java实现数据库的数据写入到txt的方法

本文讲解如何用java实现把数据库的数据写入到txt中 并实现类似下载软件的样子在网页中弹出下载.

package datatest;

import java.io.bufferedoutputstream;
import java.io.ioexception;
import java.io.unsupportedencodingexception;
import java.net.urlencoder;
import java.sql.resultset;
import java.sql.sqlexception;

import javax.servlet.servletexception;
import javax.servlet.servletoutputstream;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;

import bean.conndb;


public class export extends httpservlet {
 public void doget(httpservletrequest request, httpservletresponse response)
   throws servletexception, ioexception {
  //设置编码
  response.setcharacterencoding("utf-8");
  //连接数据库
  conndb conn = new conndb();
  servletoutputstream outputstream = null;
  bufferedoutputstream buffoutputstream = null; 
  string txt_name = "导出的txt文件名.txt";//导出的txt文件名
  try {
   response.reset();// 清空输出流
   response.setcontenttype("text/plain;charset=utf-8");
   //设置txt文件名称编码，防止中文乱码
   response.setheader("content-disposition", "attachment; filename="+urlencoder.encode(txt_name, "utf-8"));
  stringbuffer write = new stringbuffer();
   outputstream=response.getoutputstream();
   buffoutputstream = new bufferedoutputstream(outputstream);
  //根据id查询数据库
   int id=integer.parseint(request.getparameter("id"));
   string sql = "select a.id,name,account,password ";
   sql+="from test_rank a ";
   sql+="left join test_join b on b.id=a.id where a.id="+id;
   resultset rs = conn.doquery(sql);
   string content="";
   try {
    while(rs.next())
    {
     //把数据库中读取的数据写入
     content=rs.getstring("name")+"\r\n";//在txt中换行为\t\n
     write.append(content);
     content=rs.getstring("account")+"\r\n";
     write.append(content);
     break;
    }
   } catch (sqlexception e) {
    // todo auto-generated catch block
    e.printstacktrace();
   }
   //write.append(content);
   //设置编码 防止中文乱码
   string str = new string(write.tostring().getbytes(),"gbk");
   buffoutputstream.write(str.tostring().getbytes("gbk"));
   buffoutputstream.flush();
  } catch (ioexception e) {
   // todo auto-generated catch block
   e.printstacktrace();
  }
  finally {
   if (outputstream != null)
    try {
     outputstream.close();
    } catch (ioexception e) {
     // todo auto-generated catch block
     e.printstacktrace();
    }
   if (buffoutputstream != null)
    try {
     buffoutputstream.close();
    } catch (ioexception e) {
     // todo auto-generated catch block
     e.printstacktrace();
    }
  }

 }
 public void dopost(httpservletrequest request, httpservletresponse response)
   throws servletexception, ioexception {
  this.doget(request, response);
 }

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。