I have a HSQL database which Spring automatically creates for me:
<jdbc:embedded-database id="dataSource" type="HSQL">
<jdbc:script location="classpath:scheme.sql" /
</jdbc:embedded-database>
And now I want to connect to this database. My question is how to do this, because I don't known which address I should use.
This embedded HSQL database is all-in-memory and in-process, therefore accessible only from the Spring Java process. If you want to access the database from another tool as well, for example to check the contents with a database manager, you can start an HSQLDB server with an all-in-memory instance, then connect to the server from Spring and other tools.
This is covered in the HSQLDB Guide http://hsqldb.org/doc/2.0/guide/listeners-chapt.html
The server is started with this command:
java -cp ../lib/hsqldb.jar org.hsqldb.Server --database.0 mem:test --dbname.0 test
You need to create a Spring data source with username "SA" and password "". The database driver and URL (from the same machine) to configure the Spring data source are:
org.hsqldb.jdbcDriver
jdbc:hsqldb:hsql://localhost/test
I recomend you to use external Database, but just in case if you want to use HSQL, then this may will help you http://java.dzone.com/articles/spring-3-makes-use-embedded-easy
Embedded-database is an in memory DB and Spring supports HSQL, H2, and Derby . You could go to their respective site for the connection details .
For H2 see here .
For HSQL see here and here.
As far as I understand , the
<jdbc:embedded-database id="dataSource" type="HSQL">
<jdbc:script location="classpath:scheme.sql" /
</jdbc:embedded-database>
uses an in-memory DB and so is not accessible externally . You'll be able to access this within the same VM and same class loader .
You can connect to the embedded database in the normal fashion, (SQL Developer, SQL Explorer etc); I used my debugger to look at the URL property in the embedded database bean I created with Spring, in your case dataSource. I would think your url would be something along the lines of jdbc:hsqldb:mem:dataSource.
For some people a sufficient solution would be to use the h2 console - as described here:
spring boot default H2 jdbc connection (and H2 console)
You must only remember to set hsqldb drivers where needed. This way the database doesn't have to be started separately. You also don't have to install any additional software to browse it.
you can do like this
final ApplicationContext ctx = new ClassPathXmlApplicationContext("dao-context.xml");
final DataSource dataSource = (DataSource)ctx.getBean("dataSource");
final Connection conn = dataSource.getConnection();
Related
I got to know Java spring JPA a couple days ago and there is one question which really makes me confused.
As I create a repository and use 'save()' method to save some objects into it. How does it know what type of database I am using and which local location to save.
I know I can config database (h2) like:
spring.datasource.url=jdbc:h2:mem/mydb
Then JPA will know: ok you are using h2 database and url is "jdbc:h2:mem/mydb"
However, some people said this config is not mandatory. If without this config, how does JPA knows which database I gonna use?
From the spring-boot documentation:
You should at least specify the URL by setting the spring.datasource.url property. Otherwise, Spring Boot tries to auto-configure an embedded database.
The following class is responsible for providing default settings for embedded DB: org.springframework.boot.autoconfigure.jdbc.DataSourceProperties
public String determineDatabaseName() {
...
if (this.embeddedDatabaseConnection != EmbeddedDatabaseConnection.NONE) {
return "testdb";
}
...
}
This answer can also be helpful: Where does the default datasource url for h2 come from on Spring Boot?
I am using embedded jetty (group: 'org.eclipse.jetty', name: 'jetty-webapp', version: '9.4.27.v20200227') and I am trying to programmatically setup it to use JDBC for session storage. All the documentation/examples I can find is about standalone jetty.
Do you know how to setup it?
I don't know all that much about JDBC or session storage, but looking at the documentation Persistent Sessions: JDBC for standalone jetty, it is telling you to enable the module session-store-jdbc. By looking at session-store-jdbc.mod you can see that it uses etc/sessions/jdbc/session-store.xml and these XML files can be directly translated into java code.
So it looks like its adding a JDBCSessionDataStoreFactory as a bean onto the server. So some equivalent code that you could try would look something like:
// Configure a JDBCSessionDataStoreFactory.
JDBCSessionDataStoreFactory sessionDataStoreFactory = new JDBCSessionDataStoreFactory();
sessionDataStoreFactory.setGracePeriodSec(3600);
sessionDataStoreFactory.setSavePeriodSec(0);
sessionDataStoreFactory.setDatabaseAdaptor(...);
JDBCSessionDataStore.SessionTableSchema schema = new JDBCSessionDataStore.SessionTableSchema();
schema.setAccessTimeColumn("accessTime");
schema.setContextPathColumn("contextPath");
// ... more configuration here
sessionDataStoreFactory.setSessionTableSchema(schema);
// Add the SessionDataStoreFactory as a bean on the server.
server.addBean(sessionDataStoreFactory);
I am working on a program which uses memory DB(in my case, it is apache derby, is included in jdk 1.6 and further).
I can set resources like dataSource and sqlSession bean to 'root-context.xml', but do not know how to create DB and table.
If table and DB are already exist, I can do CRUD via usual way. However, this time I should make a DB and new Table on first time. I already tried Maker Class and put 'init-method' to create DB and table before was is uploaded, but it does not work.
How can I make a Spring was program which makes Memory DB and Table before running?
