Copy Code code as follows:
Package com.groundhog.codingmouse;
Import java.sql.Connection;
Import Java.sql.DriverManager;
Import java.sql.PreparedStatement;
Import Java.sql.ResultSet;
Import java.sql.SQLException;
/**
* Database Management class
* @author Codingmouse
* 2009.2.20
*/
Public final class Dbmanager {
/**
* Database Connection objects
*/
Private Connection dbconnection = null;
/**
* Database Command Execution Object
*/
Private PreparedStatement prestatement = null;
/**
* Result Set Object
*/
Private ResultSet rsset = null;
/**
* Database-driven version number
*/
private static String driverversion = null;
/**
* Database server login username and password string constants (default values are
To ' sa ')
*/
private static String Databaseuser = "sa";
private static String DatabasePassWord = "sa";
/**
* Database-Driven full class name string constants
*/
private static Final String
driver_class_sqlserver2000 =
"Com.microsoft.jdbc.sqlserver.SQLServerDriver"; Sql
Server 2000 Direct Connection
private static Final String
driver_class_sqlserver2005 =
"Com.microsoft.sqlserver.jdbc.SQLServerDriver"; Sql
Server 2005 Direct Connection
private static Final String
Driver_class_bridgeconnect = "Sun.jdbc.odbc.JdbcOdbcDriver";
ODBC Bridge Connection
/**
* Database connection string Constants
*/
private static Final String
database_url_sqlserver2000 =
"Jdbc:microsoft:sqlserver://127.0.0.1:1433;databasename=stud
B "; SQL Server 2000 Direct connection
private static Final String
database_url_sqlserver2005 =
"Jdbc:sqlserver://127.0.0.1:1433;databasename=studb";
SQL Server 2005 Direct connection
private static Final String
Database_url_bridgeconnect = "Jdbc:odbc:stuDBSource";
ODBC Bridge Connection
/**
* Define the instance static variables of the class itself (for use in the case of a singleton [piece] pattern)
*/
private static Dbmanager ConnectionManager = null;
/**
* Privatization default construction (for use in single case [piece] mode application, prevent class being straight
Then instantiated with the New keyword)
*/
Private Dbmanager () {
Super ();
}
/**
* Methods for obtaining database connection management class instances (application of single case [piece] mode)
* @param version Database driver number, value: (Version =
2000 | Version = 2005 | Version = ODBC)
* @param user Database server logon username
* @param password Database server login password
* @return Database Connection Management Objects
* @throws Exception Parameter Error exception
*/
public static Dbmanager getinstance (
String version,
String User,
String password)
Throws Exception {
if (!) ( Version = = "2000" | | Version = = "2005"
|| Version = = "ODBC")) {
throw new Exception ("database-driven version number
Incorrect, the value can only be "2000/2005/ODBC"! ");
}
Save Database driver version number
DriverVersion = version;
if (user = null | | user.equals ("")) {
throw new Exception ("Database server login
User name cannot be empty! ");
}
Save Database Server login username and password
Databaseuser = user;
DatabasePassWord = password;
Apply a singleton [piece] pattern to ensure that the class itself has only one instance
if (ConnectionManager = = null) {
ConnectionManager = new Dbmanager ();
}
Returns an instance of the class itself
return ConnectionManager;
}
/**
* Ways to get a database connection
* @return Database Connection objects
*/
Private Connection getconnection () {
try {
Class.forName (
DriverVersion = =
"2000"
?
driver_class_sqlserver2000
: (DriverVersion = =
"2005"
?
driver_class_sqlserver2005
:
Driver_class_bridgeconnect));
This.dbconnection =
Drivermanager.getconnection (
DriverVersion = =
"2000"
?
database_url_sqlserver2000
: (DriverVersion = =
"2005"
?
