cos是O'Rrilly公司开发的一款用于HTTP上传文件的OpenSource组件。下面通过本文给大家分享使用COS实现文件上传功能，感兴趣的朋友一起看看吧
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
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
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>
启动上传：
服务端：
总结
以上就是Java中关于使用COS实现文件上传功能的详解的详细内容，更多请关注其它相关文章！
或许是某座闻名遐迩的文化古城。我们可以沿途用镜头记录彼此的笑脸，
