Extjs通过Apache的FileItem进行文件的上传下载

Extjs通过Apache的FileItem进行文件的上传下载

 

查看FileItem类的方法说明

一.上传

1.Extjs：

在FormPanel中要增加一个属性：[ fileUpload : true ]

var addNewsForm = new Ext.form.FormPanel({
	id:"addNewsForm",
	frame:true,
	layout:"form", 
	labelAlign:"right",
	labelWidth:"150",
	buttonAlign:"center",
	fileUpload : true,
	items:[{
		id:"id",
		name:"id",
		xtype:"textfield",
		fieldLabel:"编号",
		hidden:true,
		hideLabel:true
	},{
		id:"title",
		name:"title",
		xtype:"textfield",
		fieldLabel:"新闻标题",
		allowBlank:false,
		minLength:5,
		maxLength:50,
		width:750
	},{
		id:"tag",
		name:"tag",
		xtype:"textarea",
		fieldLabel:"新闻标签",
		allowBlank:false,
		maxLength:330,
		height:70,
		width:750
	},{
        name:"content",
        xtype:"StarHtmleditor",
        fieldLabel:"新闻内容",
        fontFamilies: ["宋体","隶书","黑体","楷体","幼圆"],
        width:750,
        height:230
    },typeRadio,statusRadio,{
		id:"ishot",
		name:"ishot",
		xtype:"checkbox",
		fieldLabel:"是否热点"
	},{
		id:"uploadNews",
		name:"uploadNews",
		xtype:"textfield",
		inputType:"file",
		fieldLabel:"上传文件",
		buttonText: ''
	}],
	buttons:[{
		text:"确定",
		handler:addNews
	},{
		text:"取消",
		handler:function(){
			history.go(-1);
		}
	}]
});

   

注意：当增加了该属性后，form表单提交到后台，textfield文本框的值用request获取将为null,所以此时我们需要用到Apache的FileItem来实现文本框的值的获取和上传文件的文件名。

 

2.获取表单提交请求的Servlet：

String title = "";
String tag = "";
String content = "";
String typeStr = "0";
String ishotStr = "0";
String statusStr = "0";
String uploadFileName = "";
Long time = System.currentTimeMillis(); 
Calendar cal=Calendar.getInstance();
int year=cal.get(Calendar.YEAR);//得到年
int month=cal.get(Calendar.MONTH)+1;//得到月
String newsFileDir = Configuration.getConfig().getString("newsFileDir");//从Resource.properties中读取配置信息
if (newsFileDir.contains("/")) {
	newsFileDir = newsFileDir.replace("/", File.separator);
}
String uploadFileDir = newsFileDir + File.separator + year + File.separator +month;
List<FileItem> fileItems = UploadFileUtil.getServletFileUpload().parseRequest(request);//解析Request请求
for (int i = 0; i < fileItems.size(); i++) {
	FileItem item =  fileItems.get(i);
	if (!item.isFormField()) {//判断是否是表单文本域——即不是上传文件域！
		uploadFileName = item.getName();
		Map<String, String> map = UploadFileUtil.uploadFile(uploadFileDir, item);
		if (map.get("msg") != null) {
			response.setContentType("text/html;charset=UTF-8");
			out=response.getWriter();
			out.print("{failure:\""+map.get("msg")+"\"}");		
			out.close();
			return;
		}
	}
	else {
		String newsStr = new String(item.getString().getBytes("ISO8859_1"), "UTF-8");//解决中文乱码
		if ("title".equals(item.getFieldName())) {
			title = newsStr;//将FileItem对象中保存的数据流内容以一个字符串返回。
		}
		else if ("tag".equals(item.getFieldName())) {
			tag = newsStr;
		}
		else if ("content".equals(item.getFieldName())) {
			content = newsStr;
		}
		else if ("type".equals(item.getFieldName())) {
			typeStr = newsStr;
		}
		else if ("status".equals(item.getFieldName())) {
			statusStr = newsStr;
		}
		else if ("ishot".equals(item.getFieldName())) {
			ishotStr = newsStr;
		}
	}
}
int type = Integer.valueOf(typeStr);
int status = Integer.valueOf(statusStr);
int ishot = 0;
if("on".equals(ishotStr)){
	ishot = 1;
}
INewsDao newsDao = new NewsDaoImpl();
News news = new News();
news.setTitle(title);
news.setTag(tag);
news.setType(type);
news.setIshot(ishot);
news.setContent(clob);
news.setStatus(status);
news.setUploadDir(uploadFileDir);
news.setUploadFile(uploadFileName);
done = newsDao.saveNews(news);
String str =null;
if(done){
	str="{success:true}";
}else{
	str="{success:false}";
}
response.setContentType("text/html;charset=UTF-8");
out=response.getWriter();
out.print(str);		
out.close();
return;

注意：

(1).需要通过 item.isFormField() 来判断是普通表单域还是上传域；

(2).一定要对获取到的数据流（即普通表单域中的内容）进行解码，否则会出现中文乱码！

 （FileItem类的getString方法用于将FileItem对象中保存的数据流内容以一个字符串返回）

   ——保存的数据流内容即普通文本域（非上传域）的内容！

 

