Struts2 文件上传

更详细的介绍参见：
http://www.blogjava.net/max/archive/2007/03/21/105124.html
所要用到的jar
commons-fileupload-1.2.1.jar
commons-io-1.3.2.jar
commons-logging-1.0.4.jar
commons-logging-1.1.1.jar
freemarker-2.3.13.jar
ognl-2.6.11.jar
struts2-core-2.1.6.jar
xwork-2.1.2.jar

如果是直接用SSH中的Strutsjar包记得删除Struts2-Spring-Plugin

否则系统会认为你spring的部分没有配置上对于仅使用struts的项目而言这个包不是多余而是不能有

Eclipse JEE编辑器不是那么的智能创建web工程没有加入Servlet的jar包需要自己手动添加

web.xml

<?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">


    <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>

struts配置

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
    <constant name="struts.devMode" value="true"></constant>
    <constant name="struts.action.extension" value="do,action"></constant>

    <package name="struts2" extends="struts-default" namespace="/">
        <action name="UploadAction_*" class="action.UploadAction"
            method="{1}">
            <result name="success">/upload.jsp</result>

        </action>
    </package>
</struts>

页面

<%@page contentType="text/html; charset=GBK" language="java"%>
<%@taglib prefix="s" uri="/struts-tags"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title>Struts 2 File Upload</title>
    </head>
    <body>
        <s:form action="UploadAction_uploadEssays.action" method="POST"
            enctype="multipart/form-data">
            <s:file name ="myFile" />
            <s:file name ="myFile" />
            <s:file name ="myFile" />
            <s:textfield name="caption" label="Caption" />
            <s:submit />
        </s:form>
    </body>
</html>

UploadAction

package action;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Date;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class UploadAction extends ActionSupport {
    private static final long serialVersionUID = 572146812454l;
    private static final int BUFFER_SIZE = 16 * 1024; // 这里的BUFFER_SIZE
                                                        // 表示一个数据缓冲区是16KB
    // 所以写出的文件最小是16KB

    private File[] myFile; //myFile就是用户准备上传的文件
    private String[] myFileContentType;
    private String[] myFileFileName; //用户上传文件的真实文件名
    //当然了 这里的属性命名是任意的
    //但是要保证和页面元素中的 name属性的值要匹配
    //比如 页面中input 的name是myFile 我这里就应该有 setMyFile  getMyFile
    //为了减少出错， 属性都用对应的名字好了
    //若文件对象的名字是xxx   文件类型就应是 xxxContentType  真实文件名则应是xxxFileName
   

    // private String caption;
    public File[] getMyFile() {
        return myFile;
    }

    public void setMyFile(File[] myFile) {
        this.myFile = myFile;
    }

    public String[] getMyFileContentType() {
        return myFileContentType;
    }

    public void setMyFileContentType(String[] myFileContentType) {
        this.myFileContentType = myFileContentType;
    }

    public String[] getMyFileFileName() {
        return myFileFileName;
    }

    public void setMyFileFileName(String[] myFileFileName) {
        this.myFileFileName = myFileFileName;
    }

    private static String getExtention(String fileName) {
        int pos = fileName.lastIndexOf(".");
        return fileName.substring(pos);
    }

   
   
   
    private static void copy(File src, File dst) {
        System.out.println("000000   src dst "+src.getPath()+"   "+dst.getPath());
        try {
            InputStream in = null;
            OutputStream out = null;
            try {
                in = new BufferedInputStream(new FileInputStream(src),
                        BUFFER_SIZE);
                out = new BufferedOutputStream(new FileOutputStream(dst),
                        BUFFER_SIZE);

                // 上传的最小文件不能小于 1 KB 否则会出现找不到文件的错误
                byte[] buffer = new byte[BUFFER_SIZE];
                while (in.read(buffer) > 0) {
                    out.write(buffer);
                }

            } finally {
                if (null != in) {
                    in.close();
                }
                if (null != out) {
                    out.close();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // 为了保证上传文件不会重名
    // 文件名以当前毫秒数保存
    private String saveFileName; // 以当前毫秒数为文件名

    public String uploadEssays() {
        for (int i = 0; i < myFile.length; i++) {
            saveFileName = new Date().getTime() + getExtention(myFileFileName[i]);
            // writeFile 就是以当前毫秒数为文件名的文件
            /*File writeFile = new File(ServletActionContext.getServletContext()
                    .getRealPath("/files")
                    + "/" + saveFileName);*/
            File writeFile=new File("D:/Workspaces8.6_J2EE/files/"+saveFileName);
            System.out.println("000000000   tmp "+myFile[i]);
            copy(myFile[i], writeFile);
        }
        return SUCCESS;
    }

}

！！！

(ServletActionContext.getServletContext().getRealPath("/files") 这里得到文件路径会因为操作系统不同而由变化
所以上传前线弄清楚到底位置在哪里或者自己写一个确定的绝对路径

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