1.FileUploadServlet.java文件,实现上传处理
import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.text.DecimalFormat; import java.util.Iterator; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; public class FileUploadServlet extends HttpServlet { private static final long serialVersiOnUID= 1L; public FileUploadServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { final long MAX_SIZE = 2048 * 1024 * 1024;// 设置上传文件最大值为2G,可以改为更大 // 允许上传的文件格式的列表 final String[] allowedExt = new String[] { "exe","jpg","DT" }; response.setContentType("text/html"); // 设置字符编码为UTF-8, 统一编码,处理出现乱码问题 response.setCharacterEncoding("UTF-8"); // 实例化一个硬盘文件工厂,用来配置上传组件ServletFileUpload DiskFileItemFactory dfif = new DiskFileItemFactory(); // 用以上工厂实例化上传组件 ServletFileUpload sfu = new ServletFileUpload(dfif); // 设置最大上传大小 sfu.setSizeMax(MAX_SIZE); PrintWriter out = response.getWriter(); // 从request得到所有上传域的列表 List fileList = null; try { fileList = sfu.parseRequest(request); } catch (FileUploadException e) {// 处理文件尺寸过大异常 if (e instanceof SizeLimitExceededException) { out.println("文件尺寸超过规定大小:" + MAX_SIZE + "字节"); out.println("返回"); return; } e.printStackTrace(); } // 没有文件上传 if (fileList == null || fileList.size() == 0) { out.println("请选择上传文件"); out.println("返回"); return; } //文件大小取两位小数 DecimalFormat digit=new DecimalFormat("0.00"); // 得到所有上传的文件 Iterator fileItr = fileList.iterator(); // 循环处理所有文件 while (fileItr.hasNext()) { FileItem fileItem = null; String path = null; double size = 0; // 得到当前文件 fileItem = (FileItem) fileItr.next(); // 忽略简单form字段而不是上传域的文件域(等) if (fileItem == null || fileItem.isFormField()) { continue; } // 得到文件的大小,K为单位并保留两位小数 size = (double)fileItem.getSize()/1024; if ("".equals(path) || size == 0) { out.println(""); out.println("请选择上传文件"); out.println("返回"); out.println(""); return; } // 得到文件的完整路径 path = fileItem.getName(); // 得到去除路径的文件名 String t_name = path.substring(path.lastIndexOf("\\") + 1); // 得到文件的扩展名(无扩展名时将得到全名) String t_ext = t_name.substring(t_name.lastIndexOf(".") + 1); // 拒绝接受规定文件格式之外的文件类型 int allowFlag = 0; int allowedExtCount = allowedExt.length; for (; allowFlag"); for (allowFlag = 0; allowFlag 返回"); out.println(""); return; } try { // 保存文件到服务器根目录下 fileItem.write(new File("\\"+t_name)); System.out.println(t_name); out.println(""); out.println("文件名称为:" + path + "
"); out.println("文件上传成功, 已保存为: " + t_name + "
"+" 文件大小: " + digit.format(size) + "K "); out.println("继续上传"); out.println(""); } catch (Exception e) { e.printStackTrace(); } } } }
2.FileUpload.html文件,实现上传页面。
3.配置web.xml文件中的的servlet和过滤器,过滤器解决上传文件名为中文时出现乱码。
<&#63;xml version="1.0" encoding="UTF-8"&#63;>FileUploadServlet FileUploadServlet FileUploadServlet FileUploadServlet /FileUploadServlet setCharacterEncoding com.xulu.EncodingChange ignore true encoding UTF-8 setCharacterEncoding /* index.jsp BASIC
4.过滤器文件EncodingChange.java和setCharacterEncoding.java分别如下,并且在根目录下的WEB-INF\classes\com\xulu文件夹中放入他它们编译生成的.class文件
package com.xulu; import java.io.IOException; import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class EncodingChange implements Filter { protected String encoding = null; protected FilterConfig filtercOnfig= null; protected boolean ignore = true; public void destroy() { this.encoding = null; this.filtercOnfig= null; } public void doFilter(ServletRequest requests, ServletResponse responses, FilterChain chain) throws IOException, ServletException { // TODO Auto-generated method stub HttpServletRequest request = (HttpServletRequest) requests; HttpServletResponse respOnse= (HttpServletResponse) responses; if (ignore || request.getCharacterEncoding() == null) { String encoding = selectEncoding(request); if (encoding != null) { request.setCharacterEncoding(encoding); request.getSession().getAttribute("Login_Student"); request.getSession().getAttribute("Login_Teacher"); request.getSession().getAttribute("Login_Admin"); } } chain.doFilter(request, response); } public void init(FilterConfig filterconfig) throws ServletException { // TODO Auto-generated method stub this.filtercOnfig= filterconfig; this.encoding = filterconfig.getInitParameter("encoding"); String value = filterconfig.getInitParameter("ignore"); if (value == null) { this.ignore = true; } else if (value.equalsIgnoreCase("true")) { this.ignore = true; } else if (value.equalsIgnoreCase("yes")) { this.ignore = true; } else { this.ignore = false; } } public String selectEncoding(ServletRequest request) { return this.encoding; } } 和 package com.xulu; import java.io.IOException; import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class setCharacterEncoding implements Filter{ protected String encoding=null; protected FilterConfig filtercOnfig=null; protected boolean ignore=true; public void destroy() { this.encoding=null; this.filtercOnfig=null; } public void doFilter(ServletRequest requests, ServletResponse responses, FilterChain chain) throws IOException, ServletException { // TODO Auto-generated method stub HttpServletRequest request=(HttpServletRequest)requests; HttpServletResponse respOnse=(HttpServletResponse)responses; if(ignore||request.getCharacterEncoding()==null){ String encoding=selectEncoding(request); if(encoding!=null){ request.setCharacterEncoding(encoding); request.getSession().getAttribute("Login_Student"); request.getSession().getAttribute("Login_Teacher"); request.getSession().getAttribute("Login_Admin"); } } chain.doFilter(request, response); } public void init(FilterConfig filterconfig) throws ServletException { // TODO Auto-generated method stub this.filtercOnfig= filterconfig; this.encoding = filterconfig.getInitParameter("encoding"); String value = filterconfig.getInitParameter("ignore"); if (value == null) { this.ignore = true; } else if (value.equalsIgnoreCase("true")) { this.ignore = true; } else if (value.equalsIgnoreCase("yes")) { this.ignore = true; } else { this.ignore = false; } } public String selectEncoding(ServletRequest request){ return this.encoding; } }
5.在浏览器中就可以实现页面的上传了,访问http://localhost:8080/**/FileUpload.html就可以了。其中**为自己命名的web文件夹,如DoUpload,上面的文件都在该目录里,且DoUpload文件夹放在Tomcat的webapp文件夹下。
补充:在上述所有步骤之前需引入三个.jar文件,分别为commons-fileupload-1.2.1.jar,commons-io-1.4.jar和servlet-api.jar网上可以下载到
以上就是小编为大家带来的用fileupload组件实现的大文件上传简单实例的全部内容了,希望对大家有所帮助,多多支持~