Apache commons fileupload文件上傳實例講授。本站提示廣大學習愛好者：（Apache commons fileupload文件上傳實例講授）文章只能為提供參考，不一定能成為您想要的結果。以下是Apache commons fileupload文件上傳實例講授正文
文件上傳的辦法重要今朝有兩個經常使用的，一個是SmartUpload，一個是Apache的Commons fileupload.
我們這裡重要引見下第二個的用法，起首要上傳文件，留意幾個成績：
1 form表單內，要添加空間<input type="file" name="myfile">
2 form表單的內容格局要界說成multipart/form-data格局
3 須要類庫：1 commons-io.jar 2commons-fileupload-1.3.1.jar
接上去我們看下用法。
起首浏覽Apache commons fileupload的官方文檔可以發明上面幾個經常使用的函數：
1 創立文件解析對象
DiskFileUpload diskFileUpload = new DiskFileUpload();
2 停止文件解析後放在List中，由於這個類庫支撐多個文件上傳，是以把成果會存在List中。
List<FileItem> list = diskFileUpload.parseRequest(request);
3 獲得上傳文件，停止剖析（不是必需）
File remoteFile = new File(new String(fileItem.getName().getBytes(),"UTF-8"));
4 創立新對象，停止流拷貝
file1 = new File(this.getServletContext().getRealPath("attachment"),remoteFile.getName());
file1.getParentFile().mkdirs();
file1.createNewFile();
InputStream ins = fileItem.getInputStream();
OutputStream ous = new FileOutputStream(file1);
try{
byte[] buffer = new byte[1024];
int len = 0;
while((len = ins.read(buffer)) > -1)
ous.write(buffer,0,len);
out.println("以保留文件"+file1.getAbsolutePath()+"<br/>");
}finally{
ous.close();
ins.close();
}
如許我們就完成了文件的上傳。
fileUpload.html
<form action="servlet/UploadServlet" method="post" enctype="multipart/form-data">
<div align="center">
<fieldset >
<legend>上傳文件</legend><br/>
<div align="left">上傳文件1</div>
<div align="left">
<input type="file" name="file1"/>
</div>
<div align="left">上傳文件2</div>
<div align="left">
<input type="file" name="file2"/>
</div>
<div>
<div align='left'>上傳文件解釋1</div>
<div align='left'><input type="text" name="description1"/></div>
</div>
<div>
<div align='left'>上傳文件解釋2</div>
<div align='left'><input type="text" name="description2"/></div>
</div>
<div>
<div align='left'>
<input type='submit' value="上傳文件"/>
</div>
</div>
</fieldset>
</div>
</form>
web.xml
<servlet> <servlet-name>UploadServlet</servlet-name> <servlet-class>com.test.hello.UploadServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>UploadServlet</servlet-name> <url-pattern>/servlet/UploadServlet</url-pattern> </servlet-mapping>
UploadServlet.java
package com.test.hello;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
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.DiskFileUpload;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
public class UploadServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public UploadServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.getWriter().println("請以POST方法上傳文件");
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
@SuppressWarnings({ "unchecked", "deprecation" })
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
File file1 = null,file2=null;
String description1 = null,description2 = null;
response.setCharacterEncoding("UTF-8");
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
DiskFileUpload diskFileUpload = new DiskFileUpload();
try{
List<FileItem> list = diskFileUpload.parseRequest(request);
out.println("遍歷一切的FileItem...<br/>");
for(FileItem fileItem : list){
if(fileItem.isFormField()){
if("description1".equals(fileItem.getFieldName())){
out.println("遍歷到description1 ... <br/>");
description1 = new String(fileItem.getString().getBytes(),"UTF-8");
}
if("description2".equals(fileItem.getFieldName())){
out.println("遍歷到description2 ... <br/>");
description2 = new String(fileItem.getString().getBytes(),"UTF-8");
}
}else{
if("file1".equals(fileItem.getFieldName())){
File remoteFile = new File(new String(fileItem.getName().getBytes(),"UTF-8"));
out.println("遍歷到file1...<br/>");
out.println("客戶端文件地位："+remoteFile.getAbsolutePath()+"<br/>");
file1 = new File(this.getServletContext().getRealPath("attachment"),remoteFile.getName());
file1.getParentFile().mkdirs();
file1.createNewFile();
InputStream ins = fileItem.getInputStream();
OutputStream ous = new FileOutputStream(file1);
try{
byte[] buffer = new byte[1024];
int len = 0;
while((len = ins.read(buffer)) > -1)
ous.write(buffer,0,len);
out.println("以保留文件"+file1.getAbsolutePath()+"<br/>");
}finally{
ous.close();
ins.close();
}
}
if("file2".equals(fileItem.getFieldName())){
File remoteFile = new File(new String(fileItem.getName().getBytes(),"UTF-8"));
out.println("遍歷到file2...<br/>");
out.println("客戶端文件地位："+remoteFile.getAbsolutePath()+"<br/>");
file2 = new File(this.getServletContext().getRealPath("attachment"),remoteFile.getName());
file2.getParentFile().mkdirs();
file2.createNewFile();
InputStream ins = fileItem.getInputStream();
OutputStream ous = new FileOutputStream(file2);
try{
byte[] buffer = new byte[1024];
int len = 0;
while((len = ins.read(buffer)) > -1)
ous.write(buffer,0,len);
out.println("以保留文件"+file2.getAbsolutePath()+"<br/>");
}finally{
ous.close();
ins.close();
}
}
}
out.println("Request 解析終了<br/><br/>");
}
}catch(FileUploadException e){}
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
if(file1 != null){
out.println("<div>");
out.println(" <div align='left'>file1;</div>");
out.println(" <div align='left'><a href='"+request.getContextPath()+"/attachment/"+
file1.getName()+"'target=_blank>"+file1.getName()+"</a>");
out.println("</div>");
out.println("</div>");
}
if(file2 != null){
out.println("<div>");
out.println(" <div align='left'>file2;</div>");
out.println(" <div align='left'><a href='"+request.getContextPath()+"/attachment/"+
file2.getName()+"'target=_blank>"+file2.getName()+"</a>");
out.println("</div>");
out.println("</div>");
}
out.println("<div>");
out.println(" <div align='left'>description1:</div>");
out.println(" <div align='left'>");
out.println(description1);
out.println("</div>");
out.println("</div>");
out.println("<div>");
out.println(" <div align='left'>description2:</div>");
out.println(" <div align='left'>");
out.println(description2);
out.println("</div>");
out.println("</div>");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}
運轉示例
以上就是本文的全體內容，願望對年夜家的進修有所贊助，也願望年夜家多多支撐。
