Java中使用COS实现文件上传功能_Java教程

cos是o'rrilly公司开发的一款用于http上传文件的opensource组件

需要cos.jar,下载地址：http://www.servlets.com/cos/

cos上传文件很简单，比fileupload还简单：但是上传最大我试了试，是800多兆，超过直接崩溃：

java.io.ioexception: posted content length of 1627105576 exceeds limit of 889192448 --->byte，800多m

Java中使用COS实现文件上传功能

只需一个servelt即可：

									package com.lhy.upload;

									import java.io.file;

									import java.io.fileoutputstream;

									import java.io.ioexception;

									import java.io.outputstream;

									import java.io.printwriter;

									import java.util.enumeration;

									import java.util.uuid;

									import javax.servlet.servletexception;

									import javax.servlet.annotation.webservlet;

									import javax.servlet.http.httpservlet;

									import javax.servlet.http.httpservletrequest;

									import javax.servlet.http.httpservletresponse;

									import com.oreilly.servlet.multipartrequest;

									import com.oreilly.servlet.multipart.filerenamepolicy;

									/**

									 * cosservlet 

									 * 在cos中就一个类，

									 * multipartrequest它是request的包装类。

									 */

									@webservlet(name="cosservlet",urlpatterns="/cosservlet")

									public class cosservlet extends httpservlet{

									 @override

									 protected void dopost(httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {

									  //第一步，声明文件的保存目录

									  string path = getservletcontext().getrealpath("/up");

									  //第二步：文件上传

									  //声明文件重新命名策略,默认的不行不能重命名，自己实现filerenamepolicy接口

									//  filerenamepolicy rename = new defaultfilerenamepolicy();

									  multipartrequest multireq = new multipartrequest(req, path, 1024*1024*100, "utf-8",new myrename());

									  //输出所上传的文件的信息 

									  enumeration filenames = multireq.getfilenames(); 

									  while(filenames.hasmoreelements()){ 

									    string name = (string)filenames.nextelement(); 

									    file file = multireq.getfile(name);//得到上传的文件

									    if(null != file){ 

									      string filename = multireq.getfilesystemname(name);  //取得文件名 

									      string contenttype = multireq.getcontenttype(name);//类型

									      system.out.println("上传的文件: " +filename+"， 文件类型: "+contenttype); 

									    } 

									  } 

									  //输出所提交的表单中其它文本输入域的值 

									  enumeration formvalue = multireq.getparameternames(); 

									  while(formvalue.hasmoreelements()){ 

									    string param = (string)formvalue.nextelement(); 

									    string value = multireq.getparameter(param); 

									    system.out.println(value); 

									  } 

									  //第三步：如果知道input的name，还可以直接获取信息，

									  /*resp.setcontenttype("text/html;charset=utf-8");

									  printwriter out = resp.getwriter();

									  out.print("文件名称1:"+multireq.getoriginalfilename("img1"));

									  out.print("<br/>新名称:"+multireq.getfilesystemname("img1"));

									  out.print("<br/>类型1:"+multireq.getcontenttype("img1"));

									  out.print("<br/>大小1："+multireq.getfile("img1").length());

									  out.print("<br/>说明:"+multireq.getparameter("desc1"));

									  if(multireq.getcontenttype("img1").contains("image/")){

									   out.print("<img width='300px' height='200px' src='"+req.getcontextpath()+"/up/"+multireq.getfilesystemname("img1")+"'></img>");

									  }

									 out.print("<hr/>");

									 out.print("文件名称2:"+multireq.getoriginalfilename("img2"));

									 out.print("<br/>类型2:"+multireq.getcontenttype("img2"));

									 out.print("<br/>大小2："+multireq.getfile("img2").length());

									 out.print("<br/>说明2:"+multireq.getparameter("desc2"));

									// 

									 out.print("<hr/>");

									 out.print("文件名称3:"+multireq.getoriginalfilename("img3"));

									 out.print("<br/>类型3:"+multireq.getcontenttype("img3"));

									 out.print("<br/>大小3："+multireq.getfile("img3").length());

									 out.print("<br/>说明3:"+multireq.getparameter("desc3"));*/

									 }

									}

									/**

									 * 重命名策略，

									 */

									class myrename implements filerenamepolicy{

									 @override

									 public file rename(file file) {

									  string filename = file.getname();

									  string extname = filename.substring(filename.lastindexof("."));

									  string uuid = uuid.randomuuid().tostring().replace("-","");

									  string newname = uuid+extname;//abc.jpg

									  file = new file(file.getparent(),newname);

									  return file;

									 }

									}

表单：

									<form action="<c:url value='/cosservlet'/>" method="post"

									    enctype="multipart/form-data">

									    file1：<input type="file" name="img1"><br /> 说明1：

									    <input type="text" name="desc1"><br />

									    file2：<input type="file" name="img2"><br/>

									    说明2：<input type="text" name="desc2"><br/>

									    file3：<input type="file" name="img3"><br/>

									    说明3：<input type="text" name="desc3"><br/>

									    <input type="submit" />

									  </form>