STRUTS2 Basic Learning (vi)-uploading and downloading of documents
Last Update:2016-05-11
Source: Internet
Author: User
<span id="Label3"></p>I. Uploading of documents 1. Single File upload<p><p>Struts2 uses interceptors to complete file uploads, and the underlying use of FileUpload open source Components.</p></p> <p><p>Client Considerations:</p></p> <p><p>(1) method= "<strong>post</strong>"</p></p> <p><p>(2) enctype= "<strong>multipart/form-data</strong>"</p></p> <p><p>(3) <intput type= "<strong>file</strong>" Name= "photo" ></p></p> <p><p></p></p> <p><p>When an action writes a file upload, you need to define three Properties.</p></p> <p><p>(1) file Type filename, The property name matches the name attribute of file in the Form.</p></p> <p><p>(2) string type, Property name: Name Property name + FileName Eg:photofilename.</p></p> <p><p>(3) string type, Property name: Name Property name + ContentType Eg:photocontenttype.</p></p> <p><p>finally, the GetXXX and Setxxx methods are provided for the above three attribute Names. The file is then copied via the Fileutils copyfile method, which uploads the file to the Server.</p></p> <p><p></p></p> <p><p>index.jsp</p></p> <pre><span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:form</span></span><span style="color: #ff0000"><span style="color: #ff0000">Action</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "uploadone"</span></span><span style="color: #ff0000"><span style="color: #ff0000">Method</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "post"</span></span><span style="color: #ff0000"><span style="color: #ff0000">enctype</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "multipart/form-data"</span></span><span style="color: #0000ff"><span style="color: #0000ff">></span></span> <span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:textfield</span></span><span style="color: #ff0000"><span style="color: #ff0000">name</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "username"</span></span><span style="color: #ff0000"><span style="color: #ff0000">label</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "user name"</span></span><span style="color: #0000ff"><span style="color: #0000ff">/></span></span> <span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:file</span></span><span style="color: #ff0000"><span style="color: #ff0000">name</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "photo"</span></span><span style="color: #ff0000"><span style="color: #ff0000">label</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "photo"</span></span><span style="color: #0000ff"><span style="color: #0000ff">/></span></span> <span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:submit</span></span><span style="color: #ff0000"><span style="color: #ff0000">value</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "upload"</span></span><span style="color: #0000ff"><span style="color: #0000ff">/></span></span> <span style="color: #0000ff"><span style="color: #0000ff"></</span></span><span style="color: #800000"><span style="color: #800000">S:form</span></span><span style="color: #0000ff"><span style="color: #0000ff">></span></span></pre><p><p>Uploadaction.java</p></p><pre class="brush: java; auto-links: true; collapse: false; first-line: 1; gutter: true; html-script: false; light: false; ruler: false; smart-tabs: true; tab-size: 4; toolbar: true;">public class Uploadaction extends Actionsupport{private string username;private File photo;private string photofilename ;//upload file name private string photocontenttype;//the MIME type of uploaded files public string Uploadone () throws ioexception{ System.out.println ("username =" + username + "\nphotoname =" + photofilename + "\nphotocontenttype =" + photocontenttype );//upload string storedir = Servletactioncontext.getservletcontext (). getrealpath ("/upload"); Fileutils.copyfile (photo,new File (storedir,photofilename)); return SUCCESS;} Public String getphotofilename () {return photofilename;} public void Setphotofilename (String Photofilename) {this.photofilename = photofilename;} Public String getphotocontenttype () {return photocontenttype;} public void Setphotocontenttype (String Photocontenttype) {this.photocontenttype = photocontenttype;} Public String getusername () {return username;} public void Setusername (String Username) {this.username = username;} Public File Getphoto () {return photo;} public void Setphoto (File photo) {this.photo = photo;}} </pre><p><p>Results:</p></p><p><p></p></p><p><p></p></p>2. Problems with file uploads<p><p>The total file upload size by default is 2M, if more than 2M, the program will report an exception, you can use <s:actionError> to view specific Information.</p></p><p><p><strong>(1) fix the total size setting, find the constant</strong></p></p><p><p>Struts.multipart.parser=jakarta default File Upload parser, which is the FileUpload component<br>Temporary file storage directory for struts.multipart.savedir= file upload<br>struts.multipart.maxsize=2097152 file Upload maximum value (total size), default is 2M<br>Set constants in Struts.xml to modify the default total size of file uploads</p></p><pre class="brush: xml; auto-links: true; collapse: false; first-line: 1; gutter: true; html-script: false; light: false; ruler: false; smart-tabs: true; tab-size: 4; toolbar: true;"><pre class="brush: xml; auto-links: true; collapse: false; first-line: 1; gutter: true; html-script: false; light: false; ruler: false; smart-tabs: true; tab-size: 4; toolbar: true;"><!--configure the size of the upload file--><constant name= "struts.multipart.maxSize" value= "5000000"/></pre></pre><p><p></p></p><p><p><strong>(2) You can also configure the interceptor to set up file upload</strong></p></p><pre class="brush: xml; auto-links: true; collapse: false; first-line: 1; gutter: true; html-script: false; light: false; ruler: false; smart-tabs: true; tab-size: 4; toolbar: true;"><pre class="brush: xml; auto-links: true; collapse: false; first-line: 1; gutter: true; html-script: false; light: false; ruler: false; smart-tabs: true; tab-size: 4; toolbar: true;"><action name= "uploadone" class= "com.kiwi.action.UploadAction" method= "uploadone" ><interceptor-ref name= " FileUpload "><!