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.
packagedatatest; importjava.io.BufferedOutputStream; importjava.io.IOException; importjava.io.UnsupportedEncodingException; importjava.net.URLEncoder; importjava.sql.ResultSet; importjava.sql.SQLException; importjavax.servlet.ServletException; importjavax.servlet.ServletOutputStream; importjavax.servlet.http.HttpServlet; importjavax.servlet.http.HttpServletRequest; importjavax.servlet.http.HttpServletResponse; importbean.ConnDB; publicclassexportextendsHttpServlet{ publicvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse) throwsServletException,IOException{ //设置编码 response.setCharacterEncoding("UTF-8"); //连接数据库 ConnDBconn=newConnDB(); ServletOutputStreamoutputstream=null; BufferedOutputStreambuffoutputstream=null; Stringtxt_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")); StringBufferwrite=newStringBuffer(); outputstream=response.getOutputStream(); buffoutputstream=newBufferedOutputStream(outputstream); //根据id查询数据库 intid=Integer.parseInt(request.getParameter("id")); Stringsql="selecta.id,name,account,password"; sql+="fromtest_ranka"; sql+="leftjointest_joinbonb.id=a.idwherea.id="+id; ResultSetrs=conn.doQuery(sql); Stringcontent=""; 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(SQLExceptione){ //TODOAuto-generatedcatchblock e.printStackTrace(); } //write.append(content); //设置编码防止中文乱码 Stringstr=newString(write.toString().getBytes(),"gbk"); buffoutputstream.write(str.toString().getBytes("gbk")); buffoutputstream.flush(); }catch(IOExceptione){ //TODOAuto-generatedcatchblock e.printStackTrace(); } finally{ if(outputstream!=null) try{ outputstream.close(); }catch(IOExceptione){ //TODOAuto-generatedcatchblock e.printStackTrace(); } if(buffoutputstream!=null) try{ buffoutputstream.close(); }catch(IOExceptione){ //TODOAuto-generatedcatchblock e.printStackTrace(); } } } publicvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse) throwsServletException,IOException{ this.doGet(request,response); } }
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