commons-fileupload

Apache Commons fileUpload实现文件上传 2007-02-24 10:38:16

标签：文件上传 Commons Apache 休闲 fileUpload

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Apache的commons-fileupload.jar可方便的实现文件的上传功能，本文通过实例来介绍如何使用commons-fileupload.jar。

@author:ZJ 07-2-22

Blog: [url]http://zhangjunhd.blog.51cto.com/[/url]

    将Apache的commons-fileupload.jar放在应用程序的WEB-INF\lib下，即可使用。下面举例介绍如何使用它的文件上传功能。

所使用的fileUpload版本为1.2，环境为Eclipse3.3+MyEclipse6.0。FileUpload 是基于 Commons IO的，所以在进入项目前先确定Commons IO的jar包（本文使用commons-io-1.3.2.jar）在WEB-INF\lib下。

此文作示例工程可在文章最后的附件中下载。

示例1

最简单的例子，通过ServletFileUpload静态类来解析Request，工厂类FileItemFactory会对mulipart类的表单中的所有字段进行处理，不只是file字段。getName（）得到文件名，getString（）得到表单数据内容，isFormField（）可判断是否为普通的表单项。

demo1.html

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > File upload </ title > </ head > < body >        //必须是multipart的表单数据。     < form name = "myform" action = "demo1.jsp" method = "post"        enctype = "multipart/form-data" >        Your name: <br>        < input type = "text" name = "name" size = "15" >< br >        File:<br>        < input type = "file" name = "myfile" >< br >        < br >        < input type = "submit" name = "submit" value = "Commit" >     </ form > </ body > </ html >

 

demo1.jsp

<%@ page language = "java" contentType = "text/html; charset=GB18030"     pageEncoding = "GB18030" %> <%@ page import = "org.apache.commons.fileupload.*" %> <%@ page import = "org.apache.commons.fileupload.servlet.*" %> <%@ page import = "org.apache.commons.fileupload.disk.*" %> <%@ page import = "java.util.*" %>   <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > <%     boolean isMultipart = ServletFileUpload.isMultipartContent(request);//检查输入请求是否为multipart表单数据。     if (isMultipart == true) {        FileItemFactory factory = new DiskFileItemFactory();//为该请求创建一个DiskFileItemFactory对象，通过它来解析请求。执行解析后，所有的表单项目都保存在一个List中。        ServletFileUpload upload = new ServletFileUpload(factory);        List<FileItem> items = upload.parseRequest(request);        Iterator<FileItem> itr = items.iterator();        while (itr.hasNext()) {            FileItem item = (FileItem) itr.next();            // 检查当前项目是普通表单项目还是上传文件。            if (item.isFormField()) {//如果是普通表单项目，显示表单内容。        String fieldName = item.getFieldName();        if (fieldName.equals("name")) //对应demo1.html中type="text" name="name"            out.print("the field name is" + item.getString());//显示表单内容。        out.print("<br>");            } else {//如果是上传文件，显示文件名。        out.print("the upload file name is" + item.getName());        out.print("<br>");            }        }     } else {        out.print("the enctype must be multipart/form-data");     } %> < html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > File upload </ title > </ head > < body > </ body > </ html >

结果：

the field name isjeff the upload file name isD:\C语言考试样题\作业题.rar

示例2

上传两个文件到指定的目录。

demo2.html

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > File upload </ title > </ head > < body >     < form name = "myform" action = "demo2.jsp" method = "post"        enctype = "multipart/form-data" >        File1:<br>        < input type = "file" name = "myfile" >< br >        File2:<br>        < input type = "file" name = "myfile" >< br >        < br >        < input type = "submit" name = "submit" value = "Commit" >     </ form > </ body > </ html >

 

demo2.jsp

<%@ page language = "java" contentType = "text/html; charset=GB18030"     pageEncoding = "GB18030" %> <%@ page import = "org.apache.commons.fileupload.*" %> <%@ page import = "org.apache.commons.fileupload.servlet.*" %> <%@ page import = "org.apache.commons.fileupload.disk.*" %> <%@ page import = "java.util.*" %> <%@ page import = "java.io.*" %>   <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > <% String uploadPath= "D:\\temp" ;   boolean isMultipart = ServletFileUpload.isMultipartContent(request);   if(isMultipart==true){       try{         FileItemFactory factory = new DiskFileItemFactory();         ServletFileUpload upload = new ServletFileUpload(factory);         List<FileItem> items = upload.parseRequest(request);//得到所有的文件        Iterator<FileItem> itr = items.iterator();         while(itr.hasNext()){//依次处理每个文件          FileItem item=(FileItem)itr.next();          String fileName=item.getName();//获得文件名，包括路径          if(fileName!=null){              File fullFile=new File(item.getName());              File savedFile=new File(uploadPath,fullFile.getName());              item.write(savedFile);          }         }         out.print("upload succeed");       }       catch(Exception e){          e.printStackTrace();       }   }   else{       out.println("the enctype must be multipart/form-data");   } %> < html > < head > < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" > < title > File upload </ title > </ head > < body > </ body > </ html >

