I am studying for Spring Core certification and I have some doubt about how correctly answer to this question:
How do you configure a DataSource in Spring? Which bean is very useful
for development?
I think that I do something like this to configure DataSource in a Spring XML configuration file:
<bean id=“dataSource” class=“org.apache.commons.dbcp.BasicDataSource”>
<property name=“url” value=“${dataSource.url}” />
<property name=“username” value=“${dataSource.username}” />
<property name=“password” value=“${dataSource.password}” />
</bean>
<jdbc:initialize-database data-source=“dataSource”>
<jdbc:script location=“classpath:schema.sql” />
<jdbc:script location=“classpath:test-data.sql” />
</jdbc:initialize-database>
So I think that the answered bean is the org.apache.commons.dbcp.BasicDataSource. Is this assertion true or am I missing something?
What exactly represent the declared configuration tag? It is clear for me what it do but what exactly represent? Is it a special bean declaration or what?
Tnx
I believe it has to be helper for creating in memory DB for DEV purposes:
#Bean
#Profile("dev")
public DataSource devDataSource() {
return new EmbeddedDatabaseBuilder()
.setType(EmbeddedDatabaseType.HSQL)
.addScript("classpath:com/bank/config/sql/schema.sql")
.addScript("classpath:com/bank/config/sql/test-data.sql")
.build();
}
XML config:
<jdbc:embedded-database id="dataSource">
<jdbc:script location="classpath:schema.sql"/>
<jdbc:script location="classpath:test-data.sql"/>
</jdbc:embedded-database>
Relevant part of Spring docs.
I don't know much about exams and certification questions :-)
But here is a valid XML datasource config JDBC MySQL
<!-- App's dataSource used by jdbcTemplate,jdbc-user-service and connectController anss so on -->
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/springappdb" />
<property name="username" value="root" />
<property name="password" value="yourpassword" />
</bean>
<!-- jdbcTemplate -->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
<constructor-arg ref="dataSource" />
</bean>
Related
I am using spring 3 but my configuration is xml based in which I am trying to convert my project into annotation based using #configuration annotation.
I am little confused how to add data source entry as #Bean for two below cases
<bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName" value="jdbc/myds" />
</bean>
<bean id="data_source" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
<property name="url" value="url1" />
<property name="username" value="user1" />
<property name="password" value="****" />
</bean>
In the Java Spring bean configuration of dataSrouce, I tried to define init and destroy attributes which call my mysql scripts as initialization and cleanup for unit tests, as the code shown below:
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="destroy" init-method="init">
<property name="destroy">
<value>classpath: mysql_dropuser.sql</value>
</property>
<property name="init">
<value>classpath: mysql_createuser.sql,classpath: mysql_bootstrap.sql</value>
</property>
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=UTF-8" />
</bean>
But I got the error:
Invalid property 'destroy' of bean class.
My question is that how I could define the init and destroy methods in the xml file?
This is how I did it once before, hope this helps:
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/testdb" />
<property name="username" value="testuser" />
<property name="password" value="testuser" />
<property name="initialSize" value="5" />
<property name="maxActive" value="20" />
<property name="maxIdle" value="20" />
<property name="maxWait" value="5000" />
</bean>
<jdbc:initialize-database data-source="dataSource" ignore-failures="ALL">
<jdbc:script execution="INIT" location="classpath:database/schemas/create_testdb.sql" />
<jdbc:script execution="INIT" location="classpath:database/schemas/add_testdata.sql" />
<jdbc:script execution="DESTROY" location="classpath:database/schemas/drop_testdb.sql" />
</jdbc:initialize-database>
It seems like you have already defined init/destroy methods (they are specified via corresponding attributes). And you should also have public void no-argument methods with that names in your class. Properties are a bit different; as usual they are considered as combination of private field and public get/set methods. So in your case at least setter method public void setDestroy(String str) is expected. Please, check your bean's class to meet these conventions. You may also look for 'spring resource' (http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/core/io/Resource.html) injection, since you're trying to provide file paths into you bean.
in my applicationcontext.xml i have this :
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/dashboardsupervisor" />
<property name="username" value="root" />
<property name="password" value="1234" />
</bean>
here i am connecting with my database :
ApplicationContext ctx = new ClassPathXmlApplicationContext(
"applicationContext.xml");
MySQLRdbHelper rdbHelper = (MySQLRdbHelper)
ctx.getBean("ManagerSupervisor");
What is want is to NOT read the password "1234" from my applicationcontext.xml
and read it from some properties file in my local drive .
as this will be running on different machines and every one have different passwords.
Can i achieve this .
thanks
Yes, you can, and the key to this is Springs PropertyPlaceholderConfigurer.
For example, you create a file on your file system called database.properties, containing your password (note, that you can also add more settings to this file, like username, JDBC url, etc).
jdbc.password=1234
Next, you need to declare a PropertyPlaceholderConfigurer bean and point it to the database.properties file:
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>path/to/database.properties</value>
</property>
</bean>
Note that the path is interpreted as a classpath resource, unless it is prefixed with file:.
Finally, replace the configuration of your dataSource bean: replace
<property name="password" value="1234" />
with
<property name="password" value="${jdbc.password}" />
You could use profiles:
GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
ctx.getEnvironment().setActiveProfiles("dev1");
ctx.load("*Context.xml");
ctx.refresh();
<bean id="database1" profile="dev1"/>
<bean id="database2" profile="dev2">
The best way is to create the data source in application server and configure as below in application.xml
<bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName"><value>YourDSName</value></property>
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource" />
</property>
.....
