Struts2实现单文件或多文件上传功能

时间:2022-12-02 12:20:30

一、简述

Struts2文件上传其实也是通过拦截器来实现的,只是该拦截器定义为默认拦截器了,所以不用自己去手工配置,<interceptor name="fileUpload" class="org.apache.struts2.interceptor.FileUploadInterceptor"/>

二、指定用户上传文件的大小,有两种方式

1)默认是在default.properties 文件的 struts.multipart.maxSize=2097152  键值指定为2097152 也就是2M,通过计算 2097152/(1024*1024) = 2 M

那我们可以改变其默认值,只要在src目录下,新建一个 struts.properties 文件,指定上传大小 如下:

Struts2实现单文件或多文件上传功能

一次上传只可以上传10M,不管一次上传多少个文件,按总和计算

2)在struts.xml文件中指定,如图:

Struts2实现单文件或多文件上传功能

其实name就对应struts.properties的键,value对应 值

注意:如果即在struts.properties设定文件上传大小,又在struts.xml 设定文件上传大小,则struts.properties的优先级高于struts.xml,一般在一处指定上传大小即可,推荐 struts.properties

三、Struts2之单文件上传

1.fileupload.jsp

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
 <base href="<%=basePath%>" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
  
 <title>My JSP 'fileupload.jsp' starting page</title>
  
 <meta http-equiv="pragma" content="no-cache">
 <meta http-equiv="cache-control" content="no-cache">
 <meta http-equiv="expires" content="0"
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
 <meta http-equiv="description" content="This is my page">
 <!--
 <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
 -->
 
 </head>
 
 <body>
  <!-- enctype 默认是 application/x-www-form-urlencoded -->
  <form action="FileUpload2" enctype="multipart/form-data" method="post" >
   
    用户名:<input type="text" name="usename"> <br/>
    上传文件:<input type="file" name="file1"><br/>
     
    <input type="submit" value="提交"/>
  
  </form>
  
  
  
 </body>
</html>

2.具体处理上传的 FileUpload.java

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package com.struts2.fileupload;
 
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
 
import org.apache.struts2.ServletActionContext;
 
import com.opensymphony.xwork2.ActionSupport;
 
/**
 * 单个文件上传
 * @author Administrator
 * 上传文件其实是上传了两份,
 *
 * 首先将上传的文件保存到 default.properties 文件中 struts.multipart.saveDir键指定的目录中
 * 默认是空的
 * 保存在 Tomcat 6.0\work\Catalina\localhost\struts2目录下以.tmp后缀名的文件
 *
 * 如果要在 struts.multipart.saveDir 指定目录, 则可以在 src文件夹下 建一个 struts.properties,
 * 覆盖 default.properties 的某些键值
 *
 * 还有一份是 存放在自己设定的目录下
 */
public class FileUpload extends ActionSupport {
  
 private String usename ;
 private File file1 ; //具体上传文件的 引用 , 指向临时目录中的临时文件
 private String file1FileName ; // 上传文件的名字 ,FileName 固定的写法
 private String file1ContentType ; //上传文件的类型, ContentType 固定的写法
  
 public String getUsename() {
  return usename;
 }
 public void setUsename(String usename) {
  this.usename = usename;
 }
 public File getFile1() {
  return file1;
 }
 public void setFile1(File file1) {
  this.file1 = file1;
 }
 public String getFile1FileName() {
  return file1FileName;
 }
 public void setFile1FileName(String file1FileName) {
  this.file1FileName = file1FileName;
 }
 public String getFile1ContentType() {
  return file1ContentType;
 }
 public void setFile1ContentType(String file1ContentType) {
  this.file1ContentType = file1ContentType;
 }
  
 @Override
 public String execute() throws Exception {
  //获取文件存储路径
  String path = ServletActionContext.getRequest().getRealPath("/upload");
  //输出流
  OutputStream os = new FileOutputStream(new File(path,file1FileName));
  //输入流
  InputStream is = new FileInputStream(file1);
   
  byte[] buf = new byte[1024];
  int length = 0 ;
   
  while(-1 != (length = is.read(buf) ) )
  {
   os.write(buf, 0, length) ;
  }
  is.close();
  os.close();
   
  return SUCCESS;
 }
  
  
  
 
}

3.最终显示结果的页面,filedemo.jsp

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
 
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
 <base href="<%=basePath%>" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
  
 <title>My JSP 'filedemo.jsp' starting page</title>
  
 <meta http-equiv="pragma" content="no-cache">
 <meta http-equiv="cache-control" content="no-cache">
 <meta http-equiv="expires" content="0"
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
 <meta http-equiv="description" content="This is my page">
 <!--
 <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
 -->
 
