I am learning Spring Boot using open-source projects and have stumbled upon their demo project — PetClinic. It has two possible databases configured: MySQL & HSQLDB, it uses the latter by default.
So I was able to launch the project look at it on localhost and can see that the DB (HSQLDB) is being populated but I was unable to set up a connection through the Intellij IDEA because the project does not specify the path that allows to see the contents of this in-memory DB.
Can anyone please tell me, what am I missing in the process of establishing the connection to HSQLDB here?
Thanks!
You can't connect to an in-memory instance of HSQLDB from another process.
The main drawback [of in-memory mode] is that it is not possible by default to connect to
the database from outside your application. As a result you cannot
check the contents of the database with external tools such as
Database Manager while your application is running.
If you want to do this, you need to run HSQL as a server. More details about how to run it in server mode can be found here.
Related
I have created a Service running on Tibco, containing a JDBC-enabled process within it, and tested it successfully. The database server is MySQL, and is hosted remotely. When connecting to the remote DB from the service hosted on my machine, the SQL is executed well, but after building the Tibco EAR file and deploying to another external machine, then trying to access the same remote DB server using the same credentials, the external machine returns the below error upon returning:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'OPTION SQL_SELECT_LIMIT=DEFAULT' at line 1
So, a few questions:
What could be the cause of the above error, given the DB being accessed is the exact same one, using same SQL query, but from different machines?
Is the JDBC driver used for development compiled as part of the packaged EAR file?
Does the JDBC driver being used in a Tibco Process depend on the Tibco service installed or on the packaged EAR file?
Am asking from a learner PoV as am currently picking up Tibco
It looks like jdbc driver issue. You may have different mysql driver version in tibco designer and BusinessWorks.
You don't need to add jdbc driver to your ear package.
Please note that you can specify mysql driver in your package classpath. In tibco Administrator PackageName->Configuration->ServerSettings->Prepend to ClassPath or Append to Class path.
You can also try to copy the driver from your tibco designer(in BW5 it's in \tibco\bw\5.11\lib\
) to the BusinessWorks classpath
I have a Spring Boot application (version 1.5.1.RELEASE) and I am using spring-boot-starter-data-jpa as a dependency to manage my database. I am using postgres as my database and configured it using the below properties.
spring.datasource.url=${POSTGRES_URL}
spring.datasource.username=${POSTGRES_USER}
Now when I run my tests which are almost 120, I get too many client already open error for abou 10 test cases while starting the test case itself and it fails.(remaining 100 test cases pass with success as they are able to get a connection to database)
First thing I did is increased my default postgres max connections count from 100 to 200 in the postgres server config file and my tests pass successfully after this change.
Now I investigated a bit and tried setting the parameters for connection pooling properties such as :
spring.datasource.tomcat.max-active=200
spring.datasource.tomcat.test-on-borrow=true
spring.datasource.tomcat.max-wait=10000
However these properties do not work and the tests fails again giving the same error as above. I tried reading from multiple different blogs and spring documentation for setting the connection pool properties but did not find what might be going wrong with me.
I also think that if I set the above property spring.datasource.tomcat.max-active to 100 connections it should work with the help of tomcat jdbc pooling as i think in current scenario it is trying to open a new connection to database for each test case and I am in a fear that this same scenario might happen when I deploy this code to production environment and a new connection will be opened to the database for each request.
Does anyone have faced this problem before or is there something wrong I am doing.
Thanks in advance for the help.
Try upgrading Spring boot version, 1.5.10-RELEASE is the current version.
Also, I found the connection pool properties for my application were not being applied when the property prefix tomcat was included. If you are still having issues try removing that.
i.e.
spring.datasource.tomcat.max-active=200
Becomes
spring.datasource.max-active=200
See https://artofcode.wordpress.com/2017/10/19/spring-boot-configuration-for-tomcats-pooling-data-source
I am using in memory hsqldb in my spring boot project. Here is a sample of my appliction.properties
spring.datasource.url=jdbc:hsqldb:mem
spring.datasource.username=
spring.datasource.password=
spring.datasource.driver-class-name=org.hsqldb.jdbc.JDBCDriver
When I start my application, it creates couple of files like mem.script, mem.log in my project home directory.
mem.log has all the sql statements it has excuted on the database. And it gets updated whenever some action is triggered from my repository class. Functionality as a whole is working, I can even query from this hsqldb and it works.
But for some debugging purpose I want to connect to this db through some db client (DBVisualizer). When I tried connecting(DB Type : HSQLDB Embedded) using this mem.log file, I was successfully connected, but cannot see any of my tables there.
I even tried setting up a server in my application as mentioned here,
How to start HSQLDB in server mode from Spring boot application
Even in this case I can connect from DBVisualizer(DB Type : HSQLDB Server) but cannot see any tables.
