I am using Weblogic server to host the EJB application.
Now I have written code to lookup Datasource on server side which works fine
and search the Datasource if code look for specific name. See the line no 2 in below code.
dataSource = (DataSource) ic.lookup("jdbc/irisuatDS");
But my problem is I have 4 different environment let say Local, Dev, Stage and production. Is there any way where code can we written for generic DataSource. something like below lines without pointing to specific name.
When I use below piece of code it gives me error.
dataSource = (DataSource)ic.lookup("java:comp/env");
InitialContext ic = new InitialContext();
dataSource = (DataSource) ic.lookup("jdbc/irisuatDS");
dataSource = (DataSource)ic.lookup("java:comp/env");
Please let me know how can I resolve the issue.
Intro I'm writing a web service using JAX-WS, and deploying it in Tomcat. With a lot of difficulties I finally had some code written.
Problem Unfortunately, when trying to run it I get the following error:
Context is read only
Setting I'm writing a web service that queries multiple databases and returns a single result. For that purpose, in the init() method (marked with #PostConstruct), I create a series of DataSources that I add to the context.
This is how I create the pool (based on Tomcat documentation) and after its creation I add it to the context (based on this tutorial):
#PostConstruct
private void init(){
PoolProperties props = new PoolProperties();
props.setUrl("jdbc:postgresql://" + ...);
props.setUsername(...);
props.setPassword(...);
props.setJdbcInterceptors("org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;" +
"org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");
DataSource dataSource = new DataSource();
dataSource.setPoolProperties(propos);
Context ctx = new InitialContext(env);
ctx.bind("java:/comp/env/dbpool", dataSource);
}
And later I use it:
#WebMethod
public Result performQuery(QueryParameters params){
Context ctx = new InitialContext(env);
(DataSource) source = (DataSource) ctx.lookup("java:/comp/env/dbpool");
}
I deploy the web service on a Tomcat 7 server.
Question I understand after Google-ing that I cannot write into the Context on Tomcat. But how else could I solve this? From what I understand about JAX-WS I cannot just have a private variable holding a DataSource, right? I have to pass that DataSource using a Context, right?
The InitialContext is writable from the Tomcat code only, not from your client code. You must add your DataSource to your context.xml and it'll work.
I have configured MysqlDataSource in tomcat using this link.I have written junit test cases.when am i calling below connection from junit it throws following errors.
javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial
I have used following code
class DataConnection {
private static DataSource dataSource;
public DataConnection() {
try {
Context ctx = new InitialContext();
dataSource = (DataSource)ctx.lookup("java:comp/env/jdbc/test");
} catch (NamingException e) {
e.printStackTrace();
}
}
public static Connection getConnection() throws SQLException {
new DataConnection();
Connection con=dataSource.getConnection();
return con;
}
}
How to call tomcat from junit? How to achieve this?
The code you give gets the database connection from JNDI, e.g. when running in tomcat from the container. However, for Unit Tests (assuming that's what you use JUnit for) I'd rather suggest to use "dependency injection" - e.g. explicitly pass a database connection to the code under test or manually set it up before the test runs.
There's no need to rely on JNDI for executing your tests: That's not what you want to test, instead, you want to just verify that your actual code is running correctly.
You don't need any fancy library (e.g. spring) for dependency injection, just a slightly adjusted architecture. This will greatly enhance the testability of your application and lower the execution time of your tests.
(This is based on my assumptions of your situation based on the little bit of information that you give in your question)
Give TomcatJNDI a try. It is based on embedded Tomcat but initializes only Tomcat's JNDI environment without starting a server. So you can access all your resources as configured in Tomcat's configuration files in tests or from within any Java SE application. The API is simple. For instance to get a DataSource declared in context.xml:
TomcatJNDI tomcatJNDI = new TomcatJNDI();
tomcatJNDI.processContextXml(contextXmlFile);
tomcatJNDI.start();
Then you can lookup the DataSource as usual
DataSource ds = (DataSource) InitialContext.doLookup("java:comp/env/path/to/datasource")
More information about TomcatJNDI can be found here.
I am new to setting up JNDI resources and setting up JNDI resources in Tomcat.
I inherited a servlet application. It runs on a test server via WebLogic. The servlet application accesses its database resource in the following way:
ctx = new InitialContext();
ds = (javax.sql.DataSource)ctx.lookup("myDataBaseName");
conn = ds.getConnection();
When I tried that in a test JSP it doesn't work. I get
javax.naming.NameNotFoundException: Name myDataBaseName is not bound in this Context
However I was able to make the test JSP work if I altered the test JSP code thus:
ctx = new InitialContext();
Context envContext = (Context)ctx.lookup("java:/comp/env");
ds = (DataSource)envContext.lookup("myDataBaseName");
conn = ds.getConnection();
I have this entry in TOMCAT_HOME/conf/context.html ( I'm just using it as a dev environment on my box )
<Resource name="myDataBaseName"
auth="Container"
type="javax.sql.DataSource"
driverClassName="oracle.jdbc.OracleDriver"
url="jdbc:oracle:thin:#blahblahblah:1521:database3"
username="joeuser"
password="password"
maxActive="20"
maxIdle="30"
maxWait="-1"/>
</Context>
And I have this in my TOMCAT_HOME/conf/web.xml:
<resource-ref>
<res-ref-name>myDataBaseName</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
I read about 10 stackoverflow pages on related problems, but I am not familiar enough with setting up JNDI resources to abstract those solutions to my problem.
How can I change the way I have Tomcat 7 set up to allow the existing servlet application to access its database as "myDatabaseName"? I don't have the option of altering the code in the servlet application or altering the way WebLogic is set up on the test server.
