struts2上传图片功能实现（单个图片）

1.搭建struts2框架

   a)导入相关的jar包

           blank实例中的包即可

   b)配置web.xml文件

          

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">  <display-name></display-name>   <filter>        <filter-name>struts2</filter-name>        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>    </filter>    <filter-mapping>        <filter-name>struts2</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list></web-app>

    c)配置struts2.xml文件

      

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE struts PUBLIC"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN""http://struts.apache.org/dtds/struts-2.3.dtd"><struts><!-- 动态调用方法 -->    <constant name="struts.enable.DynamicMethodInvocation" value="false" />    <!-- 开启开发模式，这样可以打印出详细的错误信息 -->    <constant name="struts.devMode" value="true" />        <!-- 访问后缀 ,,表示省略不写--><constant name="struts.actions.extension" value="action,do,,"/><!-- 当struts.xml文件被修改后自动重新部署 --><constant name="struts.configuration.xml.reload" value="true"/><!-- 允许上传的文件的最大字节数 --><constant name="struts.multipart.maxSize" value="2097152"/><!-- 缓存路径 --><constant name="struts.multipart.saveDir" value="E:\"></constant>    <package name="default" namespace="/" extends="struts-default">        <action name="*_*" class="com.lsw.struts2_upload.actions.{1}Action" method="{2}">            <!-- 配置保存路径 -->            <param name="savePath">/uploadFile</param>            <result name="success">/WEB-INF/pages/success.jsp</result>            <result name="error">/error.jsp</result>        </action>    </package></struts>

2.index.jsp中创建表单(注意红色字体)

      <form action="Upload_upload" method="post" enctype="multipart/form-data">
            文件：<input type="file" name="file">
            <input type="submit" value="上传">
    </form>

3.action类(UploadAction)package com.lsw.struts2_upload.actions;

import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;@SuppressWarnings("serial")public class UploadAction extends ActionSupport{    private File file;//要上传的表单元素的name属性值    private String fileContentType;//上传文件的类型    private String fileFileName;//上传文件的名称    private String savePath;//用来接受依赖注入的文件保存路径        public String upload(){        FileOutputStream fos=null;        FileInputStream  fis=null;                        try {            fos=new FileOutputStream(getSavePath()+"\\"+getFileFileName());            fis=new FileInputStream(file);            byte[] buffer=new byte[1024];            int len=0;            while((len=fis.read(buffer))>0){                fos.write(buffer,0,len);            }            fos.flush();        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }finally{            if(fis!=null){                try {                    fis.close();                } catch (IOException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }            if(fos!=null){                try {                    fos.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }        return "success";            }    public File getFile() {        return file;    }    public void setFile(File file) {        this.file = file;    }    public String getFileContentType() {        return fileContentType;    }    public void setFileContentType(String fileContentType) {        this.fileContentType = fileContentType;    }    public String getFileFileName() {        return fileFileName;    }    public void setFileFileName(String fileFileName) {        this.fileFileName = fileFileName;    }    public String getSavePath() {        return ServletActionContext.getServletContext().getRealPath(savePath);    }    public void setSavePath(String savePath) {        this.savePath = savePath;    }}

ServletActionContext.getServletContext().getRealPath(savePath)

：web容器中对于路径都是获取发布项目当前Root下的路径 也就是/跟路径 而非磁盘上任意路径。
ServletActionContext.getServletContext().getRealPath("/files");
获取的是你项目所在的路径。