CopyCode The Code is 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
* @ Author codingmouse
* 2009.2.20
*/
Public final class dbmanager {
/**
* Database connection object
*/
Private connection dbconnection = NULL;
/**
* DATABASE Command Execution object
*/
Private preparedstatement prestatement = NULL;
/**
* Result set object
*/
Private resultset rsset = NULL;
/**
* Database driver version
*/
Private Static string driverversion = NULL;
/**
* Database Server login username and password string constant (default value: Both
Is 'sa ')
*/
Private Static string databaseuser = "sa ";
Private Static string databasepassword = "sa ";
/**
* Database-driven complete class name String constant
*/
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 constant
*/
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
/**
* Defines the static instance variables of the class (applies to applications in the single-instance [component] mode)
*/
Private Static dbmanager connectionmanager = NULL;
/**
* Default structure of privatization (applies to applications in the single-instance [component] mode to prevent direct classes
Use the New Keyword for instantiation)
*/
Private dbmanager (){
Super ();
}
/**
* Methods for obtaining database connection management instances (single-instance [component] Mode Applications)
* @ Param version: Database driver version. Value: (version =
2000 | version = 2005 | version = ODBC)
* @ Param User: username used to log on to the Database Server
* @ Param password: Database Server logon Password
* @ Return database connection management object
* @ 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 driver version number
Incorrect. The value can only be "2000/2005/ODBC "! ");
}
// Save the database driver version
Driverversion = version;
If (user = NULL | user. Equals ("")){
Throw new exception ("Database Server login
The user name cannot be blank! ");
}
// Save the username and password for logging on to the Database Server
Databaseuser = user;
Databasepassword = password;
// The application Singleton [Parts] mode ensures that the class has only one instance
If (connectionmanager = NULL ){
Connectionmanager = new dbmanager ();
}
// Return the instance of the class.
Return connectionmanager;
}
/**
* Methods for obtaining database connections
* @ Return database connection object
*/
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 driver class: "+ ex. getmessage ());
// Output exception stack information on the console
// Ex. printstacktrace ();
} Catch (exception ex ){
System. Err. println ("An error occurred while obtaining the database connection.
Error: "+ ex. getmessage ());
// Output exception stack information on the console
// Ex. printstacktrace ();
}
// Return the database connection object
Return this. dbconnection;
}
/**
* Method for obtaining the database command execution object
* @ Param SQL the SQL command to be executed to assemble the statement string
* @ Return DATABASE Command Execution object
*/
Private preparedstatement getpreparedstatement
(String SQL ){
Try {
// Create a database based on the obtained database connection object
Command Execution object
This. prestatement = getconnection
(). Preparestatement (SQL );
} Catch (exception ex ){
System. Err. println ("Get DATABASE Command Execution
Row object error: "+ ex. getmessage ());
// Output exception stack information on the console
// Ex. printstacktrace ();
}
// Return the database command execution object
Return this. prestatement;
}
/**
* Execute the update Statement (insert | update | delete)
* @ Param SQL the SQL command to be executed to assemble the statement string
* @ Return: Number of affected rows
*/
Public int executeupdate (string SQL ){
Try {
// Empty the original content of the result set object
This. rsset = NULL;
// Execute the statement and return the number of affected rows
Return this. getpreparedstatement
(Sqlcmd.exe cuteupdate ();
} Catch (sqlexception e ){
System. Err. println ("data update error:" +
E. getmessage ());
Return 0;
} Finally {
// Closes database connection resources
Closedbresource ();
}
}
/**
* Execute the query statement (select)
* @ Param SQL the SQL command to be executed to assemble the statement string
* @ 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 an SQL statement to obtain the result set
This. rsset =
This.getpreparedstatement(sqlcmd.exe cutequery ();
} Catch (sqlexception e ){
System. Err. println ("Data Query error:" +
E. getmessage ());
}
// Return result set object
Return this. rsset;
}
/**
* Obtain the number of records in the returned result set after the specified SQL statement is executed.
* @ Param SQL the SQL command to be executed to assemble the statement string
* @ Return the number of records obtained from the query results
*/
Public int getresultsetcount (string SQL ){
// Save the counter variable for the number of records returned after the specified SQL statement is executed
Int COUNT = 0;
Try {
// Empty the original content of the result set object
This. rsset = NULL;
// Execute an SQL statement to obtain the result set
This. rsset = This. getpreparedstatement
(Sqlcmd.exe cutequery ();
// Traverse the result set and accumulate the counter
While (this. rsset. Next ()){
Count ++;
}
} Catch (sqlexception e ){
E. printstacktrace ();
}
Return count;
}
/**
* Shut down database connection resources (including result set objects, command execution objects, and connections)
Object)
*/
Public void closedbresource (){
Try {
Closeresultset ();
Closepreparedstatement ();
Closeconnection ();
} Catch (sqlexception sqlex ){
System. Err. println (sqlex. getmessage
());
// Output exception stack information on the console
// Sqlex. printstacktrace ();
}
}
/**
* Method for disabling a result set object
* @ Throws sqlexception
*/
Private void closeresultset () throws sqlexception {
Try {
If (this. rsset! = NULL ){
This. rsset. Close ();
This. rsset = NULL;
}
} Catch (sqlexception sqlex ){
Throw new sqlexception ("Disable result set pair
Error: "+ sqlex. getmessage ());
// Output exception stack information on the console
// Sqlex. printstacktrace ();
}
}
/**
* Method for disabling 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 ("Shut down database life
The execution object is incorrect: "+ sqlex. getmessage ());
// Output exception stack information on the console
// Sqlex. printstacktrace ();
}
}
/**
* Method for disabling 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 ("Disable database connection
Error: "+ sqlex. getmessage ());
// Output exception stack information on the console
// Sqlex. printstacktrace ();
}
}
}
