雪山飛鵠

Struts2文件上傳

大家都知道struts2對(duì)文件上傳做了很好的封裝，使文件上傳不再那么恐怖。這里面struts2的文件上傳主要依賴的是org.apache.struts2.interceptor.FileUploadInterceptor這個(gè)攔截器

關(guān)于這個(gè)攔截器我不想做過多的研究，這里主要討論的是該攔截器里面定義的幾個(gè)關(guān)于文件上傳的重要屬性。

protected Long maximumSize;   //允許上傳單個(gè)文件的大小單位為字節(jié)

protected String allowedTypes; //允許上傳的文件類型詳見tomcat中web.xml文件

protected Set allowedTypesSet; //允許上傳的文件類型Set集合詳見tomcat中web.xml文件 allowedTypes與allowedTypesSet屬性如有多個(gè)值之間用逗號(hào)隔開 以上的屬性主要配置在struts.xml中對(duì)應(yīng)文件上傳Action的攔截器中

示列：

<!-- 文件上傳Action -->          <action name="Upload" class="UploadAction">              <result name="success">success.jsp</result>              <result name="input">upload.jsp</result>              <interceptor-ref name="fileUpload"> //設(shè)置允許上傳單個(gè)文件的大小單位為字節(jié)                  <param name="maximumSize">102400</param> //允許上傳的文件類型詳見tomcat中web.xml文件                <param name="allowedTypesSet">application/msword</param>              </interceptor-ref>              <interceptor-ref name="defaultStack"/>          </action>

注意：要使用文件上傳功能我們必須顯實(shí)的在對(duì)應(yīng)文件上傳的Action中指定<interceptor-ref name="fileUpload">這個(gè)攔截器及在該攔截器中配置我們需要的參數(shù)，最后別忘了附加上<interceptor-ref name="defaultStack"/>這個(gè)默認(rèn)的攔截器，這樣才能真正發(fā)揮struts2的文件上傳功能。

示列代碼：

Action中的示列代碼

publicclass FileUploadAction extends ActionSupport {     private File file;     private String fileContentType;     private String fileFileName;     private String memo;     @Override     public String execute() throws Exception {         String path=ServletActionContext.getRequest().getRealPath("/upload");         if(file==null)         {             this.addFieldError("file", "文件不能為空，請(qǐng)選擇");             returnINPUT;         }else         {             InputStream is=new FileInputStream(this.getFile());             OutputStream os=new FileOutputStream(new File(path,this.getFileFileName()));             byte[] buf=newbyte[1024];             int length=0;             while((length=is.read(buf))>0)             {                 os.write(buf, 0, length);             }             is.close();             os.close();         }         returnSUCCESS;     }     public File getFile() {         returnfile;     }     publicvoid setFile(File file) {         this.file = file;     }     public String getFileContentType() {         returnfileContentType;     }     public String getFileFileName() {         returnfileFileName;     }     public String getMemo() {         returnmemo;     }     publicvoid setFileContentType(String fileContentType) {         this.fileContentType = fileContentType;     }     publicvoid setFileFileName(String fileFileName) {         this.fileFileName = fileFileName;     }     publicvoid setMemo(String memo) {         this.memo = memo;     } }

jsp中的示列代碼

<s:form action="Upload" enctype="multipart/form-data" method="post">     <s:file name="file"></s:file>     <s:textfield name="memo"></s:textfield>     <s:submit></s:submit> </s:form>

struts.xml中的示列代碼

<action name="Upload" class="UploadAction">              <result name="success">/success.jsp</result>              <result name="input">/upload.jsp</result>              <interceptor-ref name="fileUpload">                  <param name="maximumSize">102400</param>                  <param name="allowedTypes">application/msword</param>              </interceptor-ref>              <interceptor-ref name="defaultStack"/> </action>

