Some open source organizations provide a standalone implementation of the data source:
DBCP database Connection pool
C3P0 database Connection pool
Apache Tomcat built-in connection pool
DBCP Connection Pool
Apache provides a connection pool implementation that needs to be imported Common-dbcp.jar Commons-pool.jar
ImportJava.io.FileReader;Importjava.sql.Connection;ImportJava.sql.ResultSet;Importjava.sql.Statement;Importjava.util.Properties;ImportJavax.sql.DataSource;Importorg.apache.commons.dbcp.BasicDataSourceFactory; Public classDbcptest { Public Static voidMain (string[] args)throwsException {//Import configuration fileProperties prop=NewProperties (); Prop.load (NewFileReader ("Dbcp.properties")); //Get Data sourceBasicdatasourcefactory factory=Newbasicdatasourcefactory (); DataSource Pool=Factory.createdatasource (prop); Connection Conn=pool.getconnection (); //get The transmitter objectStatement statement=conn.createstatement (); //get result Set objectResultSet resultset=statement.executequery ("SELECT * from User"); //Traverse while(Resultset.next ()) {String username=resultset.getstring ("username"); SYSTEM.OUT.PRINTLN (username); } //Close ResourceResultset.close (); Statement.close (); Conn.close (); }}
Create a new dacp.properties under the project directory
Driverclassname=com.mysql.jdbc.driverurl=jdbc:mysql:///javausername=rootpassword=root
C3P0 Connection Pool
Importjava.sql.Connection;ImportJava.sql.ResultSet;Importjava.sql.Statement;ImportCom.mchange.v2.c3p0.ComboPooledDataSource; Public classDbcptest { Public Static voidMain (string[] args)throwsException {//using C3P0Combopooleddatasource pool=NewCombopooleddatasource (); Connection Conn=pool.getconnection (); //get The transmitter objectStatement statement=conn.createstatement (); //get result Set objectResultSet resultset=statement.executequery ("SELECT * from User"); //Traverse while(Resultset.next ()) {String username=resultset.getstring ("username"); SYSTEM.OUT.PRINTLN (username); } //Close ResourceResultset.close (); Statement.close (); Conn.close (); }}
C3P0 need to create a new c3p0-config.xml in the class loading directory
<?XML version= "1.0" encoding= "Utf-8"?><C3p0-config> <Default-config> < Propertyname= "Driverclass">Com.mysql.jdbc.Driver</ Property> < Propertyname= "Jdbcurl">Jdbc:mysql:///java</ Property> < Propertyname= "User">Root</ Property> < Propertyname= "Password">Root</ Property> </Default-config></C3p0-config>
[Java EE] Open source database connection pool