database_url_sqlserver2005
:
Database_url_bridgeconnect),
Databaseuser,
DatabasePassWord);
catch (ClassNotFoundException ex) {
SYSTEM.ERR.PRINTLN ("SQL Server not Found"
"+ driverversion +" database-driven class: "+ Ex.getmessage ());
Output exception stack information on console
Ex.printstacktrace ();
catch (Exception ex) {
SYSTEM.ERR.PRINTLN ("Get Database connection Error")
Error: "+ ex.getmessage ());
Output exception stack information on console
Ex.printstacktrace ();
}
Return database Connection objects
return this.dbconnection;
}
/**
* Methods to get database command execution objects
* @param SQL command assembly statement string to execute
* @return Database Command execution object
*/
Private PreparedStatement Getpreparedstatement
(String SQL) {
try {
To create a database from a obtained database connection object
Command execution Object
This.prestatement = getconnection
(). preparestatement (SQL);
catch (Exception ex) {
SYSTEM.ERR.PRINTLN ("Get Database command
Row Object Error: "+ ex.getmessage ());
Output exception stack information on console
Ex.printstacktrace ();
}
Returns the database command execution object
return this.prestatement;
}
/**
* Execute UPDATE statement (insert| update| Delete)
* @param SQL command assembly statement string to execute
* @return The number of rows affected
*/
public int executeupdate (String sql) {
try {
Empty the original content of the result set object
This.rsset = null;
Executes the statement and returns the number of affected rows
Return this.getpreparedstatement
(SQL). Executeupdate ();
catch (SQLException e) {
SYSTEM.ERR.PRINTLN ("Update data error:" +
E.getmessage ());
return 0;
}finally{
To close a database connection resource
Closedbresource ();
}
}
/**
* Execute Query Statement (Select)
* @param SQL command assembly statement string to execute
* @return The result set object after the query
*/
Public ResultSet executequery (String sql) {
try {
Empty the original content of the result set object
This.rsset = null;
Execute the SQL statement to get the result set
This.rsset =
This.getpreparedstatement (SQL). ExecuteQuery ();
catch (SQLException e) {
SYSTEM.ERR.PRINTLN ("Query data error:" +
E.getmessage ());
}
Return result Set Object
return this.rsset;
}
/**
* Gets the number of record bars that return the result set after executing the specified SQL statement
* @param SQL command assembly statement string to execute
* @return The number of records obtained from the query results
*/
public int getresultsetcount (String sql) {
To save a counter variable that returns the number of rows after a specified SQL statement has been executed
int count = 0;
try {
Empty the original content of the result set object
This.rsset = null;
Execute the SQL statement to get the result set
This.rsset = This.getpreparedstatement
(SQL). ExecuteQuery ();
Iterate through the result set and accumulate the counter
while (This.rsSet.next ()) {
count++;
}
catch (SQLException e) {
E.printstacktrace ();
}
return count;
}
/**
* Close database connection resources (including result set objects, command execution objects, even
Access Object)
*/
public void Closedbresource () {
try {
Closeresultset ();
Closepreparedstatement ();
CloseConnection ();
catch (SQLException Sqlex) {
System.err.println (sqlex.getmessage
());
Output exception stack information on console
Sqlex.printstacktrace ();
}
}
/**
* methods to close result set objects
* @throws SQLException
*/
private void Closeresultset () throws SQLException {
try {
if (This.rsset!= null) {
This.rsSet.close ();
This.rsset = null;
}
catch (SQLException Sqlex) {
throw new SQLException ("Close result set pair
Like error: "+ sqlex.getmessage ());
Output exception stack information on console
Sqlex.printstacktrace ();
}
}
/**
* Methods to close database command execution objects
* @throws SQLException
*/
private void Closepreparedstatement () throws
SQLException {
try {
if (this.prestatement!= null) {
This.preStatement.close ();
This.prestatement = null;
}
catch (SQLException Sqlex) {
throw new SQLException ("Shutdown Database Life
Make the Execution object error: "+ sqlex.getmessage ());
Output exception stack information on console
Sqlex.printstacktrace ();
}
}
/**
* Methods to close the database connection
* @throws SQLException
*/
private void CloseConnection () throws SQLException {
try {
if (this.dbconnection!= null && (!)
This.dbConnection.isClosed ()) {
This.dbConnection.close ();
}
catch (SQLException Sqlex) {
throw new SQLException ("Close the database company
Connect error: "+ sqlex.getmessage ());
Output exception stack information on console
Sqlex.printstacktrace ();
}
}
}
