Application of JDBC

Last Update:2017-04-05 Source: Internet

Author: User

Tags getmessage stmt

Developer on Alibaba Coud: Build your first app with APIs, SDKs, and tutorials on the Alibaba Cloud. Read more ＞

Code snippet under 003.jsp

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

<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+ "/";
%>

<! 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>

<%
Out.println ("<table width= ' border= ' 1 ' >");
Out.println ("<tr>");
Out.println ("<th scope= ' col ' > Study No. </th>");
Out.println ("<th scope= ' col ' > class </th>");
Out.println ("</tr>");
String sql= "SELECT * from Information";
ResultSet rs = myjdbc01.doselect (SQL);
while (Rs.next ()) {
Out.println ("<tr>");
Out.println ("<td>");
Out.println (rs.getstring (1));
Out.println ("</td>");
Out.println ("<td>");
Out.println (rs.getstring (2));
Out.println ("</td>");
Out.println ("</tr>");
}
Out.println ("</table>");
%>

</body>

Code under the Dbconn.java class

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;

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 Dbconn (String driver,string url,string user,string password) {

try {
Driver= "Com.mysql.jdbc.Driver";
Url= "Jdbc:mysql://localhost:3306/school";
User= "Root";
Password= "711109";
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 void DoDelete (String sql) {
try {
stmt = (preparedstatement) conn.preparestatement (SQL);
int i = stmt.executeupdate (sql);
} catch (SQLException SQLException) {
System.err.println ("Db.executedelete:" + sqlexception.getmessage ());
}
}

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

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= ' Lin '");
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) {
TODO auto-generated Catch block
E.printstacktrace ();
}

Rs.close ();
Db.close ();
}
}

Application of JDBC

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

Get Started for Free

Sales Support

1 on 1 presale consultation

Chat Contact Sales
After-Sales Support

24/7 Technical Support 6 Free Tickets per Quarter Faster Response

Open a Ticket
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.

Learn More