当我还不会使用上传下载的时候,在网上搜了很多关于这方面的文章可惜都不是非常的详细,所以无法理解于使用,现在决定写一篇详细说明!
上传文件使用!
页面重点如下:(红字却一不可!)
提交方式必须为:method="post"
填加enctype="multipart/form-data";

<%...@ page language="java" pageEncoding="utf-8"%>


<%...@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html:html lang="true">
<head>
<html:base />
<title>文件上传</title>

</head>
<body>
<html:form action="upload.do?method=upload" method="post" enctype="multipart/form-data">
<html:file property="file"></html:file>
<br>
<html:submit value="提交"></html:submit>
</html:form>
</body>
</html:html>

ActionForm中必须添加与<html:file property="file">相对应的值必须为FormFile类型

/**//*
* Generated by MyEclipse Struts
* Template path: templates/java/JavaClass.vtl
*/
package com.struts.form;

import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.upload.FormFile;


public class UploadForm extends ActionForm ...{
private FormFile file; //这个属性很重要必须对应页面<html:file property="file"> property中的值,类型为FormFile
public ActionErrors validate(ActionMapping mapping,

HttpServletRequest request) ...{
return null;
}


public void reset(ActionMapping mapping, HttpServletRequest request) ...{
}

/** *//**
* 生成set与get方法别忘咯
* @return
*/

public FormFile getFile() ...{
return file;
}


public void setFile(FormFile file) ...{
this.file = file;
}
}
DispatchAction中进行操作

/**//*
* Generated by MyEclipse Struts
* Template path: templates/java/JavaClass.vtl
*/
package com.struts.action;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.actions.DispatchAction;
import com.struts.form.UploadForm;
import com.upload.MyUpload;


/** *//**
* MyEclipse Struts
* Creation date: 03-28-2008
*
* XDoclet definition:
* @struts.action path="/upload" name="uploadForm" input="/form/upload.jsp" scope="request" validate="true"
*/

public class UploadAction extends DispatchAction ...{

/**//*
* Generated Methods
*/


/** *//**
* Method execute
* @param mapping
* @param form
* @param request
* @param response
* @return ActionForward
*/
public ActionForward upload(ActionMapping mapping, ActionForm form,

HttpServletRequest request, HttpServletResponse response) ...{
UploadForm u = (UploadForm) form;// TODO Auto-generated method stub

/**//*获取WEB服务器的相对路径*/
String path = request.getSession().getServletContext().getRealPath("/");

/**//*封装了一个具体的上传:过程下一部将进行详细介绍*/
MyUpload up=new MyUpload();

try ...{

/**//*存储文件方法需要传入:FormFile类型的实例化对象和路径:下一部将进行详细介绍*/
up.save(u.getFile(), path);

} catch (IOException e) ...{
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}
MyUpload类具体实现上传的类
package com.upload;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.struts.upload.FormFile;


public class MyUpload ...{
private OutputStream os;
private InputStream is;
private byte[] b;
private int leng;

public void save(FormFile file,String path) throws IOException...{

/**//*实例化一个File对象,通过getFileName方法获取文件名*/
os = new FileOutputStream(path+file.getFileName());

/**//*通过file对象getInputStream方法来实例化is*/
is = file.getInputStream();

/**//*设置一个缓冲*/
b = new byte[1024];

while((leng=is.read(b))!=-1)...{//不为-1代表文件读到尾部.详情请参考API文档IO包
os.write(b, 0, leng);
leng=0;
}
os.flush();
os.close();
is.close();
}
}

写到了此已经成功的完成了上传,但是只能为英文所以还需要进行解决中文乱码问题!
首先在web.xml文件中添加如下代码设置过滤器,这个大家应该都比较熟悉了所以不进行一一介绍
毕竟现在已经凌晨3点了
<filter>
<filter-name>filter</filter-name>
<filter-class>com.util.Fileters</filter-class>
<init-param>
<param-name>charset</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
配置好了web.xml那么现在开始实现一个过滤器Fileters,它需要实现Filter这个接口,
package com.util;
import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;



public class Fileters implements Filter ...{
private String charset;


public void destroy() ...{
// TODO Auto-generated method stub

}

public void doFilter(ServletRequest req, ServletResponse res,

FilterChain chain) throws IOException, ServletException ...{
// TODO Auto-generated method stub

/**//*设置request的字符编码*/
req.setCharacterEncoding(charset);

/**//*将request和response传回去,具体为什么请参考jsp基础*/
chain.doFilter(req, res);
}


public void init(FilterConfig config) throws ServletException ...{
// TODO Auto-generated method stub

/**//*获取xml文件中初始化参数charset对应web.xml文件中的<param-name>charset</param-name>将值传给属性charset*/
charset = config.getInitParameter("charset");
}

}

基本功能已经实现,乱码问题以解决,本来想将下载也写出来的,但是时间不够!
明天继续完成下载的详细讲解!
第一次写文章!比较菜哈!如果有什么讲的不对的请高手指出!