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--- java:thelastpacketsuccessfullyreceivedfromserver [2013/10/02 07:25] – [My architecture] rlunaro
+++ java:thelastpacketsuccessfullyreceivedfromserver [2022/12/02 21:02] (current) – external edit 127.0.0.1
@@ Line 13: / Line 13: @@
   * Mysql worked perfectly
   * There wasn't a network error
-  * So... what the problem were???
+  * So... were the problem is???
 ==== My architecture ====
@@ Line 275: / Line 275: @@
 </code>
-**An this is wrong.** The [[http://docs.spring.io/spring/docs/2.5.x/api/org/springframework/orm/hibernate3/HibernateTemplate.html|HibernateTemplate]] object must be declared singleton. This saves lots of session objects and keep them alive because they are always been called across the application.
+**An this is wrong.** The [[http://docs.spring.io/spring/docs/2.5.x/api/org/springframework/orm/hibernate3/HibernateTemplate.html|HibernateTemplate]] object must be declared singleton (maybe "session" in a web application to avoid multithreading issues). This saves lots of session objects and keep them alive because they are always been called across the application.
 However, I am starting to think that HibernateTemplate doesn't close properly it's Session objects. If this were the case, it will explain why when I release my HibernateTemplate objects the corresponding session objects weren't released and closed.
@@ Line 322: / Line 322: @@
+===== My final configuration of Spring =====
+First, define C3P0 datasource:
+<code>
+	  <!--
+	  A better datasource: it gives a new connection each time
+	  is requested.
+	  -->
+	  <bean id="dataSource"
+	        class="com.mchange.v2.c3p0.ComboPooledDataSource"
+	        destroy-method="close"
+	        scope="singleton">
+      <!--
+      To test a connection:
+      mysql -h HOSTNAME -u USERNAME -p
+      and aftwerwards introduce the password when requested
+       -->
+      <property name="driverClass" value="com.mysql.jdbc.Driver"/>
+      <property name="jdbcUrl"     value="jdbc:mysql://${mysql-server}:${mysql-port}/${mysql-database}"/>
+      <property name="user"        value="${mysql-user}"/>
+      <property name="password"    value="${mysql-password}"/>
+      <!--
+      Recommended values for maxPoolSize and minPoolSize:
+. get value of max available connections of your
+             database issuing command 'show variables like "max_connections";'
+. this will be the upper limit for maxPoolSize: you shouldn't
+             reach never this limit
+. check out with show processlist the active connections
+             to the database: this will help to determine the available
+             connections for your application:
+             (show processlist) - (show variables like max_connections)
+. it is advisable to identify how many DAO objects will be
+             issuing sentences to the database at the same time. Ok,
+             make a rough stimation. Say that this value will be
+. A good and steady value for maxPoolSize can
+             be 40 (four times).
+       -->
+			<property name="maxPoolSize"         value="10"/>
+			<property name="minPoolSize"         value="5"/>
+			<!--
+			checkoutTimeout mits how long a client will wait for a
+			Connection, if all Connections are checked out and one
+			cannot be supplied immediately. In milliseconds.
+			http://www.mchange.com/projects/c3p0/#checkoutTimeout
+			-->
+			<property name="checkoutTimeout"     value="10000"/>
+			<property name="acquireIncrement"    value="1"/>
+			<property name="idleConnectionTestPeriod" value="100"/>
+			<!-- property name="preferredTestQuery"  value="select 1"/ -->
+			<!--
+			testConnectionOnCheckout is not recommended because it
+			checks the connection before give it to hibernate. In a
+			paranoid environment could fix some problems
+			-->
+			<!-- property name="testConnectionOnCheckout" value="true"/-->
+			<!--
+			debugUnreturnedConnectionStackTraces prints a stack trace when
+			a connection that is given to hibernate reachs its timeout value.
+			This could help to debug cases when a connection is taken and
+			not released in a certain amount of time
+			http://www.mchange.com/projects/c3p0/#debugUnreturnedConnectionStackTraces
+			-->
+			<!-- property name="debugUnreturnedConnectionStackTraces" value="true"/-->
+			<!--
+			unreturnedConnectionTimeout is the silver bullet for a problem in
+			a greedy application (in terms of sessions). It will count how long
+			hibernate has taken a connection, and if reachs a timeout, c3p0 will
+			replace this connection with a fresh session, avoiding the problem
+			of the database may close opened for much time
+			http://www.mchange.com/projects/c3p0/#unreturnedConnectionTimeout
+			-->
+			<!--property name="unreturnedConnectionTimeout" value="100"/-->
+	  </bean>
+</code>
+Second, the hibernateTemplate and jdbctemplate objects of spring will be available accross the application.
+**Beware!!! If you are developing a web application, these should be session instead of singleton!!!**
+<code xml>
+	  <bean id="simpleJdbcTemplate"
+	        class="org.springframework.jdbc.core.simple.SimpleJdbcTemplate"
+	        scope="singleton">
+	    <constructor-arg ref="dataSource"/>
+	  </bean>
+    <bean id="hibernateTemplate"
+          class="org.springframework.orm.hibernate3.HibernateTemplate"
+          scope="singleton">
+        <property name="sessionFactory" ref="sessionFactory"/>
+    </bean>
+</code>
+Finally, the sessionFactory:
+<code xml>
+    <bean id="sessionFactory"
+          class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"
+          scope="singleton">
+        <property name="dataSource" ref="dataSource"/>
+        <property name="annotatedClasses">
+            <list>
+                <value>com.mapfre.dga.mercurio.entity.Detail</value>
+                <value>com.mapfre.dga.mercurio.entity.Indicator</value>
+                <value>com.mapfre.dga.mercurio.entity.Period</value>
+                <value>com.mapfre.dga.mercurio.entity.Struct</value>
+                <value>com.mapfre.dga.mercurio.entity.Valoration</value>
+                <value>com.mapfre.dga.mercurio.entity.Version</value>
+            </list>
+        </property>
+        <property name="hibernateProperties">
+            <props>
+                <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
+                <!-- for debug, put these values to "true" -->
+                <prop key="hibernate.show_sql">${show-sql-in-hibernate}</prop>
+                <prop key="hibernate.format_sql">${format-sql-in-hibernate}</prop>
+                <!--
+                Possible values for this are:
+                     on_close : legacy behavior. The session gets the connection when
+                                the first time it requires it and release it when it's
+                                destroyed
+                     after_transaction :
+                                session is released after Transaction issues a commit or
+                                rollback
+                     after_statement :
+                                connection is released after execution of every statement,
+                                BUT it will keep the connection open if the object
+                 -->
+                <!-- prop key="hibernate.connection.release_mode">after_statement</prop -->
+            </props>
+        </property>
+    </bean>
+</code>
+I've put plenty of comments of useful configuration parameters and lots of information, just in case.
+===== Resources =====
+http://www.mchange.com/projects/c3p0/
 ~~DISQUS~~