Simple use of the C3P0 connection pool

First, C3P0 is a connection pooling plugin

Jar Package Required:

　　

Use manual configuration:

/*** Manual configuration using C3P0 *@throwspropertyvetoexception *@throwsSQLException*/@Test Public voidFUN1 ()throwspropertyvetoexception, sqlexception{//To create a connection pool objectCombopooleddatasource datasource=NewCombopooleddatasource (); //four-parameter configuration of the poolDatasource.setdriverclass ("Com.mysql.jdbc.Driver"); Datasource.setjdbcurl ("Jdbc:mysql://127.0.0.1:3306/demo"); Datasource.setuser ("Guodaxia"); Datasource.setpassword ("961012gz"); //Pool ConfigurationDatasource.setacquireincrement (5); Datasource.setinitialpoolsize (20); Datasource.setminpoolsize (2); Datasource.setmaxpoolsize (50); Connection Con=datasource.getconnection ();        System.out.println (con);    Con.close (); }    

C3P0 is allowed through XML configuration, similar to Hibernate.cfg.xml:

C3P0 Configuration requirements:
File name: Must be called C3p0-config.xml
File location: Must be under SRC

C3p0-config.xml:

<?XML version= "1.0" encoding= "UTF-8"?><C3p0-config>    <!--Default Connection Configuration -    <Default-config>         <!--connecting four parameter configurations -        < Propertyname= "Jdbcurl">Jdbc:mysql://127.0.0.1:3306/demo</ Property>        < Propertyname= "Driverclass">Com.mysql.jdbc.Driver</ Property>        < Propertyname= "User">Guodaxia</ Property>        < Propertyname= "Password">961012gz</ Property>        <!--Pool parameter Configuration -        < Propertyname= "Acquireincrement">3</ Property>        < Propertyname= "Initialpoolsize">10</ Property>        < Propertyname= "Minpoolsize">2</ Property>        < Propertyname= "Maxpoolsize">10</ Property>    </Default-config>        <!--specifically connected to Oracle, the analog -    <Name-configname= "Oracle-config">         <!--connecting four parameter configurations -        < Propertyname= "Jdbcurl">Jdbc:mysql://127.0.0.1:3306/demo</ Property>        < Propertyname= "Driverclass">Com.mysql.jdbc.Driver</ Property>        < Propertyname= "User">Guodaxia</ Property>        < Propertyname= "Password">961012gz</ Property>        <!--Pool parameter Configuration -        < Propertyname= "Acquireincrement">3</ Property>        < Propertyname= "Initialpoolsize">10</ Property>        < Propertyname= "Minpoolsize">2</ Property>        < Propertyname= "Maxpoolsize">10</ Property>    </Name-config></C3p0-config>

Use the default configuration in the configuration file:

 /**    @throws   SQLException  */  @Test  public  void  fun2 () throws   sqlexception{ /**   */  Combopooleddatasource dataSource  =new          Combopooleddatasource ();        Connection con  =datasource.getconnection ();        System.out.println (con);    Con.close (); }    

The configuration file can be configured with multi-song configuration information, can be manually selected:

Use the specified configuration:

/*** Use named configuration *@throwsSQLException*/@Test Public voidFUN3 ()throwssqlexception{/*** constructor Parameters specify the name of the configuration element of the E-<name-config name= "Oracle-config" >*/Combopooleddatasource DataSource=NewCombopooleddatasource ("Oracle-config"); Connection Con=datasource.getconnection ();        System.out.println (con);    Con.close (); }

JDBC Connection pool after c3p0:

 PackageCn.itcast.jdbc;Importjava.sql.Connection;Importjava.sql.SQLException;ImportJavax.sql.DataSource;ImportCom.mchange.v2.c3p0.ComboPooledDataSource; Public classJdbcutils {/** configuration file for Demon person configuration! Ask you to give c3p0-config.     xnl! */    Private StaticCombopooleddatasource datasource=NewCombopooleddatasource (); /*** Use connection pooling to return a connection object *@return     * @throwsSQLException*/     Public StaticConnection getconnection ()throwssqlexception{returndatasource.getconnection (); }        /*** Return Connection pool Object *@return     */     Public StaticDataSource Getdatasource () {returnDataSource; }}

Simple use of the C3P0 connection pool