JDBC Operation experiment under WEB (JSP)

Last Update:2017-03-30 Source: Internet

Author: User

Tags getmessage stmt

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The code under 001.JSP

<%@ page language= "java" import= "java.util.*" pageencoding= "Utf-8"%>

<%
String path = Request.getcontextpath ();
String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";
%>

<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en"
<base href= " <%=basePath%>

<title>my JSP ' 001.jsp ' starting page</title>

<meta http-equiv= "Pragma" content= "No-cache",
<meta http-equiv= "Cache-control" content= "No-cache";
< Meta http-equiv= "expires" content= "0" >
<meta http-equiv= "keywords" content= "keyword1,keyword2,keyword3"
<meta http-equiv= "description" content= "This is my page";

<body>
<form name= "Form1" method= "Post" action= "002.jsp" >
<p>name=
<label for= "TextField" ></label>
<input type= "text" name= "myname" id= "TextField" >
</p>
<p>class=
<label for= "Textfield2" ></label>
<input type= "text" Name= "MyClass" id= "Textfield2" >
</p>
<p>
<input type= "Submit" name= "button" id= "button" value= "Submit" >
</p>
</form>
</body>

The code under 002.JSP

<%@ page language= "java" import= "java.util.*" pageencoding= "Utf-8"%>
<jsp:usebean id= "MYJDBC01" scope = "page" class= "Com.zss.www.DBConn"/>
<%
request.setcharacterencoding ("Utf-8");
String path = Request.getcontextpath ();
String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";
String myname=request.getparameter ("myname");
String myclass=request.getparameter ("MyClass");
%>

<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >
<base href= "<%=basePath%>" >

<title>my JSP ' 002.jsp ' starting page</title>

<meta http-equiv= "Pragma" content= "No-cache" >
<meta http-equiv= "Cache-control" content= "No-cache" >
<meta http-equiv= "Expires" content= "0" >
<meta http-equiv= "keywords" content= "keyword1,keyword2,keyword3" >
<meta http-equiv= "description" content= "This is my page" >
<!--
<link rel= "stylesheet" type= "Text/css" href= "Styles.css" >
-

Dbconn's JavaBean code

Package com.zss.www;

Import Java.sql.DriverManager;
Import Java.sql.ResultSet;
Import java.sql.SQLException;

Import com.mysql.jdbc.Connection;
Import com.mysql.jdbc.PreparedStatement;
Import com.mysql.jdbc.Connection;

public class Dbconn {

Private Connection Conn=null;
Private PreparedStatement Stmt=null;
Private ResultSet Rs=null;

Public Dbconn () {

try {
String driver= "Com.mysql.jdbc.Driver";
String url= "Jdbc:mysql://localhost:3306/school";
String user= "root";
String password= "lbx110";
Class.forName (driver);
conn = (Connection) drivermanager.getconnection (Url,user,password);
SYSTEM.OUT.PRINTLN ("------connection successfully----");
}catch (ClassNotFoundException classnotfoundexception) {
Classnotfoundexception.printstacktrace ();
System.err.println ("DB:" +classnotfoundexception.getmessage ());
} catch (SQLException SQLException) {
System.err.println ("Db.getconn:" +sqlexception.getmessage ());
}
}

public void Doinsert (String sql) {
try {
stmt = (preparedstatement) conn.preparestatement (SQL);
int i = stmt.executeupdate (sql);
} catch (SQLException SQLException) {
System.err.println ("Db.executeinsert:" +sqlexception.getmessage ());
}finally{

}
}

Public ResultSet doselect (String sql) {
try {
stmt = (preparedstatement) conn.preparestatement (SQL);
rs = stmt.executequery (SQL);
SYSTEM.OUT.PRINTLN ("Get result set");
} catch (SQLException SQLException) {
System.err.println ("Db.executequery:" +sqlexception.getmessage ());
}
Return RS;
}

public void Close (ResultSet rs) throws sqlexception,exception{

if (rs!=null) {
Rs.close ();
rs = null;
}

if (stmt!=null) {
Stmt.close ();
Stmt=null;
}

if (conn!=null) {
Conn.close ();
Conn=null;
}
}

public void Close () throws sqlexception,exception{

if (stmt!=null) {
Stmt.close ();
Stmt=null;
}

if (conn!=null) {
Conn.close ();
Conn=null;
}
}

public static void Main (String []args) throws exception{
Dbconn db=new dbconn ();
ResultSet rs=db.doselect ("select * from Dbuser where username= ' LBX '");
try{
while (Rs.next ()) {
System.out.println (rs.getstring (1));
System.out.println (rs.getstring (2));
System.out.println (Rs.getstring (3));
}
}catch (SQLException e) {
E.printstacktrace ();
}
Rs.close ();
Db.close ();
}

}

JDBC Operation experiment under WEB (JSP)

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