Struts2.1笔记(九):上传和下载文件
8.1 上传文件完成前的两个必要操作
1.表单的enctype属性设置为multipart/form-data
2.method="post"
8.2上传框架
常用的上传框架有：Common-FileUpload和COS
8.2.1下载Common-FileUpload框架
Common-FileUpload
Common-IO
8.3 Struts2的文件上传
步骤：
a.编写文件的上传页面
b.实现文件上传的Action
c.配置文件上传的Action
8.3.1 拦截器实现文件过滤
配置fileUpload拦截器 两个重要参数
allowedTypes：允许上传的文件类型。
maximumSize：允许上传文件的大小。
8.4使用Struts2控制文件下载
步骤：
a.编写下载页面
b.实现文件下载的Action
c.配置文件下载的Action
配置时的3个重要属性
contentType：下载文件的文件类型
inputName：下载文件的入口输入流
contentDisposition：下载的文件名
下面是一个文件上传和下载的实例代码
1.可以自定义实现上传数量的实例
upload.JSP代码
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Insert title here</title>
<script type="text/javascript">
function addMore(){
var td = document.getElementById("td");
var br =document.createElement("br");
var input=document.createElement("input");
var button=document.createElement("input");
input.type="file";
input.name="file";
button.type="button";
button.value="ReMove";
button.onclick = function(){
td.removeChild(br);
td.removeChild(input);
td.removeChild(button);
}
td.appendChild(br);
td.appendChild(input);
td.appendChild(button);
}
</script>
</head>
<body>
<s:form action="upload" enctype="multipart/form-data" theme="simple">
<table align="center" width="50%" border="1">
<tr>
<td>Title</td>
<td><s:textfield name="title" label="title" id="titleId"></s:textfield>
</td>
</tr>
<tr>
<td>upload</td>
<td id="td"><s:file name="file" label="file"></s:file><input type="button" value="AddMore..." onclick="addMore()"></td>
</tr>
<tr>
<td><s:submit value=" submit "></s:submit></td>
<td><s:reset value=" reset "></s:reset></td>
</tr>
</table>
</s:form>
</body>
</html>
UploadAction代码
package com.test.action;
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 com.opensymphony.xwork2.ActionSupport;
public class UploadAction extends ActionSupport {
private List<String> title;
private List<File> file;
private List<String> fileFileName;
private List<String> fileContentType;
public String execute() throws Exception {
for (int i = 0; i < file.size(); i++) {
InputStream is = new FileInputStream(file.get(i));
File f = new File("D:", this.getFileFileName().get(i));
OutputStream os = new FileOutputStream(f);
byte[] buffer = new byte[400];
int length = 0;
while ((length = is.read(buffer)) > 0) {
os.write(buffer, 0, length);
}
is.close();
os.close();
}
return SUCCESS;
}
public List<String> getTitle() {
return title;
}
public void setTitle(List<String> title) {
this.title = title;
}
public List<File> getFile() {
return file;
}
public void setFile(List<File> file) {
this.file = file;
}
public List<String> getFileFileName() {
return fileFileName;
}
public void setFileFileName(List<String> fileFileName) {
this.fileFileName = fileFileName;
}
public List<String> getFileContentType() {
return fileContentType;
}
public void setFileContentType(List<String> fileContentType) {
this.fileContentType = fileContentType;
}
}
struts.xml
<?xml version="1.0" encoding="GBK"?>
<!-- 指定Struts 2配置文件的DTD信息 -->
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1//EN"
"http://struts.apache.org/dtds/struts-2.1.dtd">
<!-- struts是Struts 2配置文件的根元素 -->
<struts>
<constant name="struts.custom.i18n.resources" value="message"></constant>
<constant name="struts.i18n.encoding" value="gbk"></constant>
<constant name="struts.multipart.saveDir" value="D:/"></constant>
<package name="Struts2" extends="struts-default">
<action name="upload" class="com.test.action.UploadAction">
<result name="success">/Result2.jsp</result>
<result name="input">/upload2.jsp</result>
<interceptor-ref name="fileUpload">
<param name="allowedTypesSet">
application/vnd.ms-word
</param>
</interceptor-ref>
<interceptor-ref name="defaultStack"></interceptor-ref>
</action>
</package>
</struts>
---------------------------------------------------------------
2.限制只能下载ppt格式的文件
download.JSP代码
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Insert title here</title>
</head>
<body>
<s:a href="/Struts2/download.action">down</s:a>
</body>
</html>
DownLoadAction.java代码
package com.test.action;
import java.io.InputStream;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class DownLoadAction extends ActionSupport {
public InputStream getDownFile() {
return ServletActionContext.getServletContext().getResourceAsStream(
"/upload/Struts2.ppt");
}
@Override
public String execute() throws Exception {
return SUCCESS;
}
}
struts.xml配置
<?xml version="1.0" encoding="GBK"?>
<!-- 指定Struts 2配置文件的DTD信息 -->
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1//EN"
"http://struts.apache.org/dtds/struts-2.1.dtd">
<!-- struts是Struts 2配置文件的根元素 -->
<struts>
<constant name="struts.custom.i18n.resources" value="message"></constant>
<constant name="struts.i18n.encoding" value="gbk"></constant>
<constant name="struts.multipart.saveDir" value="D:/"></constant>
<package name="Struts2" extends="struts-default">
<action name="download"
class="com.test.action.DownLoadAction">
<result name="success" type="stream">
<param name="contentType">
application/vnd.ms-powerpoint
</param>
<param name="contentDispostion">
filename="Struts2.ppt"
</param>
<param name="inputName">downFile</param>
</result>
</action>
</package>
</struts>