n.encoding"
value
="gbk"
></
constant
>
<
constant
name
="struts.multipart.saveDir"
value
="/tmp"
></
constant
>
<
constant
name
="struts.multipart.maxSize"
value
="209715200"
/>
<
package
name
="struts2"
extends
="struts-default"
>
<
action
name
="downloadList"
class
="cn.edu.cuit.disasterSystem.web.struts2.action.DownloadListAction"
>
<
result
name
="success"
>
/downloadList.jsp
</
result
>
<
result
name
="error"
>
/downloadListError.jsp
</
result
>
</
action
>
<
action
name
="download"
class
="cn.edu.cuit.disasterSystem.web.struts2.action.DownloadAction"
>
<
result
name
="success"
type
="stream"
>
<!--
contentType为二进制方式
-->
<
param
name
="contentType"
>
application/octet-stream;charset=ISO8859-1
</
param
>
<!--
attachment属性强调是下载,就不会主动打开,比如图片
-->
<!--
使用经过转码的文件名作为下载文件名,downloadFileName属性对应action类中的方法getDownloadFileName()
-->
<
param
name
="contentDisposition"
>
attachment;filename=${filename}
</
param
>
<
param
name
="inputName"
>
downloadFile
</
param
>
<
param
name
="bufferSize"
>
4096
</
param
>
</
result
>
<
result
name
="input"
>
/downloadList.jsp
</
result
>
<
result
name
="error"
>
/downloadListError.jsp
</
result
>
</
action
>
</
package
>
</
struts
>
3.产生下载列表的Action----DownloadListAction
package
cn.edu.cuit.disasterSystem.web.struts2.action;
import
java.io.File;
import
java.util.ArrayList;
import
java.util.HashMap;
import
java.util.Map;
import
org.apache.struts2.ServletActionContext;
import
com.opensymphony.xwork2.ActionContext;
import
com.opensymphony.xwork2.ActionSupport;
/**
*显示所有down目录的文件,供下载所用
*
@author
xcp
*
@version
1.0
*Copyright(C),2009智能开发实验室所有
*ProgramName:灾情信息管理系统
*Date:2009-10-24上午11:16:41
*/
@SuppressWarnings(
"
serial
"
)
public
class
DownloadListAction
extends
ActionSupport{
private
static
ArrayList
<
String
>
filelist
=
new
ArrayList
<
String
>
();
/**
*可以是前台一个页面传入,也可以是手动指定,其作用是指定下载文件的根目录
*
@author
向才鹏
*2009-10-24下午12:02:47
*/
private
StringdownloadRootPath
=
"
/upload
"
;
public
StringgetDownloadRootPath(){
return
downloadRootPath;
}
public
void
setDownloadRootPath(StringdownloadRootPath){
this
.downloadRootPath
=
downloadRootPath;
}
/**
*将指定文件路径下的文件全部遍历出来
*
@author
向才鹏
*
@param
strPath指来要遍历的文件
*2009-10-24下午12:04:48
*/
public
static
void
refreshFileList(StringstrPath)
{
Filedir
=
new
File(strPath);
File[]files
=
dir.listFiles();
if
(files
==
null
)
return
;
for
(
int
i
=
0
;i
<
files.length;i
++
)
{
if
(files[i].isDirectory())
{
refreshFileList(files[i].getAbsolutePath());
}
else
{
StringfilePath
=
files[i].getPath();
filelist.add(filePath);
}
}
}
/**
*格式化输出数据存入Map,形式文件名+文件服务端路径
*
@author
向才鹏
*
@param
filelist遍历出来的文件路径
*
@param
downloadRootPath指明服务器下载的文件,便于从遍历出来的文件中取得服务端路径
*
@return
*2009-10-24下午12:06:18
*/
private
static
Map
<
String,String
>
formatFileMap(ArrayList
<
String
>
filelist,StringdownloadRootPath){
Map
<
String,String
>
formatFileMap
=
new
HashMap
<
String,String
>
();
//
得到服务下载的根路径,并将/换成\\,这样便于替换
StringformatDownloadRootPath
=
downloadRootPath.replaceAll(
"
/
"
,
"
\\\\
"
);
for
(StringfilePath:filelist){
//
得到下载的相对路径
StringdownloadPath
=
filePath.substring(filePath.indexOf(formatDownloadRootPath));
//
将得到的相对路径的\\转换成/
StringformatDownloadPath
=
downloadPath.replaceAll(
"
\\\\
"
,
"
/
"
);
//
得到文件名
Stringfilename
=
formatDownloadPath.substring(formatDownloadPath.lastIndexOf(
"
/
"
)
+
1
);
/*
try{
formatFileMap.put(filename,URLEncoder.encode(formatDownloadPath,"gbk"));
}catch(UnsupportedEncodingExceptione){
formatFileMap.put(filename,formatDownloadPath);
e.printStackTrace();
}
*/
//
这就不用考虑设置编码了,再后面统一使用javascript的encodeURI函数
formatFileMap.put(filename,formatDownloadPath);
}
return
formatFileMap;
}
@SuppressWarnings(
"
unchecked
"
)
@Override
public
Stringexecute()
throws
Exception{
//
指定下载目录
Stringupload
=
ServletActionContext.getServletContext().getRealPath(downloadRootPath);
//
清理filelist
filelist.clear();
//
遍历文件
refreshFileList(upload);
ActionContextcontext
=
ActionContext.getContext();
Maprequest
=
(Map)context.get(
"
request
"
);
if
(filelist
!=
null
){
//
格式化文件信息,包括文件名和地址
Map
<
String,String
>
formatFileMap
=
formatFileMap(filelist,downloadRootPath);
request.put(
"
fileMap
"
,formatFileMap);
return
SUCCESS;
}
else
{
request.put(
"
errorMessage
"
,
"
没有相关的下载文件
"
);
return
ERROR;
}
}
}
4.显示下载列表downloadList.jsp
<%
@pagelanguage
=
"
java
"
contentType
=
"
text/html;charset=gbk
"
pageEncoding
=
"
gbk
"
%>
<%
@taglibprefix
=
"
s
"
uri
=
"
/struts-tags
"
%>
<!