注意：

a)       設(shè)置文件上傳屬性在Action中對(duì)應(yīng)的類型的java.io.File;

b)       設(shè)置文件上傳表單的enctype="multipart/form-data" method="post"

private File file; private String fileContentType; private String fileFileName;

c)       紅色標(biāo)注的與文件上傳表單中文件上傳屬性的name一致

d)       藍(lán)色的為固定寫法

e)       對(duì)應(yīng)Action中攔截器的配置

<interceptor-ref name="fileUpload">

                 <param name="maximumSize">102400</param>

                 <param name="allowedTypes">application/msword</param>

</interceptor-ref>

<interceptor-ref name="defaultStack"/>

Struts2多文件上傳示例代碼：

jsp上傳頁面代碼:

<%@ page language="java" contentType="text/html; charset=gbk"     pageEncoding="gbk"%> <%@ taglib prefix="s" uri="/struts-tags"%>  <!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=gbk"> <title>Insert title here</title> </head> <script type="text/javascript">     function clickme()     {         var divs=document.getElementById('mydiv');         var br=document.createElement('br');         var input=document.createElement('input');         input.type="file";         input.name="file"         var button=document.createElement('input');         button.type="button";         button.value="remove";         divs.appendChild(br);         divs.appendChild(input);         divs.appendChild(button);         button.onclick=function()         {             divs.removeChild(br);             divs.removeChild(input);             divs.removeChild(button);         }     } </script> <body> <h1>Struts2</h1> <s:fielderror name="file"/> <s:form action="Upload" enctype="multipart/form-data" method="post">     <s:file name="file" theme="simple"></s:file>     <input type="button" value="Add More" onclick="clickme()"/>     <div id="mydiv">     </div>     <s:textfield name="memo"></s:textfield>     <s:submit></s:submit> </s:form> </body> </html>

Actio中代碼:用戶自己寫代碼來判斷文件類型及文件大小

package com.struts2.action; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.util.List; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; @SuppressWarnings("serial") public class FileUploadAction extends ActionSupport {          private List<File> file;          private List<String> fileContentType;          private List<String> fileFileName;          private String memo;          @Override          public String execute() throws Exception {                    String path=ServletActionContext.getRequest().getRealPath("/upload");                    if(file==null)                    {                             this.addFieldError("file", "文件不能為空，請(qǐng)選擇");                             return INPUT;                    }else                    {                             InputStream is = null;                             OutputStream os = null;                             File f=null;                             long fileSize=0;                             String ext="";                             for (int i = 0; i < file.size(); i++) {                                      ext=fileFileName.get(i).substring(fileFileName.get(i).lastIndexOf(".")+1);                                      f=this.getFile().get(i);                                      fileSize=f.length();                                      System.out.println("fileSize:"+fileSize);                                      System.out.println("ext:"+ext);                                      if("exe".equals(ext)||"jar".equals(ext)||"bat".equals(ext)||"msi".equals(ext))                                      {                                                this.addFieldError("file", "the file is not allowed");                                                return INPUT;                                      }                                                                           if(fileSize>102000)                                      {                                                this.addFieldError("file", "the file is too large");                                                return INPUT;                                      }                                                                           is=new FileInputStream(f);                                      os=new FileOutputStream(new File(path,this.getFileFileName().get(i)));                                      byte[] buf=new byte[1024];                                      int length=0;                                      while((length=is.read(buf))>0)                                      {                                                os.write(buf, 0, length);                                       }                             }                             is.close();                             os.close();                    }                    return SUCCESS;          }          public List<File> getFile() {                    return file;          }          public void setFile(List<File> file) {                    this.file = file;          }          public List<String> getFileContentType() {                    return fileContentType;          }          public void setFileContentType(List<String> fileContentType) {                    this.fileContentType = fileContentType;          }          public List<String> getFileFileName() {                    return fileFileName;          }          public void setFileFileName(List<String> fileFileName) {                    this.fileFileName = fileFileName;          }          public String getMemo() {                    return memo;          }          public void setMemo(String memo) {                    this.memo = memo;          } }

Struts.xml中配置代碼:

<!-- 文件上傳Action -->                <action name="Upload" class=" com.struts2.action.FileUploadAction">             <result name="success">/success.jsp</result>             <result name="input">/upload.jsp</result>             <interceptor-ref name="fileUpload">             <!--                <param name="maximumSize">102400</param>                <param name="allowedTypes">application/msword</param>              -->             </interceptor-ref>             <interceptor-ref name="defaultStack"/>            </action>