3.上传文件工具类：

package com.datanew.czfc.util;

import java.io.File;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

/**
 * 创建人： zy
 * 创建时间： 2014年12月4日 下午2:46:38
 * 类描述：上传文件工具类
 */
public class UploadFileUtil {
	
	/**
	 * 获取ServletFileUpload
	 * @return
	 */
	public static ServletFileUpload getServletFileUpload(){
		FileItemFactory  factory = new DiskFileItemFactory();
		ServletFileUpload upload = new ServletFileUpload(factory);
		upload.setHeaderEncoding("UTF-8");
		return upload;
	}
	
	
	/**
	 * 上传文件
	 * @param fileDir
	 * @param fileItem
	 * @return
	 */
	public static Map<String, String> uploadFile(String fileDir,FileItem fileItem) {
		String fileName = null;
		long maxSize = 5*1024*1024;
		Map<String, String> map = new HashMap<String, String>();
		try {
			//1.判断目录是否存在，不存在则创建目录
			String[] paths;
			if (fileDir.contains("/")) {
				paths = fileDir.split("/");
			}
			else {
				paths = fileDir.split("\\\\");//注意：此处“\\”是错误的，必须要“\\\\”才能分割字符串
			}
			String dir = paths[0];
			for (int i = 1; i < paths.length; i++) {
				dir = dir + File.separator + paths[i];
				File file=new File(dir.toString());
				if (!file.exists()) {
					file.mkdir();
				}
			}
			//2.保存文件
			fileName = fileItem.getName();
			if (fileName == "" || fileName == null) {
				map.put("msg", "请先上传文件");
				return map;
			}
			long size = fileItem.getSize();
			if (size > maxSize) {
				map.put("msg", "您上传的文件过大，请重新上传");
				return map;
			}
			//fileName = System.currentTimeMillis() + fileName.substring(fileName.lastIndexOf("."));
			map.put("fileName", fileName);
			fileItem.write(new File(fileDir + File.separator +fileName));
		} catch (FileUploadException e) {
			e.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		}
		return map;
	}
}

注意：

1.要对ServletFileUpload进行编码的设置；

2.采用fileItem.write的方式进行文件的写操作，即上传文件到指定的目录；

 

二.下载：

通过新闻标题查询实体类，在通过获取的实体类中的文件路径进行文件的下载

else if ("getFile".equals(action)) {
	String title = new String(request.getParameter("title").getBytes("ISO8859_1"), "UTF-8");
	INewsDao newsDao = new NewsDaoImpl();
	String filePath  = newsDao.getFile(title);
	String str =null;
	try {
		File file = new File(filePath);
		response.setContentType("text/plain");
		//response.setHeader("Location",fileName);
		response.setHeader("Content-Disposition", "attachment;filename=" + new String(file.getName().getBytes("GBK"), "iso-8859-1"));
		OutputStream os = response.getOutputStream();
		InputStream inputStream = new FileInputStream(file);
		byte[] buffer = new byte[1024];
		int i = -1;
		while ((i = inputStream.read(buffer)) != -1) {
			os.write(buffer, 0, i);
		}
		os.flush();
		os.close();
	} catch (FileNotFoundException e) {
		System.out.println("文件未找到");
	}
	return;
}

注意：

1.要对request获取的中文进行编码；

2.要对response的ContentType和Header进行设置；

 

 

实例图示：

 

实例中解析Request获得的FileItem数据：

[
  name=null,
  StoreLocation=C: \Users\ADMINI~1\AppData\Local\Temp\upload__42856ff_14a38191494__8000_00000000.tmp,
  size=0bytes,
  isFormField=true,
  FieldName=id,
  name=null,
  StoreLocation=C: \Users\ADMINI~1\AppData\Local\Temp\upload__42856ff_14a38191494__8000_00000001.tmp,
  size=24bytes,
  isFormField=true,
  FieldName=title,
  name=null,
  StoreLocation=C: \Users\ADMINI~1\AppData\Local\Temp\upload__42856ff_14a38191494__8000_00000002.tmp,
  size=18bytes,
  isFormField=true,
  FieldName=tag,
  name=null,
  StoreLocation=C: \Users\ADMINI~1\AppData\Local\Temp\upload__42856ff_14a38191494__8000_00000003.tmp,
  size=36bytes,
  isFormField=true,
  FieldName=content,
  name=null,
  StoreLocation=C: \Users\ADMINI~1\AppData\Local\Temp\upload__42856ff_14a38191494__8000_00000004.tmp,
  size=1bytes,
  isFormField=true,
  FieldName=type,
  name=null,
  StoreLocation=C: \Users\ADMINI~1\AppData\Local\Temp\upload__42856ff_14a38191494__8000_00000005.tmp,
  size=1bytes,
  isFormField=true,
  FieldName=status,
  name=null,
  StoreLocation=C: \Users\ADMINI~1\AppData\Local\Temp\upload__42856ff_14a38191494__8000_00000006.tmp,
  size=2bytes,
  isFormField=true,
  FieldName=ishot,
  name=test.txt,
  StoreLocation=C: \Users\ADMINI~1\AppData\Local\Temp\upload__42856ff_14a38191494__8000_00000007.tmp,
  size=418bytes,
  isFormField=false,
  FieldName=uploadNews,
  name=null,
]

数据分析：

1.蓝框的是普通表单域的内容

2.红框的是上传域的内容

3.FieldName是表单中的某个item项的name