"Use JDBC and servlet for viewing article visits"

Java code

1. Package com.lm.org;

•   

• Import java.io.ioexception;  

• Import java.io.printwriter;  

• Import java.sql.connection;  

• Import java.sql.drivermanager;  

• Import java.sql.preparedstatement;   

• Import java.sql.resultset;  

• Import java.sql.sqlexception;   

•   

• Import javax.servlet.servletcontext;  

• Import javax.servlet.servletexception;  

• Import javax.servlet.http.httpservlet;  

• Import javax.servlet.http.httpservletrequest;  

• Import javax.servlet.http.httpservletresponse;  

•   

•   

• /** 

• * Servlet Implementation Class Test

• */

• public class Test extends HttpServlet {

• Private static final long serialversionuid = 1L;

• /**

• */

• Public Test () {

• Super ();

• }

• /**

• */

• protected void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {

• This.dopost (request, response);

• }

• /**

•      */  

•     protected void DoPost (HttpServletRequest request,  

•              httpservletresponse response) throws Servletexception, IOException {  

•   & nbsp;     request.setcharacterencoding ("Utf-8");   

•          response.setcharacterencoding ("Utf-8");   

•         printwriter out = Response.getwriter ();   

•            

• HttpSession session = Request.getsession ();//Get session

• ServletContext application = Super.getservletcontext ();

• Integer accesscount = (integer) application.getattribute ("Accesscount");//Database query out

• Integer Wiewscount=null;

• Connection Connection = null;

• String sql= "SELECT * from T_news where id=1";//wiewscount

• PreparedStatement Ps=null;

• ResultSet Rs=null;

• try {

• Connection=getconnection ();

• PS = connection.preparestatement (SQL);

• rs = Ps.executequery ();

• if (Rs.next ()) {

• Wiewscount = Rs.getint ("Wiewscount");

• if (wiewscount==null) {

• Wiewscount = 1;

• }else{

• Wiewscount = Wiewscount + 1;

• Connection cn =getconnection ();

• String sql1= "Update t_news set wiewscount=" +wiewscount+ "where id=1";

• PreparedStatement preparestatement = cn.preparestatement (SQL1);

• int executeupdate = Preparestatement.executeupdate ();

• if (executeupdate>0) {

• System.out.println ("1");

• }else{

• SYSTEM.OUT.PRINTLN (2);

• }

• Cn.close ();

• Cn=null;

• Preparestatement.close ();

• Preparestatement=null;

• }

• }

• } catch (SQLException e) {

• E.printstacktrace ();

• }finally{

• try {

• Connection.close ();

• Connection=null;

• Ps.close ();

• Ps=null;

• Rs.close ();

• Rs=null;

• } catch (SQLException e) {

• E.printstacktrace ();

• }

• }

• Integer AC;

• try {

• AC = accesscount (request, response);

• OUT.PRINTLN ("Analog value =" +ac+ "\ t Database value =" +wiewscount);

• } catch (Exception e) {

• E.printstacktrace ();

• }

• Out.flush ();

• Out.close ();

• }

• public static Integer Accesscount (HttpServletRequest request,httpservletresponse response) throws exception{

• HttpServletRequest hs= (httpservletrequest) request;

• ServletContext application = Hs.getservletcontext ();

• Integer accesscount = (integer) application.getattribute ("Accesscount");//Database query out

• If=null

• if (Accesscount = = null) {

• Accesscount = 1;

• Application.setattribute ("Accesscount", Accesscount);

• } else {

• else +1 and modify the values of the database

• Accesscount = Accesscount + 1;

• Application.setattribute ("Accesscount", Accesscount);

• Update

• }

• return accesscount;

• }

• /**

• * @return

• */

• public static Connection getconnection () {

• Connection conn = null;

• try {

• Class.forName (Driver);

• conn = Drivermanager.getconnection (Url, UserName, PassWord);

• } catch (Exception e) {

• E.printstacktrace ();

• }

• Return conn;

• }

• private static String Driver = "com.mysql.jdbc.Driver";//Configutils.getproperty ("Jdbc.driver");

• private static String Url = "Jdbc:mysql://localhost:3306/test?characterencoding=utf8";//Configutils.getproperty (" Jdbc.url ");

• private static String UserName = "root";//Configutils.getproperty ("Jdbc.username");

• private static String PassWord = "root";//Configutils.getproperty ("Jdbc.password");

• }

"Use JDBC and servlet for viewing article visits"