java struts2入门学习实例－－使用struts2快速实现多个文件上传

一、错误提示信息配置

昨天说到更改默认错误配置信息，我测试很多遍，一直都不对。下面贴出来，待以后有好方法了再补充吧。

首先新建一个properties文件，这里命名为testupload.properties,内容为：

struts.messages.error.file.too.large=\u6587\u4EF6\u592A\u5927{0} "{1}" "{2}" {3}

struts.messages.error.content.type.not.allowed=\u6587\u4EF6\u7C7B\u578B\u4E0D\u5141\u8BB8! {0} "{1}" "{2}" {3}

struts.messages.error.file.extension.not.allowed=\u4E0D\u5141\u8BB8\u7684\u6269\u5C55\u540D! {0} "{1}" "{2}" {3}

这里将默认提示信息改为中文的。upload.xml中内容如下：

<?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>

    <!-- 对上传文件总大小进行设置 -->

    <constant name="struts.multipart.maxSize" value="20971520"></constant>

    <!-- 错误信息提示 -->

    <constant name="struts.custom.i18n.resources" value="testupload"/>

    <package name="upload" extends="struts-default">

        <action name="UploadAction" class="action.UploadAction" method="uploadMethod">

            <result name="success" type="dispatcher">

                /WEB-INF/upload_success.jsp

            </result>

            <result name="input" type="dispatcher">

                upload.jsp

            </result>

            <!-- 对系统的拦截器进行设置 -->

            <interceptor-ref name="fileUpload">

                <!-- 对单个上传文件的大小进行设置,5M -->

                <param name="maximumSize">5242880</param>

                <!-- 对允许的文件扩展名进行设置,这里以英文逗号隔开 -->

                <param name="allowedExtensions">.txt,.xml</param>

                <!-- 对允许的文件类型进行设置，这里以英文逗号进行隔开 -->

                <param name="allowedTypes">text/plain,text/xml</param>

            </interceptor-ref>

            <!-- 显示引用默认的拦截器 -->

            <interceptor-ref name="defaultStack"></interceptor-ref>

        </action>

    </package>

</struts>

二、多个文件上传

只需要更改upload.jsp中的部分内容即可：

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<%@ taglib uri="/struts-tags" prefix="s"  %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<title>Insert title here</title>

</head>

<body>

    <s:form action="UploadAction" enctype="multipart/form-data" method="POST">

        <s:textfield label="上传用户" name="username"/>

        <s:file label="上传文件" name="upload" />

        <s:file label="上传文件" name="upload" />

         <s:file label="上传文件" name="upload" />

        <s:submit value="提交"/>

    </s:form>

</body>

</html>

结果如下所示：

也可以将UploadAction.java中的file改为数组类型的，如下所示：

package action;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.OutputStream;

import javax.servlet.ServletContext;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

/**

 * @ClassName: UploadAction

 * @Description: 文件上传

 * @author: amosli

 * @email:amosli@infomorrow.com

 * @date Jan 14, 2014 1:50:28 AM

 */

public class UploadAction extends ActionSupport {

    private static final long serialVersionUID = -8920466592471253212L;

    private String username;// 用户名

    private String[] uploadContentType;// 上传文件的类型,(Fileupload拦截器传入的参数)

    private File[] upload;// 上传的文件,(Fileupload拦截器传入的参数)

    private String[] uploadFileName;// 上传文件的真实文件名，(Fileupload拦截器传入的参数)

    public void setUsername(String username) {

        this.username = username;

    }

    public String[] getUploadContentType() {

        return uploadContentType;

    }

    public void setUploadContentType(String[] uploadContentType) {

        this.uploadContentType = uploadContentType;

    }

    public File[] getUpload() {

        return upload;

    }

    public void setUpload(File[] upload) {

        this.upload = upload;

    }

    public String[] getUploadFileName() {

        return uploadFileName;

    }

    public void setUploadFileName(String[] uploadFileName) {

        this.uploadFileName = uploadFileName;

    }

    public String getUsername() {

        return username;

    }

    public String uploadMethod() throws Exception {

        ServletContext context = ServletActionContext.getServletContext();

        String real_path = context.getRealPath("/WEB-INF/upload/");

        for (int i = 0; i < upload.length; i++) {

            InputStream inputStream = new FileInputStream(upload[i]);

            OutputStream outputStream = new FileOutputStream(real_path + "/" + uploadFileName);

            byte[] b = new byte[1024];

            int len = 0;

            while ((len = inputStream.read(b)) > 0) {

                outputStream.write(b, 0, len);

            }

            // 关闭流

            inputStream.close();

            outputStream.close();

            // 删除tmp文件,最好是用tyrcatch finally进行删除

            // upload[i].delete();