I need to alter the way my copy of Tomcat 7 is set up on my computer ( for a dev environment ) to allow the servlet application to access its database in the style of the first chunk of quoted code at the top of this post.
I see 2 possibilities here:
Implement a InitialContextFactory and make it available to tomcat (via system property), so that new InitialContext() gives you a context the lookup would work on.
or
Bind the data source to another place in the JNDI, which actually works although it is neither recommended nor documented (tomcat FM states the tree being read-only which only seems to apply to the subtree java:/comp/env):
Context ctx = new InitialContext();
DataSource ds = (DataSource) ctx.lookup("java:/comp/env/myDataBaseName");
ctx.bind("myDataBaseName", ds);
With the configuration that you provided you should be able to do the following:
ctx = new InitialContext();
ds = (DataSource)ctx.lookup("java:/comp/env/myDataBaseName");
conn = ds.getConnection();
I'm trying to follow Sun's JDBC tutorial at http://java.sun.com/docs/books/tutorial/jdbc/basics/connecting.html
It gives the following example code:
DataSource ds = (DataSource) org.apache.derby.jdbc.ClientDataSource()
ds.setPort(1527);
ds.setHost("localhost");
ds.setUser("APP")
ds.setPassword("APP");
Connection con = ds.getConnection();
This code doesn't compile because the DataSource interface has none of these methods, except for the getConnection() method invoked last.
(Here's the javadoc: http://java.sun.com/javase/6/docs/api/javax/sql/DataSource.html)
What am I missing?
Edit:
I'm actually trying to connect to MySQL (com.mysql.jdbc) and I can't find the javadoc for that. I'll accept an answer that points me to either:
1) documentation for com.mysql.jdbc regarding a DataSource that I can understand, or
2) gives an example to follow for what the tutorial's code should be, for any database.
One thing you might want to look at is the Commons DBCP project. It provides a BasicDataSource that is configured fairly similarly to your example. To use that you need the database vendor's JDBC JAR in your classpath and you have to specify the vendor's driver class name and the database URL in the proper format.
Edit:
If you want to configure a BasicDataSource for MySQL, you would do something like this:
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUsername("username");
dataSource.setPassword("password");
dataSource.setUrl("jdbc:mysql://<host>:<port>/<database>");
dataSource.setMaxActive(10);
dataSource.setMaxIdle(5);
dataSource.setInitialSize(5);
dataSource.setValidationQuery("SELECT 1");
Code that needs a DataSource can then use that.
DataSource is vendor-specific, for MySql you could use MysqlDataSource which is provided in the MySql Java connector jar:
MysqlDataSource dataSource = new MysqlDataSource();
dataSource.setDatabaseName("xyz");
dataSource.setUser("xyz");
dataSource.setPassword("xyz");
dataSource.setServerName("xyz.yourdomain.com");
Basically in JDBC most of these properties are not configurable in the API like that, rather they depend on implementation. The way JDBC handles this is by allowing the connection URL to be different per vendor.
So what you do is register the driver so that the JDBC system can know what to do with the URL:
DriverManager.registerDriver((Driver) Class.forName("com.mysql.jdbc.Driver").newInstance());
Then you form the URL:
String url = "jdbc:mysql://[host][,failoverhost...][:port]/[database][?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]"
And finally, use it to get a connection:
Connection c = DriverManager.getConnection(url);
In more sophisticated JDBC, you get involved with connection pools and the like, and application servers often have their own way of registering drivers in JNDI and you look up a DataSource from there, and call getConnection on it.
In terms of what properties MySQL supports, see here.
EDIT: One more thought, technically just having a line of code which does Class.forName("com.mysql.jdbc.Driver") should be enough, as the class should have its own static initializer which registers a version, but sometimes a JDBC driver doesn't, so if you aren't sure, there is little harm in registering a second one, it just creates a duplicate object in memeory.
use MYSQL as Example:
1) use database connection pools: for Example: Apache Commons DBCP , also, you need basicDataSource jar package in your classpath
#Bean
public BasicDataSource dataSource() {
BasicDataSource ds = new BasicDataSource();
ds.setDriverClassName("com.mysql.jdbc.Driver");
ds.setUrl("jdbc:mysql://localhost:3306/gene");
ds.setUsername("root");
ds.setPassword("root");
return ds;
}
2)use JDBC-based Driver it is usually used if you don't consider connection pool:
#Bean
public DataSource dataSource(){
DriverManagerDataSource ds = new DriverManagerDataSource();
ds.setDriverClassName("com.mysql.jdbc.Driver");
ds.setUrl("jdbc:mysql://localhost:3306/gene");
ds.setUsername("root");
ds.setPassword("root");
return ds;
}
I think the example is wrong - javax.sql.DataSource doesn't have these properties either. Your DataSource needs to be of the type org.apache.derby.jdbc.ClientDataSource, which should have those properties.
The javadoc for DataSource you refer to is of the wrong package. You should look at javax.sql.DataSource. As you can see this is an interface. The host and port name configuration depends on the implementation, i.e. the JDBC driver you are using.
I have not checked the Derby javadocs but I suppose the code should compile like this:
ClientDataSource ds = org.apache.derby.jdbc.ClientDataSource()
ds.setHost etc....
For postgres, the below works. I actually used it in integ tests. I guess there should be some more consideration for production usage.
PGSimpleDataSource ds = new PGSimpleDataSource() ;
ds.setServerName( "localhost" );
ds.setDatabaseName( "your_db_name_here" );
ds.setUser( "scott" );
ds.setPassword( "tiger" );
The class is bundled in the postgres jdbc driver.
The original stackoverflow post i followed: https://stackoverflow.com/a/45091982/3877642