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java框架Struts学习--文件上传与下载

2017-08-28 11:05 661 查看
1、导jar包

2、配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 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_2_5.xsd"> 
<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>
</web-app>


3、全局配置struts.xml

<?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>

<!-- 二、总配置文件：引入其他所有配置文件 -->

<include file="constant.xml"></include>
<include file="cn/itcast/a_config/struts.xml"></include>
<include file="cn/itcast/b_config2/config.xml"></include>
<include file="cn/itcast/c_data/data.xml"></include>
<include file="cn/itcast/d_type/type.xml"></include>
<include file="cn/itcast/e_fileupload/upload.xml"></include>

</struts>


4、actionxml配置

constant.xml

<?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>

<!-- 一、全局配置 -->
<!-- 0. 请求数据编码 -->
<constant name="struts.i18n.encoding" value="UTF-8"/>
<!-- 1. 修改Struts默认的访问后缀 -->
<constant name="struts.action.extension" value="action,do,"></constant>
<!-- 2. 修改xml自动重新加载 -->
<constant name="struts.configuration.xml.reload" value="true"/>
<!-- 3. 开启动态方法调用 (默认不开启)-->
<constant name="struts.enable.DynamicMethodInvocation" value="true"/>
<!-- 4. 修改上传文件的最大大小为30M -->
<constant name="struts.multipart.maxSize" value="31457280"/>

</struts>


upload.xml

<?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>

<package name="upload_" extends="struts-default">
<!-- 注意： action 的名称不能用关键字"fileUpload" -->
<action name="fileUploadAction" class="cn.itcast.e_fileupload.FileUpload">

<!-- 限制运行上传的文件的类型 -->
<interceptor-ref name="defaultStack">

<!-- 限制运行的文件的扩展名 -->
<param name="fileUpload.allowedExtensions">txt,jpg,jar</param>

<!-- 限制运行的类型   【与上面同时使用，取交集】
<param name="fileUpload.allowedTypes">text/plain</param>
-->

</interceptor-ref>

<result name="success">/e/success.jsp</result>

<!-- 配置错误视图 -->
<result name="input">/e/error.jsp</result>
</action>

<action name="down_*" class="cn.itcast.e_fileupload.DownAction" method="{1}">
<!-- 列表展示 -->
<result name="list">/e/list.jsp</result>
<!-- 下载操作 -->
<result name="download" type="stream">

<!-- 运行下载的文件的类型:指定为所有的二进制文件类型 -->
<param name="contentType">application/octet-stream</param>

<!-- 对应的是Action中属性： 返回流的属性【其实就是getAttrInputStream()】 -->
<param name="inputName">attrInputStream</param>

<!-- 下载头，包括：浏览器显示的文件名 -->
<param name="contentDisposition">attachment;filename=${downFileName}</param>

<!-- 缓冲区大小设置 -->
<param name="bufferSize">1024</param>
</result>
</action>
</package>
</struts>


5、页面代码

upload.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 'index.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>
<form action="${pageContext.request.contextPath }/fileUploadAction" method="post" enctype="multipart/form-data">
用户名:<input type="text" name="userName"><br/>
文件:<input type="file" name="file1"><br/>

<input type="submit" value="上传">
</form>
</body>
</html>
下载页面list.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>下载列表</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
</head>

<body>
<table border="1" align="center">
<tr>
<td>编号</td>
<td>文件名</td>
<td>操作</td>
</tr>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<c:forEach var="fileName" items="${fileNames}" varStatus="vs">
<tr>
<td>${vs.count }</td>
<td>${fileName }</td>
<td>
<!-- 构建一个url -->
<c:url var="url" value="down_down">
<c:param name="fileName" value="${fileName}"></c:param>
</c:url>

<a href="${url }">下载</a>
</td>
</tr>
</c:forEach>
</table>
</body>
</html>


6.action代码；

FileUpload.java

import java.io.File;

import org.apache.commons.io.FileUtils;
import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class FileUpload extends ActionSupport {

// 对应表单：<input type="file" name="file1">
private File file1;
// 文件名
private String file1FileName;
// 文件的类型(MIME)
private String file1ContentType;
public void setFile1(File file1) {
this.file1 = file1;
}
public void setFile1FileName(String file1FileName) {
this.file1FileName = file1FileName;
}
public void setFile1ContentType(String file1ContentType) {
this.file1ContentType = file1ContentType;
}

@Override
public String execute() throws Exception {
/******拿到上传的文件，进行处理******/
// 把文件上传到upload目录

// 获取上传的目录路径
String path = ServletActionContext.getServletContext().getRealPath("/upload");
// 创建目标文件对象
File destFile = new File(path,file1FileName);
// 把上传的文件，拷贝到目标文件中
FileUtils.copyFile(file1, destFile);

return SUCCESS;
}
}
DownAction.java

import java.io.File;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Map;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

/**
* 文件下载
* 1. 显示所有要下载文件的列表
* 2. 文件下载
* @author Jie.Yuan
*
*/
public class DownAction extends ActionSupport {

/*************1. 显示所有要下载文件的列表*********************/
public String list() throws Exception {

//得到upload目录路径
String path = ServletActionContext.getServletContext().getRealPath("/upload");
// 目录对象
File file  = new File(path);
// 得到所有要下载的文件的文件名
String[] fileNames =  file.list();
// 保存
ActionContext ac = ActionContext.getContext();
// 得到代表request的map (第二种方式)
Map<String,Object> request= (Map<String, Object>) ac.get("request");
request.put("fileNames", fileNames);
return "list";
}

/*************2. 文件下载*********************/

// 1. 获取要下载的文件的文件名
private String fileName;
public void setFileName(String fileName) {
// 处理传入的参数中问题(get提交)
try {
fileName = new String(fileName.getBytes("ISO8859-1"),"UTF-8");
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
// 把处理好的文件名，赋值
this.fileName = fileName;
}

//2. 下载提交的业务方法 (在struts.xml中配置返回stream)
public String down() throws Exception {
return "download";
}

// 3. 返回文件流的方法
public InputStream getAttrInputStream(){
return ServletActionContext.getServletContext().getResourceAsStream("/upload/" + fileName);
}

// 4. 下载显示的文件名（浏览器显示的文件名）
public String getDownFileName() {
// 需要进行中文编码
try {
fileName = URLEncoder.encode(fileName, "UTF-8");
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
return fileName;
}

}
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标签：  java学习笔记 文件上传 文件下载
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