        }

        return SUCCESS;

    }

}

这里没有立马删除是想做个演示，查看一下缓存文件空间生成了几个。

首先，将项目打包，生成war包，这里我用的是mvn package打的包。

其次，将tomcat启动，将成生的war包拷到webapp目录下。

最后，在浏览器演示多个文件上传。

演示结果如下图所示：

1、打开浏览器，上传a.txt,b.txt,c.txt三个文件

2、点击提交后，跳转到成功提示页面

3.查看相对应的文件目录，这里没有删除缓存，所以可以看到三个缓存文件

三、指定文件上传的路径

如何通过配置文件，手动指定文件的上传目录？

首先，在upload.xml中action标签中指定参数名为uploadPath,赋值为/home/amosli/develop/struts2_learn/

<action name="UploadAction" class="action.UploadAction" method="uploadMethod">

            <param name="uploadPath">/home/amosli/develop/struts2_learn/</param>

.................

全部的upload.xml文件为：

<?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>

    <!-- 对上传文件总大小进行设置 -->

    <constant name="struts.multipart.maxSize" value="20971520"></constant>

    <!-- 错误信息提示 -->

    <constant name="struts.custom.i18n.resources" value="testupload" />

    <package name="upload" extends="struts-default">

        <action name="UploadAction" class="action.UploadAction" method="uploadMethod">

            <param name="uploadPath">/home/amosli/develop/struts2_learn/</param>

            <result name="success" type="dispatcher">

                /WEB-INF/upload_success.jsp

            </result>

            <result name="input" type="dispatcher">

                upload.jsp

            </result>

            <!-- 对系统的拦截器进行设置 -->

            <interceptor-ref name="fileUpload">

                <!-- 对单个上传文件的大小进行设置,5M -->

                <param name="maximumSize">5242880</param>

                <!-- 对允许的文件扩展名进行设置,这里以英文逗号隔开 -->

                <param name="allowedExtensions">.txt,.xml</param>

                <!-- 对允许的文件类型进行设置，这里以英文逗号进行隔开 -->

                <param name="allowedTypes">text/plain,text/xml</param>

            </interceptor-ref>

            <!-- 显示引用默认的拦截器 -->

            <interceptor-ref name="defaultStack"></interceptor-ref>

        </action>

    </package>

</struts>

其次，在UploadAction.java中新建一个变量uploadPath,为其设置set方法。同时在uploadMethod方法中将目标文件夹改为uploadPath.

即,UploadAction.java为：

package action;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.OutputStream;

import com.opensymphony.xwork2.ActionSupport;

/**

 * @ClassName: UploadAction

 * @Description: 文件上传

 * @author: amosli

 * @email:amosli@infomorrow.com

 * @date Jan 14, 2014 1:50:28 AM

 */

public class UploadAction extends ActionSupport {

    private static final long serialVersionUID = -8920466592471253212L;

    private String username;// 用户名

    private String[] uploadContentType;// 上传文件的类型,(Fileupload拦截器传入的参数)

    private File[] upload;// 上传的文件,(Fileupload拦截器传入的参数)

    private String[] uploadFileName;// 上传文件的真实文件名，(Fileupload拦截器传入的参数)

    private String uploadPath;

    public void setUploadPath(String uploadPath) {

        this.uploadPath = uploadPath;

    }

    public void setUsername(String username) {

        this.username = username;

    }

    public String[] getUploadContentType() {

        return uploadContentType;

    }

    public void setUploadContentType(String[] uploadContentType) {

        this.uploadContentType = uploadContentType;

    }

    public File[] getUpload() {

        return upload;

    }

    public void setUpload(File[] upload) {

        this.upload = upload;

    }

    public String[] getUploadFileName() {

        return uploadFileName;

    }

    public void setUploadFileName(String[] uploadFileName) {

        this.uploadFileName = uploadFileName;

    }

    public String getUsername() {

        return username;

    }

    public String uploadMethod() throws Exception {

//        ServletContext context = ServletActionContext.getServletContext();

//        String real_path = context.getRealPath("/WEB-INF/upload/");

        for (int i = 0; i < upload.length; i++) {

            InputStream inputStream = new FileInputStream(upload[i]);

            OutputStream outputStream = new FileOutputStream(uploadPath + "/" + uploadFileName[i]);

            byte[] b = new byte[1024];

            int len = 0;

            while ((len = inputStream.read(b)) > 0) {

                outputStream.write(b, 0, len);

            }

            // 关闭流

            inputStream.close();

            outputStream.close();

            // 删除tmp文件,最好是用tyrcatch finally进行删除

            // upload[i].delete();

        }

        return SUCCESS;

    }

}

最后，运行效果如下：

本文源码:https://github.com/amosli/strut2_learn