结果：

upload succeed

此时，在"D:\temp"下可以看到你上传的两个文件。

示例3

上传一个文件到指定的目录，并限定文件大小。

demo3.html

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > File upload </ title > </ head > < body >     < form name = "myform" action = "demo3.jsp" method = "post"        enctype = "multipart/form-data" >        File:<br>        < input type = "file" name = "myfile" >< br >        < br >        < input type = "submit" name = "submit" value = "Commit" >     </ form > </ body > </ html >

 

demo3.jsp

<%@ page language = "java" contentType = "text/html; charset=GB18030"     pageEncoding = "GB18030" %> <%@ page import = "org.apache.commons.fileupload.*" %> <%@ page import = "org.apache.commons.fileupload.servlet.*" %> <%@ page import = "org.apache.commons.fileupload.disk.*" %> <%@ page import = "java.util.*" %> <%@ page import = "java.io.*" %>   <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > <%     File uploadPath = new File("D:\\temp");//上传文件目录     if (!uploadPath.exists()) {        uploadPath.mkdirs();     }     // 临时文件目录     File tempPathFile = new File("d:\\temp\\buffer\\");     if (!tempPathFile.exists()) {        tempPathFile.mkdirs();     }     try {        // Create a factory for disk-based file items        DiskFileItemFactory factory = new DiskFileItemFactory();          // Set factory constraints        factory.setSizeThreshold(4096); // 设置缓冲区大小，这里是4kb        factory.setRepository(tempPathFile);//设置缓冲区目录          // Create a new file upload handler        ServletFileUpload upload = new ServletFileUpload(factory);          // Set overall request size constraint        upload.setSizeMax(4194304); // 设置最大文件尺寸，这里是4MB          List<FileItem> items = upload.parseRequest(request);//得到所有的文件        Iterator<FileItem> i = items.iterator();        while (i.hasNext()) {            FileItem fi = (FileItem) i.next();            String fileName = fi.getName();            if (fileName != null) {        File fullFile = new File(fi.getName());        File savedFile = new File(uploadPath, fullFile               .getName());        fi.write(savedFile);            }        }        out.print("upload succeed");     } catch (Exception e) {        e.printStackTrace();     } %> < html > < head > < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" > < title > File upload </ title > </ head > < body > </ body > </ html >

示例4

利用Servlet来实现文件上传。

Upload.java

package com.zj.sample;   import java.io.File; import java.io.IOException; 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.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload;   @SuppressWarnings ( "serial" ) publicclass Upload extends HttpServlet {     private String uploadPath = "D:\\temp"; // 上传文件的目录     private String tempPath = "d:\\temp\\buffer\\"; // 临时文件目录     File tempPathFile;       @SuppressWarnings ( "unchecked" )     publicvoid doPost(HttpServletRequest request, HttpServletResponse response)            throws IOException, ServletException {        try {            // Create a factory for disk-based file items            DiskFileItemFactory factory = new DiskFileItemFactory();              // Set factory constraints            factory.setSizeThreshold(4096); // 设置缓冲区大小，这里是4kb            factory.setRepository(tempPathFile);// 设置缓冲区目录              // Create a new file upload handler            ServletFileUpload upload = new ServletFileUpload(factory);              // Set overall request size constraint            upload.setSizeMax(4194304); // 设置最大文件尺寸，这里是4MB              List<FileItem> items = upload.parseRequest(request);// 得到所有的文件            Iterator<FileItem> i = items.iterator();            while (i.hasNext()) {               FileItem fi = (FileItem) i.next();               String fileName = fi.getName();               if (fileName != null) {                   File fullFile = new File(fi.getName());                   File savedFile = new File(uploadPath, fullFile.getName());                   fi.write(savedFile);               }            }            System.out.print("upload succeed");        } catch (Exception e) {            // 可以跳转出错页面            e.printStackTrace();        }     }       publicvoid init() throws ServletException {        File uploadFile = new File(uploadPath);        if (!uploadFile.exists()) {            uploadFile.mkdirs();        }        File tempPathFile = new File(tempPath);         if (!tempPathFile.exists()) {            tempPathFile.mkdirs();        }     } }

 

demo4.html

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > File upload </ title > </ head > < body > // action="fileupload" 对应 web.xml 中 <servlet-mapping> 中 <url-pattern> 的设置 .     < form name = "myform" action = "fileupload" method = "post"        enctype = "multipart/form-data" >        File:<br>        < input type = "file" name = "myfile" >< br >        < br >        < input type = "submit" name = "submit" value = "Commit" >     </ form > </ body > </ html >

 

web.xml

< servlet >     < servlet-name > Upload </ servlet-name >     < servlet-class > com.zj.sample.Upload </ servlet-class > </ servlet >   < servlet-mapping >     < servlet-name > Upload </ servlet-name >     < url-pattern > /fileupload </ url-pattern > </ servlet-mapping >

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