 </head>
 
 <body>
 上传成功: <br/>
 usename: <s:property value="usename" /><br/>
 file: <s:property value="file1FileName"/><br/>
 contentType: <s:property value="file1ContentType"/>
  
 </body>
</html>

四、Struts2之多文件上传

1.fileupload.jsp

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
 <base href="<%=basePath%>" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
  
 <title>My JSP 'fileupload.jsp' starting page</title>
  
 <meta http-equiv="pragma" content="no-cache">
 <meta http-equiv="cache-control" content="no-cache">
 <meta http-equiv="expires" content="0"
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
 <meta http-equiv="description" content="This is my page">
 <!--
 <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
 -->
 
 </head>
 
 <body>
  <!-- enctype 默认是 application/x-www-form-urlencoded -->
  <form action="FileUpload2" enctype="multipart/form-data" method="post" >
   
    用户名:<input type="text" name="usename"> <br/>
    上传文件:<input type="file" name="file1"><br/>
    上传文件: <input type="file" name="file1"><br/> <!-- 两个名字相同 都是file1 -->
    <input type="submit" value="提交"/>
  
  </form>
  
  
  
 </body>
</html>

两个上传文件的name属性值要是一样的,后台方便处理

2.具体处理上传文件的FileUpload2.java

多文件上传用集合的方式

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package com.struts2.fileupload;
 
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
 
import org.apache.struts2.ServletActionContext;
 
import com.opensymphony.xwork2.ActionSupport;
 
/**
 * 多文件上传,用集合的方式
 * @author Administrator
 *
 */
 
public class FileUpload2 extends ActionSupport {
  
 private String usename ;
 private List<File> file1 ;
 private List<String> file1FileName ;
 private List<String> file1ContentType ;
  
 public String getUsename() {
  return usename;
 }
 public void setUsename(String usename) {
  this.usename = usename;
 }
 public List<File> getFile1() {
  return file1;
 }
 public void setFile1(List<File> file1) {
  this.file1 = file1;
 }
 public List<String> getFile1FileName() {
  return file1FileName;
 }
 public void setFile1FileName(List<String> file1FileName) {
  this.file1FileName = file1FileName;
 }
 public List<String> getFile1ContentType() {
  return file1ContentType;
 }
 public void setFile1ContentType(List<String> file1ContentType) {
  this.file1ContentType = file1ContentType;
 }
  
 @Override
 public String execute() throws Exception {
   
  //获取文件存储路径
  String path = ServletActionContext.getRequest().getRealPath("/upload");
   
  for(int i = 0 ; i < file1.size() ; i++ )
  {
   OutputStream os = new FileOutputStream(new File(path,file1FileName.get(i)));
    
   InputStream is = new FileInputStream(file1.get(i));
    
   byte[] buf = new byte[1024];
   int length = 0 ;
    
   while(-1 != (length = is.read(buf) ) )
   {
    os.write(buf, 0, length) ;
   }
    
   is.close();
   os.close();
    
  }
   
  return SUCCESS;
 }
 
}

3.用于显示的界面filedemo.jsp

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
 
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
 <base href="<%=basePath%>" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
  
 <title>My JSP 'filedemo2.jsp' starting page</title>
  
 <meta http-equiv="pragma" content="no-cache">
 <meta http-equiv="cache-control" content="no-cache">
 <meta http-equiv="expires" content="0"
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
 <meta http-equiv="description" content="This is my page">
 <!--
 <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
 -->
 
 </head>
 
 <body>
    上传成功:<br/>
  usename:<s:property value="usename"/><br/>
    <!-- 遍历值 -->
    <s:iterator value="file1FileName" id="f"> <!-- id是一个对象,目前是一个字符串集合 可任意命名 -->
             文件:<s:property value="#f"/> <br/>
    <!-- 这里也可以调用方法 <s:property value="#f.toUpperCase()"/> -->
    </s:iterator>
  
  
 </body>
</html>

遍历集合的方式,用struts2提供的标签 iterator 可以实现

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<s:iterator value="file1FileName" id="f"> <!-- id是一个对象,目前是一个字符串集合 可任意命名-->
    文件:<s:property value="#f"/> <br/>
    <!-- 这里也可以调用方法 <s:property value="#f.toUpperCase()"/> -->
    toUpperCase()字符串的方法是把字母转为大写
</s:iterator>

下载链接:

1)Servlet 文件上传  点击打开链接
2)Struts2之下载  点击打开链接

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。