struts2 uploadify配合使用，以及处理session丢失问题

直接上代码：

jsp页面中：

<div style="margin: 20px;">
      <span>当前最新固件 :</span><label style="margin-left: 10px; color: red;" id="currentFirmware"></label>
    </div>
    <div style="margin: 20px;">
      <p><input type="file" name="firmware" id="firmware" /></p><!-- 注意name的写法 -->
      <p style="margin: 20px 0px 0px 15px;"> <a href="#" class="easyui-linkbutton" data-options="iconCls:'icon-upload'" οnclick="doUpload();">上 传 固 件</a> (上传固件到服务器，并不更新网关)</p>
      <p style="margin: 20px 0px 0px 15px;"> <a href="#" class="easyui-linkbutton" data-options="iconCls:'icon-update'" οnclick="updateGateway();">更 新 固 件</a> (把服务器上最新的固件远程更新到网关)</p>
    </div>

js:

var path = '<%=request.getContextPath()%>';
      var sessionId = '<%=request.getSession().getId()%>';
 
 
 
 
 
$(function() {
  $('#firmware').uploadify( {
    'buttonText' : '选 择 固 件',
    'fileObjName' : 'firmware', // 需和input的name，以及struts2中的三个文件上传属性一致
    'swf' : path + '/js/uploadify/uploadify.swf',
    'uploader' : path + '/doUpload.action', // 必须全路径  uploadPorcessServlet
    'multi' : false,
    'auto' : false,
    'fileTypeDesc' : '固件',
    'fileTypeExts' : '*.bin',
    'formData' : {
      'sessionId' : sessionId
    },// sessionId用于解决session丢失的问题
    'fileSizeLimit' : '10240KB',
    'removeCompleted' : false,
    'onUploadSuccess' : function(file, data, response) {
      //alert('The file ' + file.name + ' was successfully uploaded with a response of ' + response + ':' + data);
    if (data != null && data != '' && data != 'null') {
      $.messager.alert('提示信息', data, 'info');
      return;
    } else {
      $.messager.alert('提示信息', '上传成功', 'info');
      //得到最新固件信息
      getNewest();
    }
  }
  });

  //页面初始化时得到服务器上的最新固件
  getNewest();
});

java类：

因为新的jdk已不支持通过sessionId得到session，所以要自己写个hashMap，保存session

package com.mhm.dto;

import javax.servlet.http.HttpSession;
import java.util.HashMap;

public class LedSessionContext {
  private static LedSessionContext instance;
  private HashMap<String, HttpSession> sessionMap;

  private LedSessionContext() {
    sessionMap = new HashMap<String, HttpSession>();
  }

  public static LedSessionContext getInstance() {
    if (instance == null) {
      instance = new LedSessionContext();
    }
    return instance;
  }

  public synchronized void AddSession(HttpSession session) {
    if (session != null) {
      sessionMap.put(session.getId(), session);
    }
  }

  public synchronized void DelSession(HttpSession session) {
    if (session != null) {
      sessionMap.remove(session.getId());
    }
  }

  public synchronized HttpSession getSession(String sessionId) {
    if (sessionId == null)
      return null;
    return (HttpSession) sessionMap.get(sessionId);
  }

}

监听session的创建以及销毁

package com.mhm.listener;

import java.util.HashMap;

import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

import com.mhm.dto.LedSessionContext;

public class SessionListener implements HttpSessionListener {

  public static HashMap<String, HttpSession> sessionMap = new HashMap<String, HttpSession>();  
  
  private LedSessionContext lsc = LedSessionContext.getInstance();  
  
  @Override
  public void sessionCreated(HttpSessionEvent httpSessionEvent) {
    lsc.AddSession(httpSessionEvent.getSession());  
  }

  @Override
  public void sessionDestroyed(HttpSessionEvent httpSessionEvent) {
    HttpSession session = httpSessionEvent.getSession();  
    lsc.DelSession(session);
  }
  
}

Action:

// =========== 供上传使用的字段，必须和jsp页面一致=============
  private File firmware;
  private String firmwareFileName;
  private String firmwareFileContentType;
  // =========== 供上传使用的字段=============

@Action(value = "doUpload", results = { @Result(name = Constants.SUCCESS, type = "json") })
  public String doUpload() {
    log.info("method begin: doUpload()");
    PrintWriter out = null;
    try {
      HttpServletResponse response = getResponse();
      response.setContentType("text/html;charset=UTF-8");
      out = getResponse().getWriter();
      
      
      String sessionId = (String)getRequest().getParameter("sessionId");
      HttpSession session = LedSessionContext.getInstance().getSession(sessionId);
      Userinfo user = (Userinfo)session.getAttribute(LedConstants.LOGINUSER);
      
      if (user == null) {
        rtnMsg = "用户未登录或登录已超时。上传失败";
        out.print(rtnMsg);
        out.flush();
        out.close();
      } else {
        String path = getRequest().getSession().getServletContext().getRealPath("/upload");
        System.out.println("path : " + path);
        
        // 对文件类型过滤赞不考虑
        
        if (firmware != null) {
          StringBuilder newFileName = new StringBuilder();
          int dotPos = firmwareFileName.indexOf(".");
          String fName = firmwareFileName.substring(0, dotPos);
          
          newFileName.append(fName)
          .append("-")
          .append(UUID.randomUUID())
          .append(firmwareFileName.substring(dotPos));
          
                File savefile = new File(new File(path), newFileName.toString());
                
                if (!savefile.getParentFile().exists()) {
                    savefile.getParentFile().mkdirs();
                }
                
          FileUtils.copyFile(firmware, savefile);
          
          
          // 上传信息存入数据库
          Uploadfile entity = new Uploadfile();
          entity.setFname(newFileName.toString());
          entity.setOriginalName(firmwareFileName);
          entity.setFilePath(path + "\\" + newFileName.toString());
          entity.setType(Constants.INT_VALUE1);
          entity.setFlag(Constants.INT_VALUE1);
          entity.setCreateDate(getNowTimestamp());
          entity.setCreateUser(user.getUserId());
          
          uploadFileMng.save(entity);
          out.print("");
          out.flush();
          out.close();
        }
          }
    } catch (IOException ex) {
      log.error("doUpload()", ex);
      rtnMsg = ex.getLocalizedMessage();
      out.print(rtnMsg);
      out.flush();
      out.close();
    }
    log.info("method begin: doUpload()");
    return SUCCESS;
  }