P.S.
I really like to use CRUD in Spring way like SqlSessionTemplate or annotation. But almost of derby sample uses PreparedStatement or Statement. If you have any good sample links what I am looking for, share please. Thanks :D
You need to use the jdbc namespace which includes an embedded-database tag with support for Derby out of the box. The tag takes nested script tags to define scripts to run (they are run in the order declared).
<jdbc:embedded-database id="myDB" type="DERBY" >
<jdbc:script location="classpath:sql/schema.sql"/>
<jdbc:script location="classpath:sql/data.sql"/>
</jdbc:embedded-database>
I try to set up a local development infrastructure and I want to use HSQLDB as a datasource with my WAS 6.1. I already know that I have to use Apache DBCP to get a connection pooling, but I'm stuck when my application tries to get the first connection.
What I've done
In WAS I created a JDBC provider with the class org.apache.commons.dbcp.cpdsadapter.DriverAdapterCPDS and removed everything from the classpath input field. Then I put commons-dbcp.jar, commons-pool.jar and hsqldb.jar in MYAPPSERVERDIRECTORY/lib/ext.
Then I created a new datasource with that provider. I added the following custom properties:
driver=org.hsqldb.jdbc.JDBCDriver
url=jdbc:hsqldb:file:///C:/mydatabase.db;shutdown=true
user=SA
password=
My Problem
When I run my application and the first connection to the database is made, I get the following exception:
---- Begin backtrace for Nested Throwables
java.sql.SQLException: No suitable driverDSRA0010E: SQL-Status = 08001, Fehlercode = 0
at java.sql.DriverManager.getConnection(DriverManager.java:592)
at java.sql.DriverManager.getConnection(DriverManager.java:196)
at org.apache.commons.dbcp.cpdsadapter.DriverAdapterCPDS.getPooledConnection(DriverAdapterCPDS.java:205)
at com.ibm.ws.rsadapter.spi.InternalGenericDataStoreHelper$1.run(InternalGenericDataStoreHelper.java:918)
at com.ibm.ws.security.util.AccessController.doPrivileged(AccessController.java:118)
at com.ibm.ws.rsadapter.spi.InternalGenericDataStoreHelper.getPooledConnection(InternalGenericDataStoreHelper.java:955)
at com.ibm.ws.rsadapter.spi.WSRdbDataSource.getPooledConnection(WSRdbDataSource.java:1437)
at com.ibm.ws.rsadapter.spi.WSManagedConnectionFactoryImpl.createManagedConnection(WSManagedConnectionFactoryImpl.java:1089)
at com.ibm.ejs.j2c.FreePool.createManagedConnectionWithMCWrapper(FreePool.java:1837)
at com.ibm.ejs.j2c.FreePool.createOrWaitForConnection(FreePool.java:1568)
at com.ibm.ejs.j2c.PoolManager.reserve(PoolManager.java:2338)
at com.ibm.ejs.j2c.ConnectionManager.allocateMCWrapper(ConnectionManager.java:909)
at com.ibm.ejs.j2c.ConnectionManager.allocateConnection(ConnectionManager.java:599)
at com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource.getConnection(WSJdbcDataSource.java:439)
at com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource.getConnection(WSJdbcDataSource.java:408)
Any tips on this? I suspect I'm using a wrong class from hsqldb, or maybe my JDBC url is wrong...
In the example given in BDCP docs, the org.hsqldb.jdbcDriver class is used as the driver. The org.hsqldb.jdbc.JDBCDriver is supported only in HSQLDB 2.x, but the other class is supported by all versions of HSQLDB.
Seems like a simple task. I have a webapp which requires a database connection. I'd like to be able to drop an updated .war file on this app server and load a new version without having to re-edit an applicationConfig.xml file to specify the database connection parameters for production.
Is using the container to setup the data source and then referencing it from JNDI the preferred way to go? I think it is cleaner having it all defined in the spring .xml file, but I can't come up with a clean way to allow the production password to be set only once as we roll out new versions.
So, how do you specify your database connection information in a spring application so that you can upgrade it without having to re-edit the files?
If you use JNDI, how do you handle setting up of your tests since the JNDI is not going to be available outside of the container?
Thanks!
The typical way to externalize database connection properties is to store them in a .properties file and load using <context:property-placeholder .../> . Then you can have different .properties files for testing and production.
If you choose JNDI, you can use a Spring's mock JNDI support for testing.
One approach is for your Spring configuration file to be composed of fragments related to specific layers in your application.
One such fragment could contain your DataSource defintion. For production, this fragment would use a jee:jndi-lookup. And then for test, have a different fragment would use a DriverManagerDataSource ?
Update:
If you want to change the datasource after deployment, then you can use this technique, along with changing the which datasource is injected into your other beans using a PropertyPlaceholderConfigurer as explained in an old post I wrote
eg:
<bean class="foo.bar.SomeClassNeedingDataSource"">
<property name="dataSource" ref="${the.datasource.to.inject}" />
</bean>
<jee:jndi-lookup id="jndiDataSource" ... />
<bean id="driverManagerDataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
...
</bean>
# the properties file
the.datasource.to.inject = jndiDataSource
#the.datasource.to.inject = driverManagerDataSource