The count of simple statistics

Abstract: simple count of Statistics

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JSP recent study. Read a book, read others in the online writing some simple counter, his hands began to write one, and now share. Feeling can be for beginners, it should be learning is a good example, designed to JAVABEAN, SESSION connecting to the database and some simple question, but for beginners, it can deepen the understanding of these concepts.
I do simple statistics, the main anti-updated record of visiting IP, IP number of these simple statistical functions first to design databases. I have a simple ACCESS (mainly the easy-to-use), the first two in the ACCESS in the design table: 1, counter table (including 2: Number, counter) - This table is used to record the number of visits.
2, iptables table (including 2: Number, IP) - This table is used to record the IP address of visitors. Well, good database design, as long as the following on your machine can be registered under the ODBC Rafah, I registered here ODBC data source is counter
Well, I am now the procedure code stickers out:
/ / CounterBean.java
Package yg;
Import java.io. *;
Import java.sql .*;

Public class CounterBean extends Object (
String sDBDriver = "sun.jdbc.odbc.JdbcOdbcDriver";
String sConnStr = "jdbc: odbc: count";
Private Connection conn = null;
Private Statement stmt = null;
ResultSet rs = null;
/ / Registration database-driven procedures
Public CounterBean () (
Try (
Class.forName (sDBDriver);
)
Catch (java.lang.ClassNotFoundException e) (
System.err.println ( "CounterBean ():" + e.getMessage ());
)
)

/ / Definition of the establishment of a database connectivity and data query
Public ResultSet executeQuery (String sql) (
Rs = null;
Try (
Conn = DriverManager.getConnection (sConnStr);
Stmt = conn.createStatement ();
Rs = stmt.executeQuery (sql);
)
Catch (SQLException e) (
System.err.println ( "executeQuery:" + e.getMessage ());
)
Return rs;
)

/ / Definition of data manipulation
Public void executeUpdate (String sql) (
Stmt = null;
Rs = null;
Try (
Conn = DriverManager.getConnection (sConnStr);
Stmt = conn.createStatement ();
Stmt.executeUpdate (sql);
Stmt.close ();
Conn.close ();
)
Catch (SQLException ex) (
System.err.println ( "executeUpdate:" + ex.getMessage ());
)
)

/ / Database closed
Public void closeStmt () (
Try (
Stmt.close ();
)
Catch (SQLException e) (
E.printStackTrace ();
)
)

Public void closeConn () (
Try (
Conn.close ();
)
Catch (SQLException e) (
E.printStackTrace ();
)
)
/ / Synchronous updated counter
Public synchronized int getcount () (
Int count = 0;
Rs = null;
Try (
ExecuteUpdate ( "update counter set counter = counter +1");
Rs = executeQuery ( "select counter from counter");
Rs.next ();
Count = rs.getInt (the "counter");
Stmt.close ();
Conn.close ();
) Catch (SQLException e) ()
Return count;
)
)

/ / Counter.jsp
<% @ Page contentType = "text / html; gb2312 charset ="%>
<% @ Page import = "yg.CounterBean"%>
<% @ Page import = "java.io. *"%>
<% @ Page import = "java.sql .*"%>

<head>

</ Head>
<body>

<%
String cont = new String ();
String ips = new String ();
Int ipnum = 0;
ResultSet rs;
Rs = null;
If (session.isNew ()) (
Cont = String.valueOf (counter.getcount ());// from visits
Session.putValue ( "count", cont);
Ips = request.getRemoteAddr ();// visitor's IP
Rs = counter.executeQuery ( "select ip from iptables where ip = '" + ips +"'");
If (! Rs.next ())// If there is no record of this IP database
Counter.executeUpdate ( "insert into iptables (ip) values ( '" + ips +"')");// insert a record of IP
)
Rs = counter.executeQuery ( "select ip from iptables");
While (rs.next ()){// statistics of IP
Ipnum ipnum = +1;
)
Counter.closeStmt ();
Counter.closeConn ();
Session.putValue ( "ipnum" String.valueOf (ipnum));
%>
You are the <% = session.getValue ( "count")%> visitors