Struts2 多文件上传、限制文件大小、更改错误提示--文件下载

程序员文章站 2022-07-14 08:16:16

...

好记性不如赖笔头…………

1、导入须要使用的jar包

2、创建jsp文件，代码如下

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!--导入Struts2标签-->
<%@ taglib uri="/struts-tags" prefix="s" %>
<%
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%>">

    <title>文件上传</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">
  </head>

  <body>
  <h1>文件上传</h1>
    <s:form action="fileUpload.action" enctype="multipart/form-data">
        <s:file name="fileName" label="文件1"></s:file>
        <s:file name="fileName" label="文件2"></s:file> 
        <s:submit value="上传"></s:submit>
    </s:form>
    <hr/>
    <h1>文件下载</h1>
    <a href="${pageContext.request.contextPath }/fileDownload.action">下载图片</a>
  </body>
</html>

3、创建FileUploadAction类,并实现ActionSupport，具体代码如下：

package com.ckinghan.web.action;

import java.io.File;
import java.io.IOException;
import java.util.UUID;

import javax.servlet.ServletContext;

import org.apache.commons.io.FileUtils;
import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class FileUploadAction extends ActionSupport {

    /**
     * 支持序列化
     */
    private static final long serialVersionUID = 1L;

    //上传文件数组
    private File[] fileName;

    //上传文件 的文件名
    private String[] fileNameFileName;

    //上传文件的MIME类型
    private String[] fileNameContentType;



    public File[] getFileName() {
        return fileName;
    }



    public void setFileName(File[] fileName) {
        this.fileName = fileName;
    }



    public String[] getFileNameFileName() {
        return fileNameFileName;
    }



    public void setFileNameFileName(String[] fileNameFileName) {
        this.fileNameFileName = fileNameFileName;
    }



    public String[] getFileNameContentType() {
        return fileNameContentType;
    }



    public void setFileNameContentType(String[] fileNameContentType) {
        this.fileNameContentType = fileNameContentType;
    }



    public String fileUpload(){
        //如果上传文件为空，则直接结束
        if(fileName == null || fileName.length == 0){
            return null;
        }
        //获取ServletContext 
        ServletContext context = ServletActionContext.getServletContext();
        //通过ServletContext 获取目录的真实路径，定位路径为：项目目录下，与WEB-INF同级，可以*更改
        String fileUrl = context.getRealPath("files");
        //创建文件，如果文件夹不存在，则创建
        File file = new File(fileUrl);
        if(!file.exists()){
            file.mkdirs();
        }

        //将文件复制到指定路径 下，会留下缓存文件，不建议使用
        /**
        try {
            for (int i = 0; i < fileName.length; i++) {
                FileUtils.copyFile(fileName[i],new File(file, UUID.randomUUID().toString()+fileNameFileName[i].substring(fileNameFileName[i].lastIndexOf("."), fileNameFileName[i].length())) );
            }
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
        */

        //将文件循环剪贴到指定位置并重命名，不会有缓存文件留下
        for(int i = 0; i <fileName.length;i++){
            fileName[i].renameTo(new File(file, UUID.randomUUID().toString()+fileNameFileName[i].substring(fileNameFileName[i].lastIndexOf("."), fileNameFileName[i].length())));
        }
        return null;
    }
}

4、创建文件下载 FileDownloadAction，继承ActionSupport类，具体内容如下：

package com.ckinghan.web.action;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class FileDownloadAction extends ActionSupport {

    //注意：此处命名不能使用in，会出问题
    private InputStream inputStream;

    private String fileName;

    public InputStream getInputStream() {
        return inputStream;
    }

    public void setInputStream(InputStream inputStream) {
        this.inputStream = inputStream;
    }

    public void setFileName(String fileName) {
        this.fileName = fileName;
    }

    public InputStream getInputStream() {
        return inputStream;
    }

    public String fileDownload() throws FileNotFoundException{
        //获取图片路径
        String fileUrl = ServletActionContext.getServletContext().getRealPath("/files/33e765f4-cb37-4d3a-b9ae-b09240fc6519.jpg");
        //初始化流
        inputStream = new FileInputStream(fileUrl);

        fileName = "下载的相片.png";

        return SUCCESS;
    }
}

5、创建替换错误提示的FileUploadAction-messages.properties文件，与FileUploadAction文件处理于同一目录下，具体内容如下：

struts.messages.error.content.type.not.allowed=\u4E0A\u4F20\u6587\u4EF6\u4EC5\u652F\u6301\u56FE\u7247\u683C\u5F0F\:
struts.messages.error.file.extension.not.allowed=\u4EC5\u652F\u6301\u4EE5\u4E0B\u6269\u5C55\u540D\u6587\u4EF6\u7684\u4E0A\u4F20\uFF1Apng,jpeg,pjpeg,gif,bmp,jpg

