Database connection pools C3P0 and DBCP

The most common open source data connection pools are c3p0, dbcp, and Proxool, with three of them:
The Hibernate Development Group recommends the use of c3p0;
Spring Development Group recommends the use of DBCP (DBCP connection pool has WebLogic connection pool the same problem, is forced to close the connection or the database restart, cannot reconnect, tell the connection is reset, this setting can be resolved);
Hibernate in action recommends using C3P0 and proxool;

DBCP Required jar:Commons-dbcp.jar, Commons-pool.jar
C3P0 Required jar:C3p0-0.9.2.1.jar mchange-commons-java-0.2.3.4.jar

Proxool no contact for the time being

C3P0 is an open source JDBC connection pool that implements the data source and Jndi bindings, and supports the standard extensions of the JDBC3 specification and JDBC2. The open source projects that currently use it are hibernate,spring and so on.
DBCP Introduction:
DBCP (database connection pool), DB connection pool. is a Java Connection pool project on Apache and a connection pool component used by Tomcat. Use of DBCP alone requires 3 packages: Common-dbcp.jar,common-pool.jar, Common-collections.jar because establishing a database connection is a very time-consuming and resource-intensive behavior, the connection pool is pre-established with the database to make some connections, put in memory, the application needs to establish a database connection directly to the connection pool to apply for a line, run out and then put back.
The difference between C3P0 and DBCP:
DBCP does not automatically recycle the idle connection function C3P0 has the automatic recycle idle connection function
The two are mainly to the data connection processing way different! The C3P0 provides maximum idle time and DBCP provides the maximum number of connections.
The former connection is broken when the connection exceeds the maximum idle connection time. DBCP all connections will be disconnected when the number of connections exceeds the maximum number of connections.

How to configure:

  <!--Configuring DBCP Data Sources -      <BeanID= "DataSource2"Destroy-method= "Close"class= "Org.apache.commons.dbcp.BasicDataSource">        < Propertyname= "Driverclassname"value= "${jdbc.driverclassname}"/>        < Propertyname= "url"value= "${jdbc.url}"/>        < Propertyname= "username"value= "${jdbc.username}"/>        < Propertyname= "Password"value= "${jdbc.password}"/>        <!--number of connections created at pool startup -        < Propertyname= "InitialSize"value= "5"/>        <!--the maximum number of connections that can be allocated from the pool at the same time. When set to 0, it means no limit.  -        < Propertyname= "Maxactive"value= "+"/>        <!--the maximum number of idle connections that will not be released in the pool. When set to 0, it means no limit.  -        < Propertyname= "Maxidle"value= " the"/>        <!--The minimum number of connections that remain idle in the pool without creating a new connection.  -        < Propertyname= "Minidle"value= "3"/>        <!--set the auto-recycle timeout connection -          < Propertyname= "removeabandoned"value= "true" />        <!--Auto-Reclaim time-out (in seconds) -          < Propertyname= "Removeabandonedtimeout"value= "$"/>        <!--set the time-out error for printing a connection when the auto-recycle time-out connection -         < Propertyname= "logabandoned"value= "true"/>        <!--The wait time-out in milliseconds, before the exception is thrown, the maximum time the pool waits for the connection to be reclaimed (when no connection is available).  Set to 1 to indicate an infinite wait.  -          < Propertyname= "Maxwait"value= "+"/>        </Bean>          <!--configuring C3P0 Data Sources -    <BeanID= "DataSource"class= "Com.mchange.v2.c3p0.ComboPooledDataSource"Destroy-method= "Close">        < Propertyname= "Jdbcurl"value= "${jdbc.url}" />        < Propertyname= "Driverclass"value= "${jdbc.driverclassname}" />        < Propertyname= "User"value= "${jdbc.username}" />        < Propertyname= "Password"value= "${jdbc.password}" />        <!--the maximum number of connections that are kept in the connection pool. Default:15 -        < Propertyname= "Maxpoolsize"value= "+" />        <!--the minimum number of connections that are kept in the connection pool.  -        < Propertyname= "Minpoolsize"value= "1" />        <!--The number of connections obtained at initialization, and the value should be between Minpoolsize and Maxpoolsize. Default:3 -        < Propertyname= "Initialpoolsize"value= "Ten" />        <!--maximum idle time, unused in 60 seconds, the connection is discarded. If 0, it will never be discarded. default:0 -        < Propertyname= "MaxIdleTime"value= "+" />        <!--when the connection in the connection pool runs out, c3p0 the number of connections that are fetched at one time. Default:3 -        < Propertyname= "Acquireincrement"value= "5" />        <!--the standard parameters of JDBC to control the number of preparedstatements loaded within the data source. However, because the pre-cached statements belong to a single connection instead of the entire connection pool.          So setting this parameter takes into account a variety of factors. If both maxstatements and maxstatementsperconnection are 0, the cache is closed. default:0 -        < Propertyname= "Maxstatements"value= "0" />                 <!--Check for idle connections in all connection pools every 60 seconds. default:0 -        < Propertyname= "Idleconnectiontestperiod"value= "$" />                 <!--defines the number of repeated attempts to obtain a new connection from the database after a failure. Default:30 -        < Propertyname= "Acquireretryattempts"value= "+" />                <!--getting a connection failure will cause any thread that waits for the connection pool to get the connection to throw an exception. However, the data source is still valid and continues to try to get the connection the next time you call Getconnection (). If set to True, the data source will declare broken and permanently shut down after attempting to acquire a connection failure. Default:false -        < Propertyname= "Breakafteracquirefailure"value= "true" />                 <!--Please use it only when you need it because of high performance consumption. If set to true then the validity of each connection submission is officer. We recommend using methods such as Idleconnectiontestperiod or automatictesttable to improve the performance of your connectivity tests. Default:false -        < Propertyname= "Testconnectiononcheckout"value= "false" />            </Bean>

Database connection pools C3P0 and DBCP