1、单文件上传
单文件上传步骤:
1)创建上传jsp页面
文件上传的表单提交方式必须是POST方式,编码类型:enctype="multipart/form-data",默认是 application/x-www-form-urlencoded,比如:
1 <form action="${pageContext.servletContext.contextPath}/uploadAction.action" enctype="multipart/form-data" method="post">
2)创建处理文件上传Action类
- 在Action类中声明相关属性:
- 要声明与页面中表单name属性同名的属性,同名的属性的类型是File类型,该属性用来保存临时文件;
- 要声明[同名的属性]ContentType属性,类型是String类型,该属性表示上传文件的类型;
- 要声明[同名的属性]FileName属性,类型是String类型,该文件表示要上传的文件;
- 给所有属性提供get和set方法。
- 在Action类中提供处理上传的方法:
- 获取要保存文件的位置;
- 在目标文件夹内,创建一个与上传文件同名的文件;
- 通过FileUtils工具类提供copyFile()方法,将临时文件内容拷贝到目标文件夹下的那个同名的文件;
- 调用保存临时文件的属性的delete()方法删除临时文件(也就是File类型属性的delete方法)。
3)配置struts.
可以在struts.
1 <interceptor-ref name="defaultStack">2 <!--配置上传文件的大小,这里配置的是上传文件的单个大小-->3 <param name="fileUpload.maximumSize">20971520</param> 4 <!-- 配置上传文件允许的类型-->5 <param name="fileUpload.allowedTypes">text/plain,application/msword</param>6 <!-- 配置上传文件的扩展名-->7 <param name="fileUpload.allowedExtensions">.txt,.doc</param>8 </interceptor-ref>
允许的类型(allowedTypes)和允许的扩展名(allowedExtensions)必须保持一致。
单文件上传示例:
1)创建jsp页面
1 <body>2 <form action="${pageContext.servletContext.contextPath}/uploadAction.action" enctype="multipart/form-data" method="post">3 上传文件:<input type="file" name="upload">4 <input type="submit" value="上传">5 </form>6 </body>
2)创建Action类
1 public class UploadAction extends ActionSupport { 2 private File upload; 3 private String uploadContentType; 4 private String uploadFileName; 5 6 public File getUpload() { 7 return upload; 8 } 9 10 public void setUpload(File upload) {11 this.upload = upload;12 }13 14 public String getUploadContentType() {15 return uploadContentType;16 }17 18 public void setUploadContentType(String uploadContentType) {19 this.uploadContentType = uploadContentType;20 }21 22 public String getUploadFileName() {23 return uploadFileName;24 }25 26 public void setUploadFileName(String uploadFileName) {27 this.uploadFileName = uploadFileName;28 }29 30 @Override31 public String execute() throws Exception {32 ServletContext sc = ServletActionContext.getServletContext();33 //获取要保存文件的位置34 String path = sc.getRealPath("/upload");35 //创建一个与上传文件同名的文件36 File file = new File(path, uploadFileName);37 //将临时文件内容拷贝到目标文件夹下的那个同名的文件38 FileUtils.copyFile(upload, file);39 //删除临时文件40 upload.delete();41 return SUCCESS;42 }43 }
3)配置struts.
1 <struts> 2 <constant name="struts.devMode" value="true" /> 3 <constant name="struts.multipart.maxSize" value="200000000"/> 4 <package name="default" namespace="/" extends="struts-default"> 5 <action name="uploadAction" class="com.sunny.action.UploadAction"> 6 <result>/success.jsp</result> 7 <result name="input">/error.jsp</result> 8 <interceptor-ref name="defaultStack"> 9 <param name="fileUpload.maximumSize">20971520</param>10 <param name="fileUpload.allowedTypes">text/plain,application/msword</param>11 <param name="fileUpload.allowedExtensions">.txt,.doc</param>12 </interceptor-ref>13 </action>14 </package>15 </struts>
4)上传文件界面
5)上传成功后会跳转到success.jsp页面
6)项目下的upload文件夹下会有上传的文件
2、多文件上传
多文件上传的所有流程与单文件上传一致,但是需要注意的是:
- 在页面中,虽然是多文件上传,但是页面中表单的name属性的值必须保持一致;
- 在Action类中声明的相关属性,类型改成数组或者集合;
- 在业务方法中,相关处理流程改成单文件上传的循环。
单文件上传示例:
1)创建jsp页面
1 <body>2 <form action="${pageContext.servletContext.contextPath}/uploadAction.action" enctype="multipart/form-data" method="post">3 上传文件:<input type="file" name="upload"><br>4 上传文件:<input type="file" name="upload"><br>5 上传文件:<input type="file" name="upload"><br>6 上传文件:<input type="file" name="upload"><br>7 <input type="submit" value="上传">8 </form>9 </body>
2)创建Action类
1 public class UploadAction extends ActionSupport { 2 private File[] upload; 3 private String[] uploadContentType; 4 private String[] uploadFileName; 5 6 public File[] getUpload() { 7 return upload; 8 } 9 10 public void setUpload(File[] upload) {11 this.upload = upload;12 }13 14 public String[] getUploadContentType() {15 return uploadContentType;16 }17 18 public void setUploadContentType(String[] uploadContentType) {19 this.uploadContentType = uploadContentType;20 }21 22 public String[] getUploadFileName() {23 return uploadFileName;24 }25 26 public void setUploadFileName(String[] uploadFileName) {27 this.uploadFileName = uploadFileName;28 }29 30 @Override31 public String execute() throws Exception {32 ServletContext sc = ServletActionContext.getServletContext();33 //获取要保存文件的位置34 String path = sc.getRealPath("/upload");35 //创建一个与上传文件同名的文件36 for (int i = 0; i < upload.length; i++) {37 File file = new File(path, uploadFileName[i]);38 //将临时文件内容拷贝到目标文件夹下的那个同名的文件39 FileUtils.copyFile(upload[i], file);40 //删除临时文件41 upload[i].delete();42 }43 return SUCCESS;44 }45 }
3)配置struts.
1 <struts> 2 <constant name="struts.devMode" value="true" /> 3 <constant name="struts.multipart.maxSize" value="200000000"/> 4 <package name="default" namespace="/" extends="struts-default"> 5 <action name="uploadAction" class="com.sunny.action.UploadAction"> 6 <result>/success.jsp</result> 7 <result name="input">/error.jsp</result> 8 <interceptor-ref name="defaultStack"> 9 <param name="fileUpload.maximumSize">20971520</param>10 <param name="fileUpload.allowedTypes">text/plain,application/msword</param>11 <param name="fileUpload.allowedExtensions">.txt,.doc</param>12 </interceptor-ref>13 </action>14 </package>15 </struts>
4)上传文件界面
5)上传成功后会跳转到success.jsp页面
6)项目下的upload文件夹下会有上传的文件
原标题:Struts2学习笔记(十一)——文件上传下载
关键词:Struts