</bean>
Tried to follow the pattern on apache dbcp examples, I understand everything except how and where the database properties come from and in which bean they have to be placed in application context.
I used Spring Data Source instead, but as I recall I configured it in hurry and I remember having difficulties with configuring the original dataSource provided by apache dbcp itself. So I happen to have time to face the problem and fulfill the original intent of using PoolingDataSource.
The reason I used Spring implementation is because it provides means of setting up the parameters to connect to database.
http://static.springsource.org/spring/docs/2.0.x/api/org/springframework/jdbc/datasource/DriverManagerDataSource.html
According to http://commons.apache.org/dbcp/apidocs/org/apache/commons/dbcp/PoolingDataSource.html
There are no methods to populate configuration like url or load driver.
I tried to track it through the object pools etc. , but got really lost.
Replying upfront: Yes, I don't want to use apache basicDataSource.
So now I am returning to the problem and can't really understand where to fetch the parameters? Driver? Url? It seems that url, pw and username are set on connection factory. But where to fetch postgresql driver to be loaded?
Please help to complete the configuration.
(using spring for configuration)
<!-- the one I want to use now -->
<bean id="dataSource" class="org.apache.commons.dbcp.PoolingDataSource">
<constructor-arg><ref bean="pool"/></constructor-arg>
</bean>
<!-- the one I used before as a workaround
<bean id="ds" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="org.postgresql.Driver"/>
<property name="url" value="jdbc:postgresql:postgres"/>
<property name="username" value="magicUserName"/>
<property name="password" value="magicPassword"/>
</bean> -->
<bean id="pool" class="org.apache.commons.pool.impl.GenericObjectPool">
<property name="minEvictableIdleTimeMillis"><value>300000</value </property>
<property name="timeBetweenEvictionRunsMillis"><value>60000</value </property>
</bean>
<bean id="dsConnectionFactory" class="org.apache.commons.dbcp.DataSourceConnectionFactory">
<constructor-arg><ref bean="dataSource"/></constructor-arg>
</bean>
<bean id="poolableConnectionFactory" class="org.apache.commons.dbcp.PoolableConnectionFactory">
<constructor-arg index="0"><ref bean="dsConnectionFactory"/ </constructor-arg>
<constructor-arg index="1"><ref bean="pool"/></constructor-arg>
<constructor-arg index="2"><null/></constructor-arg>
<constructor-arg index="3"><null/></constructor-arg>
<constructor-arg index="4"><value>false</value></constructor-arg>
<constructor-arg index="5"><value>true</value></constructor-arg>
</bean>
<bean id="txManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<tx:annotation-driven transaction-manager="txManager" />
</beans>
I believe we are interested just in the first two, but I included everything just in case.
Seems to be there are many people using workarounds:
http://forum.springsource.org/showthread.php?10772-How-do-I-create-a-org-apache-commons-dbcp-PoolableConnection
You can config as below:
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="url" value="<put database connection url here>" />
<property name="username" value="XXXXXX" />
<property name="password" value="XXXXXXXX" />
<property name="driverClassName" value="<database driver here>" />
</bean>
<bean id="pool" class="org.apache.commons.pool.impl.GenericObjectPool">
<property name="minEvictableIdleTimeMillis"><value>300000</value></property>
<property name="timeBetweenEvictionRunsMillis"><value>60000</value></property>
</bean>
<bean id="dsConnectionFactory" class="org.apache.commons.dbcp.DataSourceConnectionFactory">
<constructor-arg><ref bean="dataSource"/></constructor-arg>
</bean>
<bean id="poolableConnectionFactory" class="org.apache.commons.dbcp.PoolableConnectionFactory">
<constructor-arg index="0"><ref bean="dsConnectionFactory"/></constructor-arg>
<constructor-arg index="1"><ref bean="pool"/></constructor-arg>
<constructor-arg index="2"><null/></constructor-arg>
<constructor-arg index="3"><null/></constructor-arg>
<constructor-arg index="4"><value>false</value></constructor-arg>
<constructor-arg index="5"><value>true</value></constructor-arg>
</bean>
<bean id="pooledDS" class="org.apache.commons.dbcp.PoolingDataSource"
depends-on="poolableConnectionFactory">
<constructor-arg><ref bean="pool"/></constructor-arg>
</bean>
And you can use "pooledDS" (PoolingDataSource) the same any orther DataSource.
Ortherwise, i think you should simply use BacsicDataSource, you still can config number of connections in pool by "initialSize" and "maxActive":
<bean id="basicDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
<property name="removeAbandoned" value="true"/>
<property name="initialSize" value="10" />
<property name="maxActive" value="50" />
</bean>
I have the following partial spring context xml file:
<bean name="template" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource" />
</bean>
<bean name="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassLoader" value="" /> <!-- THIS PROPERTY -->
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3061/my_database" />
<property name="username" value="username" />
<property name="password" value="password" />
<property name="initialSize" value="8" />
</bean>
How do I inject the driverClassLoader property? (I'm using some custom plug-in architecture but not the spring dm server so have to provide a classloader to find the mysql driver)
this apache dbcp classloader bug was just fixed in march 2011.
It may fix your root issue so you don't need to inject the classloader...
https://issues.apache.org/jira/browse/DBCP-333
without this bug fix I don't think the driverClassloader setter was working....
I think you want to use the PropertyPlaceholderConfigurer. Look at section 3.7.2.1 in the Spring 2.0 reference guide.