DOCTYPEhtmlPUBLIC"-//W3C//DTDHTML4.01Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"
>
<
script
type
="text/javascript"
>
function
downloadFile1(filenames,filepaths){
location.href
=
encodeURI(
"
download.action?filenames=
"
+
filenames
+
"
&filepaths=
"
+
filepaths);
}
function
SelectAll(oForm)
{
for
(
var
i
=
0
;i
<
oForm.url.length;i
++
)
{
oForm.url[i].checked
=
true
;
}
}
function
TurnOver(oForm)
{
for
(
var
i
=
0
;i
<
oForm.url.length;i
++
)
{
oForm.url[i].checked
=!
oForm.url[i].checked;
}
}
function
DownlodSelected(oForm){
if
(confirm(
"
因需要在服务端动态打包,需要时间比较长,是否继续批量下载?
"
))
{
var
arrDownloadList
=
[];
for
(
var
i
=
0
;i
<
oForm.url.length;i
++
){
if
(oForm.url[i].checked
==
true
){
if
(arrDownloadList.length
==
0
){
arrDownloadList[
0
]
=
oForm.url.value;
}
arrDownloadList[arrDownloadList.length]
=
oForm.url[i].value;
}
}
if
(arrDownloadList.length
>
0
){
var
temp
=
[];
var
filenames
=
""
;
var
filepaths
=
""
;
for
(
var
i
=
1
;i
<
arrDownloadList.length;i
++
){
temp
=
arrDownloadList[i].split(
"
,
"
)
if
(filenames
==
""
&&
filepaths
==
""
){
filenames
=
temp[
0
]
filepaths
=
temp[
1
]
}
else
{
filenames
=
filenames
+
"
|
"
+
temp[
0
];
filepaths
=
filepaths
+
"
|
"
+
temp[
1
];
}
}
downloadFile1(filenames,filepaths);
}
else
{
alert(
"
还没有选中下载项
"
);
}
}
}
</
script
>
<
html
>
<
head
>
<
meta
http-equiv
="Content-Type"
content
="text/html;charset=GB18030"
>
<
title
>
Inserttitlehere
</
title
>
<
script
type
="text/javascript"
src
="dwr/engine.js"
></
script
>
<
script
type
="text/javascript"
src
="dwr/util.js"
></
script
>
<
script
type
="text/javascript"
src
="dwr/interface/downloaddwr.js"
></
script
>
</
head
>
<
body
>
<
form
name
="myform"
style
="display:inline"
onSubmit
="returnfalse"
>
<
table
width
="50%"
align
="center"
>
<
tr
>
<
td
colspan
="2"
>
<
h3
>
以后是下载列表,点击进行下载
</
h3
>
</
td
>
</
tr
>
<
tr
>
<
td
colspan
="2"
>
<
font
color
="red"
><
s:fielderror
></
s:fielderror
>
</
font
>
</
td
>
</
tr
>
<
s:iterator
value
="#request.fileMap"
status
="stuts"
>
<
s:if
test
="#stuts.odd==true"
>
<
tr
style
="background-color:#77D9F6"
>
<
td
>
<
input
name
="url"
type
="checkbox"
id
="url"
value
="<s:propertyvalue="
key"
/>
,
<
s:property
value
="value"
/>
">
</
td
>
<
td
>
<
s:property
value
="key"
/>
</
td
>
<
td
>
<
a
href
="#"
onclick
="downloadFile1('<s:propertyvalue="
key"
/>
','
<
s:property
value
="value"
/>
')">点击下载
</
a
>
</
td
>
</
tr
>
</
s:if
>
<
s:else
>
<
tr
style
="background-color:#D7F2F4"
>
<
td
>
<
input
name
="url"
type
="checkbox"
id
="url"
value
="<s:propertyvalue="
key"
/>
,
<
s:property
value
="value"
/>
">
</
td
>
<
td
>
<
s:property
value
="key"
/>
</
td
>
<
td
>
<
a
href
="#"
onclick
="downloadFile1('<s:propertyvalue="
key"
/>
','
<
s:property
value
="value"
/>
')">点击下载
</
a
>
</
td
>
</
tr
>
</
s:else
>
</
s:iterator
>
</
table
>
<
div
align
="center"
>
<
input
class
="green_at_bn"
title
="选择下载的文件"
onClick
="SelectAll(this.form)"
type
="button"
value
="全选"
>
<
input
class
="green_at_bn"
title
="反向选择下载文件"
onClick
="TurnOver(this.form)"
type
="button"
value
="反选"
>
<
input
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