--configuration allows uploading of file types, multiple with", "separating--><param name=" allowedtypes ">image/bmp,image/png,image/gif, Image/jpeg,image/jpg,image/x-png,image/pjpeg</param><!--configure the file size allowed to upload, per Byte--><param name= " MaximumSize ">102400</param></interceptor-ref><interceptor-ref name=" DefaultStack "/>< Result Name= "success" >/success.jsp</result></action></pre></pre><p><p></p></p><p><p><strong>(3) Modify the resource file information that displays the error message</strong></p></p><p><p>The first step: create a new resource file such as message_zh_cn.properties, placed under SRC to add the following information in the resource file:</p></p><p><p>Struts.messages.error.uploading= upload error: {0}</p></p><p><p>struts.messages.error.file.too.large= upload file is too large: {0} "{1}" "{2}" {3}</p></p><p><p>struts.messages.error.content.type.not.allowed= upload file type not allowed: {0} "{1}" "{2}" {3}</p></p><p><p>struts.messages.error.file.extension.not.allowed= upload file suffix: {0} ' {1} ' ' {2} ' {3}</p></p><p><p>Step two: Load the resource file in the Struts.xml file</p></p><pre class="brush: xml; auto-links: true; collapse: false; first-line: 1; gutter: true; html-script: false; light: false; ruler: false; smart-tabs: true; tab-size: 4; toolbar: true;"><pre class="brush: xml; auto-links: true; collapse: false; first-line: 1; gutter: true; html-script: false; light: false; ruler: false; smart-tabs: true; tab-size: 4; toolbar: true;"><constant name= "struts.custom.i18n.resources" value= "message"/></pre></pre><p><p></p></p>3. Multi-file Upload<p><p>On the JSP page to provide multiple sets of file upload input box, select multiple file Upload.</p></p><p><p>index.jsp</p></p> <pre><span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:form</span></span><span style="color: #ff0000"><span style="color: #ff0000">Action</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "uploadone"</span></span><span style="color: #ff0000"><span style="color: #ff0000">Method</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "post"</span></span><span style="color: #ff0000"><span style="color: #ff0000">enctype</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "multipart/form-data"</span></span><span style="color: #0000ff"><span style="color: #0000ff">></span></span> <span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:textfield</span></span><span style="color: #ff0000"><span style="color: #ff0000">name</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "username"</span></span><span style="color: #ff0000"><span style="color: #ff0000">label</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "user name"</span></span><span style="color: #0000ff"><span style="color: #0000ff">/></span></span> <span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:file</span></span><span style="color: #ff0000"><span style="color: #ff0000">name</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "photo"</span></span><span style="color: #ff0000"><span style="color: #ff0000">label</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "photo 1"</span></span><span style="color: #0000ff"><span style="color: #0000ff">/></span></span> <span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:file</span></span><span style="color: #ff0000"><span style="color: #ff0000">name</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "photo"</span></span><span style="color: #ff0000"><span style="color: #ff0000">label</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "photo 2"</span></span><span style="color: #0000ff"><span style="color: #0000ff">/></span></span> <span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:file</span></span><span style="color: #ff0000"><span style="color: #ff0000">name</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "photo"</span></span><span style="color: #ff0000"><span style="color: #ff0000">label</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "photo 3"</span></span><span style="color: #0000ff"><span style="color: #0000ff">/></span></span> <span style="color: #0000ff"><span style="color: #0000ff"><</span></span><span style="color: #800000"><span style="color: #800000">S:submit</span></span><span style="color: #ff0000"><span style="color: #ff0000">value</span></span><span style="color: #0000ff"><span style="color: #0000ff">= "upload"</span></span><span style="color: #0000ff"><span style="color: #0000ff">/></span></span> <span style="color: #0000ff"><span style="color: #0000ff"></</span></span><span style="color: #800000"><span style="color: #800000">S:form</span></span><span style="color: #0000ff"><span style="color: #0000ff">></span></span></pre><p><p>Uploadaction.java</p></p><pre class="brush: java; auto-links: true; collapse: false; first-line: 1; gutter: true; html-script: false; light: false; ruler: false; smart-tabs: true; tab-size: 4; toolbar: true;">public class UploadAction2 extends Actionsupport{private String username;private file[] photo;private string[] photofilename;//uploaded file name private string[] photocontenttype;//uploaded files MIME type public String uploadone () throws ioexception{/ /upload string storedir = Servletactioncontext.getservletcontext (). getrealpath ("/upload"); If (photo! = null && Photo.length > 0) {for (int i = 0;i < Photo.length;i++) {fileutils.copyfile (photo[i],new File (storedir, photofilename[i]));}} Return SUCCESS;} Public String getusername () {return username;} public void Setusername (String Username) {this.username = username;} Public file[] Getphoto () {return photo;} public void Setphoto (file[] photo) {this.photo = photo;} Public string[] getphotofilename () {return photofilename;} public void Setphotofilename (string[] Photofilename) {this.photofilename = photofilename;} Public string[] getphotocontenttype () {return photocontenttype;} public void Setphotocontenttype (string[] Photocontenttype) {this.photocontenttype = Photocontenttype;}} </pre><p><p> Struts2 Basic Learning (vi)-uploading and downloading of files </p> </p></span>