Please let me know if I am missing something.
Thanks
First of all, the url you are using is too similar to an all-in-memory database with no files (jdbc:hsqldb:mem:anyname) but it is not an in-memory URL.
Follow the the instructions for the server mode in the question you linked to. Report your version of the configuration if you cannot see the tables. Note the configuration parameters that I quote below:
<prop key="server.database.0">mem:testdb</prop>
<prop key="server.dbname.0">testdb</prop><!--DB name for network connection-->
and connect with this URL from DBVisualiser
jdbc:hsqldb:hsql://localhost/testdb
I am not able to connect to my HSQLDB database from RazorSQL. I am only having this issue when I am running in Server mode and when I am attempting to connect from RazorSQL.
Using the same URL from Eclipse Data Source Explorer, and from the application itself (which is a Hibernate 5.2.7 application), I am able to successfully connect to my database at the URL "jdbc:hsqldb:hsql://localhost/SudokuHibernate". Since I am running it in Server mode, I am able to connect concurrently.
(Note: I don't have to have multiple concurrent connections, but it make debugging easier). The database is being run in Server mode from the command line via ...
java -cp ../libs/hsqldb-2.3.4/hsqldb/lib/hsqldb.jar org.hsqldb.server.Server --database.0 file:/Users/arick/src/databases/SudokuHibernate --dbname.0 SudokuHibernate
When attempting to connect from RazorSQL, the database console shows the error message. "org.hsqldb.HsqlException: Client driver version greater than '2.1.0.0' is required. The HSQLDB server version is '2.3.4'".
Note: This is a different question then a similar StackOverflow question, as all of my own configuration files are explicitly referencing the same JDBC driver, from the same jar file. However, as pointed out by Fred T, the reference to '2.1.0.0', by HSQLDB, is somewhat misleading. It is really just saying that the client and the server have two different versions of the JDBC driver.
At the same time that the database is throwing a mismatched version error, RazorSQL displays a dialog box with the error message:
ERROR: An error occurred while trying to make a connection to the database:
JDBC URL: jdbc:hsqldb:hsql://localhost/SudokuHibernate
connection exception: connection failure: java.io.EOFException
Below is my RazorSQL connection profile.
RazorSQL Profile
Driver Location: /Users/arick/src/libs/hsqldb-2.3.4/hsqldb/lib/hsqldb.jar
JDBC URL: jdbc:hsqldb:hsql://localhost/SudokuHibernate
As was inferred by Mark Rotteveel, the answer is similar to a related question about how to get Eclipse and Maven to talk to a HSQLDB server that is running in standalone server mode.
In that case, Fred Toussi, the lead on the HSQLDB project, pointed out the answer was to modify the configuration file, that is used in Eclipse and Maven, to pull in the appropriate version of the HSQLDB JDBC jar file, and also to make sure the jar file didn't appear anywhere else on the classpath. Maven uses a pom.xml file for configuration; so what was needed was make sure that the correct version of the HSQLDB was defined in the project's pom.xml file.
In my situation, the RazorSQL product that I was using, just happens to use HSQLDB as the embedded database for itself. If I had been using any other Java database, I may not have had this problem. But, since the RazorSQL product had already loaded its own version of the HSQLDB jar file, it didn't matter what I specified in my configuration for the database connection. It wasn't going to work.
No matter how I changed my driver profile, or my connection profile, the only version of the HSQLDB jar file that was going to get loaded, was the original jar file, that was already in use by RazorSQL, and that came with RazorSQL. (Note: This is true, unless RazorSQL gets fancy, and it decides to use a different classloader, and some of the other tricks that are commonly used by Java applications servers to solve these problems).
As per suggestion from Dan Richardson, from RazorSQL, the actual answer was not by modifying my configurations, but by changing the contents of the RazorSQL distribution itself. I needed to replace the jar file that is used by the RazorSQL application. This jar file is in Mac application folder for RazorSQL. This location is typically at /Applications/RazorSQL.app/Contents/Java/drivers/hsqldb.
(Note: If you are not familiar with how to open a Mac app folder, you just right-click on the RazorSQL folder name in the /Applications directory and use the "Show Package Contents" menu option). In my case, I renamed the original hsqldb.jar file to be hsqldb_2.3.2.jar file, and then I copied in the last distribution of the hsqldb.jar.
I am trying to setup a struts project locally. One way I know to set up JDBC settings as to go to administrative console of websphere and create JDBC provider and JNDI and all. But is there any other way to do in the code itself?
There is some resource reference in web.xml. I am totally new to struts.Please help.
DataSourceAlias
javaxsql.Data...... etc etc
If you configured for WAS 6.1and configuration is good you need to stop and start nodeAgents for the changes to get propagated and test the jdbc connection after restarting.....if it was WAS 8 they will be propagated automatically that means you configured improperly