Struts2实现单文件或多文件上传功能

Z时代
2024-01-10
分类：IT

一、简述

Struts2的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：

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：

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


<%@ 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


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


<%@ 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


<%@ 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


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


<%@ 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


<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

以上是 Struts2实现单文件或多文件上传功能的全部内容，来源链接： utcz.com/p/213266.html