效果图片如下：

Struts2 多文件上传、限制文件大小、更改错误提示--文件下载

此文件中替换内容的原始文件路径为：struts2-core-2.3.15.3.jar包下的org/apache/struts2/struts-messages.properties，文件的具体内容如下，可以参考将所有的错误替换为中文提示：

#
# $Id: struts-messages.properties 1379458 2012-08-31 14:06:00Z lukaszlenart $
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#  http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#
struts.messages.invalid.token=The form has already been processed or no token was supplied, please try again.
struts.internal.invalid.token=Form token {0} does not match the session token {1}.

struts.messages.bypass.request=Bypassing {0}/{1}
struts.messages.current.file=File {0} {1} {2} {3}
struts.messages.invalid.file=Could not find a Filename for {0}. Verify that a valid file was submitted.
struts.messages.invalid.content.type=Could not find a Content-Type for {0}. Verify that a valid file was submitted.
struts.messages.removing.file=Removing file {0} {1}
struts.messages.error.uploading=Error uploading: {0}
struts.messages.error.file.too.large=The file is to large to be uploaded: {0} "{1}" "{2}" {3}
struts.messages.error.content.type.not.allowed=Content-Type not allowed: {0} "{1}" "{2}" {3}
struts.messages.error.file.extension.not.allowed=File extension not allowed: {0} "{1}" "{2}" {3}

# dedicated messages used to handle various problems with file upload - check {@link JakartaMultiPartRequest#parse(HttpServletRequest, String)}
struts.messages.upload.error.SizeLimitExceededException=Request exceeded allowed size limit! Max size allowed is: {0} but request was: {1}!
struts.messages.upload.error.IOException=Error uploading: {0}!

devmode.notification=Developer Notification (set struts.devMode to false to disable this message):\n{0}

struts.exception.missing-package-action.with-context = There is no Action mapped for namespace [{0}] and action name [{1}] associated with context path [{2}].

6、创建Struts.xml配置文件在src目录下，具体配置信息如下：

<?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>

    <!-- 开启调试模式 -->
    <constant name="struts.devMode" value="true"/>
    <!-- 限制上传文件的大小,默认最大上传2M，这里改为了5M-->
    <constant name="struts.multipart.maxSize" value="5242880"/>
    <!-- 错误提示替换为中文，原配置文件路径为：struts2-core-2.3.15.3.jar/org/apache/struts2/struts-messages.properties -->
    <constant name="struts.custom.i18n.resources" value="com.ckinghan.web.action.FileUploadAction-messages"/>
    <!-- 开启OGNL的静态方法调用  -->
    <constant name="struts.ognl.allowStaticMethodAccess" value="true"/>

    <package name="fileUpload" extends="struts-default">
        <action name="fileUpload" class="com.ckinghan.web.action.FileUploadAction" method="fileUpload">
            <!-- 拦截器  -->
            <interceptor-ref name="defaultStack">
                <!-- 注入可以上传的文件类型 
                <param name="fileUpload.allowedTypes">image/bmp,image/png,image/gif,image/jpeg,image/jpg</param>-->
                <!-- 注入上传文件的扩展名-->
                <param name="fileUpload.allowedExtensions">.png,.jpeg,.pjpeg,.gif,.bmp,.jpg</param>

            </interceptor-ref>
            <result name="input" >/index.jsp</result>
        </action>

        <!-- 图片下载 -->
        <action name="fileDownload" class="com.ckinghan.web.action.FileDownloadAction" method="fileDownload">
            <!-- 返回的类型为stream流 ，下面注入参数的java类为：Struts2-core-2.3.15.3.jar包下的org.apache.struts2.dispatcher.StreamResult-->
            <result type="stream">
                <!-- 注入返回的表头：contentType =application/x-download  -->
                <param name="contentType">application/x-download</param>
                <!-- 注入参数contentDisposition，返回的类型为附件下载，使用OGNL将程序给定的文件名写入命名给图片,使用URLEncoder防止中文乱码 -->
                <param name="contentDisposition">attachment;filename=${@aaa@qq.com(fileName,"UTF-8")}</param>
                <!-- 将指定的动作类中的inputStream注入到inputName中，实现下载 -->
                <param name="inputName">inputStream</param>
            </result>
        </action>
    </package>

</struts>