26.struts2_文件的上传

来源：互联网发布：如何将相同的数据合并编辑：程序博客网时间：2024/05/22 03:14

一、准备工作

表单准备：将 HTML表单 enctype属性设置为 multipart/form-data

表单需要使用 method为post的方式

添加<input type=“file”>字段

二、struts2对文件上传的支持

框架中，FileUpload拦截器和Jakarta Commons FileUpload组件可以完成文件的上传。

步骤：

1.在对应Action建立三个属性

private File [fileFieldName]; //这个fileFieldName对应页面上<s:file name=""/> 的name属性

private String [fileFieldName]ContentType;

private String [fileFieldName]FileName;

UploadAction.java

public class UploadAction extends ActionSupport {/** *  */private static final long serialVersionUID = 1L;private File ppt;private String  pptContentType; private String pptFileName;private String pptDesc;public String getPptDesc() {return pptDesc;}public void setPptDesc(String pptDesc) {this.pptDesc = pptDesc;}public File getPpt() {return ppt;}public void setPpt(File ppt) {this.ppt = ppt;}public String getPptContentType() {return pptContentType;}public void setPptContentType(String pptContentType) {this.pptContentType = pptContentType;}public String getPptFileName() {return pptFileName;}public void setPptFileName(String pptFileName) {this.pptFileName = pptFileName;}@Overridepublic String execute() throws Exception {System.out.println(ppt);System.out.println(pptContentType);System.out.println(pptFileName);System.out.println(pptDesc);//使用IO流进行上传ServletContext sac=ServletActionContext.getServletContext();String dir=sac.getRealPath("/files/"+pptFileName);System.out.println(dir);FileOutputStream out =new FileOutputStream(dir);FileInputStream in = new FileInputStream(ppt);byte[] buffer=new byte[1024];int len=0;while((len=in.read(buffer))!=-1){out.write(buffer,0,len);}out.close();in.close();return SUCCESS;}}

upload.jsp

<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><s:form action="testUpload" method="post" enctype="multipart/form-data"><s:file name="ppt" label="PPTFile"></s:file><s:textfield name="pptDesc" label="PPTDesc" ></s:textfield><s:submit></s:submit></s:form></body></html>

三、配置FileUploadInterceptor拦截器参数，限制上传,并给出提示

maximumSize (optional) - the maximum size (in bytes) that the interceptor will allow a file reference to be set on the action. Note, this isnot related to the various properties found in struts.properties. Default to approximately 2MB.//单个文件上传最大值
allowedTypes (optional) - a comma separated list of content types (ie: text/html) that the interceptor will allow a file reference to be set on the action. If none is specified allow all types to be uploaded.//允许的上传文件类型，多个使用【，】分隔
allowedExtensions (optional) - a comma separated list of file extensions (ie: .html) that the interceptor will allow a file reference to be set on the action. If none is specified allow all extensions to be uploaded.//允许上传文件的扩展名，逗号分隔

可以在国际化资源中定义如下消息

struts.messages.error.uploading - 文件上传出错
struts.messages.error.file.too.large - 超过大小
struts.messages.error.content.type.not.allowed - 文件内容类型不合法
struts.messages.error.file.extension.not.allowed - 文件扩展名不合法

添加错误提示后的struts.xml

<?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><!-- 配置国际化资源文件 --><constant name="struts.custom.i18n.resources" value="i18n"></constant><package name="default" namespace="/" extends="struts-default"><!-- 配置拦截器栈 --><interceptors><interceptor-stack name="hcx"><interceptor-ref name="defaultStack"><param name="fileUpload.maximumSize">2000</param><param name="fileUpload.allowedTypes">text/plain,text/xml</param><param name="fileUpload.allowedExtensions">txt,html</param></interceptor-ref></interceptor-stack></interceptors><!-- 使用拦截器栈 --><default-interceptor-ref name="hcx"/> <action name="testUpload" class="com.hcx.app.UploadAction"><result name="success">/success.jsp</result><result name="input">/upload.jsp</result></action></package></struts>

但是目前提示消息不完善，具体可以参考org.apache.struts2下的struts-messages.properties文件，下面是例子中的国际化文件

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}

注意： 在struts2的defaul.properties中有对上传文件总的大小限制，为2M。struts.multipart.maxSize=2097152。如果修改可以按照上述方式。

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