Java导出数据到txt文件

Java代码


第一种形式，是以流的开式直接response,适用于数据量不是很大的情况下。

Java代码


第二种形式，是先将要下载的文件写到后台的一个文件或者excel 中，然后再进行下载。

Java代码


第一种实现：

Java代码


package com.smartdot.pdm.business.corp.magazine.util;

import java.io.BufferedOutputStream;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.List;

import javax.servlet.ServletOutputStream;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;

import com.smartdot.pdm.business.corp.magazine.bean.MagazineBean;

public class MagazineUtils {

// 输出TXT

public static void writeToTxt(HttpServletResponse response, List list) {

response.setContentType("text/plain");// 一下两行关键的设置

response.addHeader("Content-Disposition",

"attachment;filename=期刊出版社.txt");// filename指定默认的名字

BufferedOutputStream buff = null;

StringBuffer write = new StringBuffer();

String tab = " ";

String enter = "\r\n";

MagazineBean magazine;

ServletOutputStream outSTr = null;

try {

outSTr = response.getOutputStream();// 建立

buff = new BufferedOutputStream(outSTr);

for (int i = 0; i < list.size(); i++) {

magazine = (MagazineBean) list.get(i);

write.append("期刊名称：" + tab);

write.append(delNull(magazine.getChineseName()) + enter);

write.append(enter);

}

buff.write(write.toString().getBytes("UTF-8"));

buff.flush();

buff.close();

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

buff.close();

outSTr.close();

} catch (Exception e) {

e.printStackTrace();

}

}

}

public static String delNull(Date date) {

String returnStr="";

if (date!=null) {

SimpleDateFormat sf=new SimpleDateFormat("yyyy年MM月");

returnStr=sf.format(date);

}

return returnStr;

}

public static String delNull(String str) {

String returnStr="";

if (StringUtils.isNotBlank(str)) {

returnStr=str;

}

return returnStr;

}

}

第二种实现：

Java代码


// 输出TXT

public static void writeToTxt(HttpServletRequest request, List list) {

FileOutputStream outSTr = null;

BufferedOutputStream Buff = null;

String path = request.getSession().getServletContext().getRealPath(

"upordown/down/model/magazinePub.txt");

String tab = " ";

String enter = "\r\n";

MagazineBean magazine;

StringBuffer write ;

try {

outSTr = new FileOutputStream(new File(path));

Buff = new BufferedOutputStream(outSTr);

for (int i = 0; i < list.size(); i++) {

magazine = (MagazineBean) list.get(i);

write = new StringBuffer();

write.append("期刊名称：" + tab);

write.append(delNull(magazine.getTenet()) + enter);

write.append(enter);

Buff.write(write.toString().getBytes("UTF-8"));

}

Buff.flush();

Buff.close();

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

Buff.close();

outSTr.close();

} catch (Exception e) {

e.printStackTrace();

}

}

}

下载的代码：

Java代码


//下载

public ActionForward downFile(ActionMapping mapping, ActionForm form,

HttpServletRequest request, HttpServletResponse response)

throws Exception {

String name=request.getParameter("filename");

// TODO Auto-generated method stub

try {

String path = request.getSession().getServletContext().getRealPath(

"upordown/down/model/"+name);

File file = new File(path);

String filename = file.getName();

// 取得文件的扩展名ext

String ext = filename.substring(filename.lastIndexOf(".") + 1)

.toUpperCase();

InputStream fis = new BufferedInputStream(new FileInputStream(path));

byte[] buffer = new byte[fis.available()];

fis.read(buffer);

fis.close();

response.reset();

response.addHeader("Content-Disposition", "attachment;filename="

+ new String(filename.getBytes()));

response.addHeader("Content-Length", "" + file.length()); // 设置返回的文件类型

OutputStream toClient = new BufferedOutputStream(response

.getOutputStream()); // 得到向客户端输出二进制数据的对象

// 根据扩展名声称客户端浏览器mime类型

if (ext.equals("xls"))

response.setContentType("application/msexcel");

else

response.setContentType("application/octet-stream"); // 设置返回的文件类型

toClient.write(buffer); // 输出数据

toClient.flush();

toClient.close();

} catch (IOException ex) {

ex.printStackTrace();

return mapping.findForward("error");

}

return null;

}

客户端调用

Js代码


//下载txt

function downTxt(){

window.open ('${pageContext.request.contextPath}/business/magazineAction.do?method=downFile&filename=magazinePub.txt', '文件下载', 'height=300, width=400, top='+(screen.availHeight-300)/2+', left='+(screen.availWidth-400)/2+', toolbar=no, menubar=no, scrollbars=no, resizable=no,location=no, status=no');

}

//导出txt

function exportTxt(){

var queryForm=document.queryForm;

var minRow=queryForm.minRow.value;

var maxRow=queryForm.maxRow.value;

var totalCnt="${totalCnt}";

if(StringUtils.isBlank(totalCnt)){

totalCnt=0;

}

if(Validator.Validate(2)){

minRow=parseInt(minRow);

maxRow=parseInt(maxRow);

// if(maxRow-minRow+1>1000){

// alert("每次最多可以导出1000条数据");

// return ;

// }

if(maxRow>totalCnt){

alert("结束记录数不能等大于总记录条数："+totalCnt);

return ;

}

if(maxRow<minRow){

alert("结束记录数不能小于开始记录数");

return ;

}

req.setRequestMethod("post");

var url="${pageContext.request.contextPath}/business/magazineAction.do?method=doExportTxt&orderColumn=${orderColumn}&orderType=${orderType}&queryCondition="+encodeURIComponent('${queryCondition}')+"&maxRow="+maxRow+"&minRow="+minRow+"&isDecorator=false";

req.setRequestURL(url);

req.setAsync(true);

req.setMethodOnSuccess(displayMsg);

req.setRequestHeader("Content-Type","text/html;charset=gbk");

req.send(null);

}

}