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.
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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);
}
}
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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服务器之家。