Java based servlet uses component Smartupload to implement file uploads _java

File uploads are very common in web apps, and now I'm going to introduce a servlet based file upload, which can be seen based on Struts2 file uploads:

Page End Code:

<%@ page language= "java" import= "java.util.*" pageencoding= "GBK"%> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >  

The point to note here is that there is a form of file upload must be encapsulated as enctype= "Multipart/form-data", where we interact directly with the background, without Ajax interaction, need to use Ajax to see: http:// Www.cnblogs.com/shenliang123/category/372520.html

Let's go on to see the code implementation of the servlet:

Package com.xidian.bbs.servlet;
Import java.io.IOException;
Import Java.io.PrintWriter;
Import java.net.InetAddress;
Import java.sql.Connection;
Import Java.sql.ResultSet;

Import java.sql.Statement;
Import javax.servlet.ServletException;
Import Javax.servlet.http.HttpServlet;
Import Javax.servlet.http.HttpServletRequest;
Import Javax.servlet.http.HttpServletResponse;
Import Javax.servlet.jsp.JspFactory;

Import Javax.servlet.jsp.PageContext;
Import com.jspsmart.upload.*;
Import Com.xidian.bbs.bean.Bean;
Import Com.xidian.bbs.bean.RegisterBean;
Import com.xidian.bbs.util.DBAccess;

Import Com.xidian.bbs.util.IpTimeStamp; @SuppressWarnings ("Serial") public class Registerservlet extends httpservlet{protected void doget (HttpServletRequest
  Request, HttpServletResponse response) throws Servletexception, IOException {response.setcontenttype ("text/html");
  Response.setcharacterencoding ("GBK");
  
  Request.setcharacterencoding ("GBK");
  Smartupload smart=new smartupload ();
 try{ PageContext is the built-in object of JSP, in the servlet cannot be used directly, need to do some processing jspfactory _jspxfactory = null;
   PageContext pagecontext = null;
   _jspxfactory = Jspfactory.getdefaultfactory ();

  PageContext = _jspxfactory.getpagecontext (This,request,response, "", true,8192,true);
  Smart.initialize (PageContext);//initialization upload operation Smart.upload (); Iptimestamp its=new Iptimestamp (Inetaddress.getlocalhost (). gethostaddress ());//request.getremoteaddr () Obtain the user's IP address/
  /SYSTEM.OUT.PRINTLN ("Obtained IP is" +inetaddress.getlocalhost (). gethostaddress ()); If you want to implement a bulk upload of a file, simply use the For loop to change 0 in GetFile (0) to I to String ext=smart.getfiles (). GetFile (0). Getfileext ()//This is the file extension. GetFile (0) to get the only one upload file String filename=its.getiptimerand () + "."
  +ext;
  SYSTEM.OUT.PRINTLN ("Obtained file name is" +filename); This.getservletcontext (). Getrealpath ("/") to get Tomcat's directory, put it in the upload folder, Java.io.File.separator is a safe operation//string
  Realpath= ""; This.getservletcontext (). Getrealpath ("/") + Smart.getfiles (). GetFile (0). SaveAs ("/headupload" +
  Java.io.file.separator+filename); StrinG realpath= "headupload/" +filename+ ""; Since the previous form form has already been encapsulated, it is not easy to use Request.getparameter () to get the form parameter String uname1 = Smart.getrequest (). GetParameter ("
  Uname1 ");//nickname String Upass1 = Smart.getrequest (). GetParameter (" Password1 ");
  String sex = Smart.getrequest (). GetParameter ("Sex"); String uname2 = Smart.getrequest (). GetParameter ("uname2");//username string email = smart.getrequest (). GetParameter ("email
  ");
 
     PrintWriter out = Response.getwriter ();
 The following is the persistence layer operation, omitting ...  } protected void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException
 {doget (request,response);

 }

}

The ip+ timestamp class used above Iptimestamp renames the file:

In the upload file and other operations, we do not let the filename conflict, will be renamed operations, here is a implementation of the ip+ timestamp name:

Directly on the code, there is nothing to say, the implementation is quite simple, but practical

Package com.xidian.bbs.util;
Import Java.text.SimpleDateFormat;
Import Java.util.Date;

Import Java.util.Random;
 The public class Iptimestamp {private SimpleDateFormat sim=null;//is used to get time private String ip=null;
 Public Iptimestamp () {} public iptimestamp (String IP) {this.ip=ip;
  Public String Getiptimerand () {StringBuffer sbf=new stringbuffer ();    if (this.ip!=null) {String a[]=this.ip.split ("\.");   Splits the IP address according to the point, but the point is to escape for (int i=0;i<a.length;i++) {sbf.append (This.addzero (A[i), 3));    Call the method of zeroing, each block of IP less than three bits of automatic replenishment to three-bit} sbf.append (This.gettimestamp ());      Use this to invoke an external method Random random=new Random ();    To generate a random number for (int i=0;i<3;i++) {//Generate three-bit random number sbf.append (Random.nextint (10));
 Each random number is no more than ten} return sbf.tostring (); @SuppressWarnings ("unused") private String getDate () {//about the implementation of the date and time This.sim=new SimpleDateFormat ("Yyyy-mm-dd Hh:mm:ss.
  SSS ");
 Return This.sim.format (New Date ()); Private String Gettimestamp () {//return timestamp
  This.sim=new SimpleDateFormat ("yyyymmddhhmmsssss");
 Return This.sim.format (New Date ());
  private string Addzero (string Str,int len) {//automatic zero-complement method, parameter is the specified string and length StringBuffer s=new stringbuffer ();
  S.append (str);        while (S.length () <len) {s.insert (0, "0");
 0 operation at zero position} return s.tostring (); ///Do test public static void Main (String [] ary) {iptimestamp iptimestamp=new iptimestamp ("172.168.3.222");//Call constructor with arguments
 FA System.out.println (Iptimestamp.getiptimerand ());
 }
}

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