structs简单文件上传

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本文介绍使用Struts框架实现文件上传的方法，包括创建必要的类、配置文件设置及实现文件类型与大小限制。

导入struts库

建2个包actions 和 forms包

UploadForm类

package forms; import org.apache.struts.action.ActionForm; import org.apache.struts.upload.FormFile; public class UploadForm extends ActionForm { private FormFile myfile; public FormFile getMyfile() { return myfile; } public void setMyfile(FormFile myfile) { this.myfile = myfile; } }

UploadAction类

package actions; import java.io.FileOutputStream; import java.io.PrintWriter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.struts.action.Action; import org.apache.struts.action.ActionForm; import org.apache.struts.action.ActionForward; import org.apache.struts.action.ActionMapping; import org.apache.struts.upload.FormFile; import com.sun.org.apache.xml.internal.serialize.Printer; import forms.UploadForm; public class UploadAction extends Action{ @Override public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception { UploadForm uploadForm=(UploadForm)form; FormFile formfile=uploadForm.getMyfile(); int fsize=formfile.getFileSize();//得到文件大小 String fname=formfile.getFileName();//得到文件名 if(!(fsize==0||fname.equals(""))) {//如果文件大小不为0或文件名不为空的话就上传到c盘下 FileOutputStream fos=new FileOutputStream("c://"+fname); fos.write(formfile.getFileData());//写入字节 fos.flush(); fos.close(); return mapping.findForward("success"); } else { return mapping.findForward("error"); } } }

struts-config.xml文件配置

<?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"> <struts-config> <form-beans> <form-bean name="uploadForm" type="forms.UploadForm"/> </form-beans> <action-mappings> <action path="/upload" name="uploadForm" scope="request" type="actions.UploadAction"> <forward name="error" path="/error.jsp"/> <forward name="success" path="/success.jsp"/> </action> </action-mappings> <message-resources parameter="com.yourcompany.struts.ApplicationResources" /> </struts-config>

index.jsp文件

<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>上传成功</title> </head> <body> <form action="upload.do" method="post" enctype="multipart/form-data"> 文件路径:<input type="file" name="myfile"><br/> <input type="submit" value="上传"> </form> </body> </html>

index.jsp文件中的form中需加入enctype属性值为multipart/form-data

只实现了简单的文件上传，若文件太大将卡死，也没有进行上传文件类型的判断

存在安全隐患

复杂的action

package actions; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.util.ArrayList; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.struts.action.Action; import org.apache.struts.action.ActionForm; import org.apache.struts.action.ActionForward; import org.apache.struts.action.ActionMapping; import org.apache.struts.upload.FormFile; import forms.UploadForm; public class UploadAction extends Action { @Override public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception { UploadForm uploadForm=(UploadForm)form; FormFile myfile=uploadForm.getMyfile(); //控制文件上传类型 List list=new ArrayList(); list.add("jpg"); list.add("rar"); list.add("jsp"); //获取文件后缀名 String fname=myfile.getFileName(); int fsize=myfile.getFileSize(); if(fsize!=0&&!fname.trim().equals("")) { String ext=fname.substring(fname.lastIndexOf('.')+1,fname.length()); System.out.println(ext); String dir = servlet.getServletContext().getRealPath("/"); System.out.println(dir); // if(!list.contains(ext.toLowerCase())) // { // return mapping.findForward("error"); // } // else if(fsize>1024*1) // { // System.out.println("文件太大！"); // return mapping.findForward("error"); // } // else // { try { InputStream in=myfile.getInputStream(); FileOutputStream out=new FileOutputStream(dir+fname); byte[] bytes=new byte[4096]; int byteread=0; int i=0; while((byteread=in.read(bytes))!=-1)//每次读取4096个字节即byteread=4096 { out.write(bytes);//规定byteread-0的字节长度写入bytes中（注意长度不能超过4096）// /* * public void write(byte[] b) throws IOException将 b.length 个字节从指定的字节数组写入此输出流。 write(b) 的常规协定是：应该与调用 write(b, 0, b.length) 的效果完全相同。 public void write( byte[] b, int off, int len) throws IOException 如果 off 为负，或 len 为负，或者 off+len 大于数组 b 的长度，则抛出 IndexOutOfBoundsException */ System.out.println("-------------"+byteread); i++; } out.close(); in.close(); System.out.println("-------------"+i); } catch(Exception e) { e.printStackTrace(); } System.out.println(fsize); return mapping.findForward("success"); // } } return mapping.findForward("index"); } }