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
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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。