文件上传与下载—>struts
下载时设置前台的响应类型：response.setContentType("application/x-download");
os = response.getOutputStream();
is = new FileInputStream(new File(path));
上传时设置前台的相应类型：response.setContentType("text/html;charset=gb2312");
FileOutputStream fos = new FileOutputStream(tempFile + filePath + "\\" + fileName);
fos.write(fileItem.get());
乱码转换：
EncodeFilter类实现servlet包下的Filter接口doFilter方法中：
request.setCharacterEncoding("UTF-8"); //将请求以UTF-8形式传输
chain.doFilter(request, response); //将请求放行
action中：
UpLoadForm upLoadForm = (UpLoadForm)form;
FormFile photo = upLoadForm.getPhoto(); //FormFile是formBean中定义的文件类型
oracle函数:
nvl(a,b)： 如果a不为空则返回a，否则返回b
nvl(a,b,c)： 如果a不为空则返回b，否则返回c
decode(value,if1,then1,if2,then2,if3,then3,…,else)表示value等于if1时, 结果是then1。。。
select instr(“yuechaotianyuechao”,”ao”,-1,1)position from dual;(-1是开始位置,1是次数) — 17
substr(“abcde”,-6,5 )=null -6是从右往左数第6个位置开始，5是要取得字符串长度
substr(“abcde”,-5,5 )= abcde -6是从右往左数第6个位置开始，5是要取得字符串长度
mod(a,b)： 对a和b取余
row_number() over(partition by … order by …)
UpLoadForm upLoadForm = (UpLoadForm)form;
FormFile photo = upLoadForm.getPhoto();
response.setContentType("text/html;charset=UTF-8"); //设置输出内容格式
String fileName = photo.getFileName();
InputStream contentStream = photo.getInputStream();
String saveDir = this.getServlet().getServletContext().getRealPath("/");
File filePhoto = new File(saveDir,fileName);
FileOutputStream fos = new FileOutputStream(filePhoto );
/**
int len =0;
byte[] buf = new byte[1024]; //创建1024字节的byte数组
while((len = contentStream.read(buf)) != -1) //如果读到内容
{
fos.write(buf,0,len); //将读到的下标从0到len长度的内容输出到文件输出流中
}
*/
fos.write(upLoadForm.getPhoto().getFileData());//代替上面几行
contentStream .close(); //关闭流
fos.close(); //关闭流
第一步：编写页面文件
<%@ page language="java" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<%@includefile="/header.jsp"%>
<title>struts上传文件</title>
</head>
<body>
<h2>使用Struts上传文件</h2>
<hr/>
<form. action="<%=basePath%>strutsfileupload.do?method=upload" method="post"
enctype="multipart/form-data">
<table>
<tr>
<td>请选择要上传的文件</td>
<td>
<input type="file" name="filePath" size="20"/><br/>
</td>
</tr>
<tr>
<td>
<input type="submit" value="上传"/>
</td>
<td>
<a href="<%=basePath%>strutsfileupload.do?method=download&path=fileload/xxxx.txt">我要下载</a>
</td>
</tr>
</table>
</form>
</body>
</html>
第二步：struts-config.xml文件，包含form-bean 和action的配置
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN" "http://struts.apache.org/dtds/struts-config_1_2.dtd">
<data-sources />
<form-beans >
<form-bean name="fileUploadForm"
type="com.xinglongjian.struts.fileupload.FileUploadForm" />
</form-beans>
<global-exceptions />
<global-forwards>
<forward name="error" path="/error/sysError.jsp"></forward>
</global-forwards>
<action-mappings>
<action path="/strutsfileupload" parameter="method" name="fileUploadForm"
type="com.xinglongjian.struts.fileupload.FileUploadAction" >
<forward name="success" path="/struts/success.jsp"></forward>
</action>
</action-mappings>
</struts-config>
第三步：FileUploadForm.java
public class FileUploadForm. extends ActionForm
{
private FormFile filePath; //类型为FormFile，变量filePath与页面的file名称一致。
public FormFile getFilePath()
{
return filePath;
}
public void setFilePath(FormFile filePath)
{
this.filePath = filePath;
}
}
第四步：FileUploadAction.java
public class FileUploadAction extends DispatchAction
{
/**
* 上传文件
* @param mapping
* @param form
* @param request
* @param response
* @return
* @throws Exception
*/
public ActionForward upload(ActionMapping mapping, ActionForm. form, HttpServletRequest request, HttpServletResponse response)throws Exception
{
FileUploadForm. fileForm=(FileUploadForm)form;
FormFile file=fileForm.getFilePath();
String realPath=this.getServlet().getServletContext().getRealPath("/fileload");
if(file==null)
return mapping.findForward("error");
String filename=file.getFileName();
int size=file.getFileSize();
if(size>1024*1024)
return mapping.findForward("error");
InputStream is=null;
BufferedOutputStream bs=null;
try
{
//get a inputstream object form. uploadFile
is=file.getInputStream();
bs=new BufferedOutputStream(new FileOutputStream(realPath+"/"+filename));
byte[] buffer=new byte[20480];
int count=0;
while((count=is.read())!=-1)
bs.write(buffer, 0, count);
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
bs.flush();
bs.close();
is.close();
}
return mapping.findForward("success");
}
/**
* 下载文件
* @param mapping
* @param form
* @param request
* @param response
* @return
* @throws Exception
*/
public ActionForward download(ActionMapping mapping, ActionForm. form, HttpServletRequest request, HttpServletResponse response)throws Exception
{
String path=request.getParameter("path");
String realPath=this.getServlet().getServletContext().getRealPath("/"+path);
File uploadFile=new File(realPath);
InputStream is=new FileInputStream(uploadFile);
OutputStream s=response.getOutputStream();
BufferedInputStream bis=new BufferedInputStream(is);
BufferedOutputStream bos=new BufferedOutputStream(os);
//弹出下载对话框的代码
response.setHeader("Content-disposition", "attachment;filename="+URLEncoder.encode(path,"utf-8"));
int bytesRead=0;
byte[] buffer=new byte[8192];
while((bytesRead=bis.read(buffer, 0, 8192))!=-1)
bos.write(buffer, 0, bytesRead);
bos.close();
is.close();
bis.close();
os.close();
return null;
}
}