Develop Reference

springboot with GCP BigTable

i am a new bee to GCP and trying to develop springboot rest api that connects to GCP Bigtable, do we have a quickstart guide that helps in development.

Yup, there is. Check out this link to get started. You need the Java client library.
https://cloud.google.com/bigtable/docs/reference/libraries#client-libraries-install-java
for Maven:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>libraries-bom</artifactId>
<version>26.1.4</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-bigtable</artifactId>
</dependency>
Then check this for usage:
https://cloud.google.com/bigtable/docs/reference/libraries#client-libraries-usage-java
import com.google.api.gax.rpc.NotFoundException;
import com.google.cloud.bigtable.data.v2.BigtableDataClient;
import com.google.cloud.bigtable.data.v2.BigtableDataSettings;
import com.google.cloud.bigtable.data.v2.models.Row;
import com.google.cloud.bigtable.data.v2.models.RowCell;
public class Quickstart {
public static void main(String... args) {
String projectId = args[0]; // my-gcp-project-id
String instanceId = args[1]; // my-bigtable-instance-id
String tableId = args[2]; // my-bigtable-table-id
quickstart(projectId, instanceId, tableId);
}
public static void quickstart(String projectId, String instanceId, String tableId) {
BigtableDataSettings settings =
BigtableDataSettings.newBuilder().setProjectId(projectId).setInstanceId(instanceId).build();
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(settings)) {
System.out.println("\nReading a single row by row key");
Row row = dataClient.readRow(tableId, "r1");
System.out.println("Row: " + row.getKey().toStringUtf8());
for (RowCell cell : row.getCells()) {
System.out.printf(
"Family: %s Qualifier: %s Value: %s%n",
cell.getFamily(), cell.getQualifier().toStringUtf8(), cell.getValue().toStringUtf8());
}
} catch (NotFoundException e) {
System.err.println("Failed to read from a non-existent table: " + e.getMessage());
} catch (Exception e) {
System.out.println("Error during quickstart: \n" + e.toString());
}
}
}

Invalid URL scheme name "http-remoting" occurring when running application jar

I am using one of the JBoss JMS quickstart projects (HelloWorld-JMS) which uses JMS to write to a message queue. The queue has been defined in the JBoss XML configuration file. Our application runs perfectly fine when we run it from the IDE. However, when we package it as a JAR, we start seeing the exception:
SEVERE: Exception NamingException: javax.naming.InvalidNameException: WFNAM00007: Invalid URL scheme name "http-remoting"
We have also tried:
http-remoting://127.0.0.1:8080
remoting+http://127.0.0.1:8080
But we get the same exception.
Here's the main part of my code:
private static final String DEFAULT_MESSAGE = "Hello, World!";
private static final String DEFAULT_CONNECTION_FACTORY = "jms/RemoteConnectionFactory";
private static final String DEFAULT_DESTINATION = "jms/queue/myqueue";
private static final String DEFAULT_MESSAGE_COUNT = "1";
private static final String DEFAULT_USERNAME = "john";
private static final String DEFAULT_PASSWORD = "doe";
private static final String INITIAL_CONTEXT_FACTORY = "org.wildfly.naming.client.WildFlyInitialContextFactory";
private static final String PROVIDER_URL = "http-remoting://127.0.0.1:8080";
Context namingContext = null;
String userName = System.getProperty("username", DEFAULT_USERNAME);
String password = System.getProperty("password", DEFAULT_PASSWORD);
// Set up the namingContext for the JNDI lookup
final Properties env = new Properties();
env.put(Context.INITIAL_CONTEXT_FACTORY, INITIAL_CONTEXT_FACTORY);
env.put(Context.PROVIDER_URL, System.getProperty(Context.PROVIDER_URL, PROVIDER_URL));
env.put(Context.SECURITY_PRINCIPAL, userName);
env.put(Context.SECURITY_CREDENTIALS, password);
namingContext = new InitialContext(env);
// Perform the JNDI lookups
String connectionFactoryString = System.getProperty("connection.factory", DEFAULT_CONNECTION_FACTORY);
log.info("Attempting to acquire connection factory \"" + connectionFactoryString + "\"");
ConnectionFactory connectionFactory = (ConnectionFactory) namingContext.lookup(connectionFactoryString);
log.info("Found connection factory \"" + connectionFactoryString + "\" in JNDI");
The exception occurs at this line:
ConnectionFactory connectionFactory = (ConnectionFactory) namingContext.lookup(connectionFactoryString);
These are the dependencies in pom.xml:
<dependency>
<groupId>org.jboss.eap</groupId>
<artifactId>wildfly-jms-client-bom</artifactId>
<version>7.3.4.GA</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.jboss.eap</groupId>
<artifactId>wildfly-ejb-client-bom</artifactId>
<version>7.3.4.GA</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.jboss.spec.javax.jms</groupId>
<artifactId>jboss-jms-api_2.0_spec</artifactId>
<version>1.0.0.Final-redhat-1</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.8.0</version>
</dependency>
<dependency>
<groupId>org.jboss</groupId>
<artifactId>jboss-ejb-client</artifactId>
<version>4.0.37.Final</version>
</dependency>
<dependency>
<groupId>org.wildfly.common</groupId>
<artifactId>wildfly-common</artifactId>
<version>1.5.4.Final</version>
</dependency>
<dependency>
<groupId>org.jboss.remotingjmx</groupId>
<artifactId>remoting-jmx</artifactId>
<version>3.0.4.Final</version>
</dependency>

It looks to me like your classpath has overlapping classes on it. I see the same thing in your pom.xml. This will cause the wrong classes to be loaded at runtime.
For example, if you look at the pom.xml of the HelloWorld-JMS project you'll see that it only uses the wildfly-jms-client-bom. In fact, the whole point of such a "bom" (i.e. bill of materials) is to incorporate all the required dependencies into a single dependency. Therefore, I recommend you just use this in your pom.xml:
<dependency>
<groupId>org.jboss.eap</groupId>
<artifactId>wildfly-jms-client-bom</artifactId>
<version>7.3.4.GA</version>
<type>pom</type>
</dependency>
Likewise, on your application's classpath you should only have the dependencies of wildfly-jms-client-bom on your classpath (or aggregated equivalents).

Why Wildfly does not find the postgresql driver

I am developping a multi-tier software using java. The middle tier is a java ejb accessing the postgresql database. But when I run the client java application, I have the following error messages:
INFO: EJBCLIENT000069: Using legacy jboss-ejb-client.properties security configuration
Exception in thread "main" javax.ejb.EJBException: WFLYEJB0442: Unexpected Error
....
Caused by: java.lang.NoClassDefFoundError: org/postgresql/Driver
...
Caused by: java.lang.ClassNotFoundException: org.postgresql.Driver
The content of the module.xml file is:
<?xml version="1.0" encoding="utf-8" ?>
<module xmlns="urn:jboss:module:1.3" name="org.postgresql">
<resources>
<!--the name of your driver -->
<resource-root path="postgresql-42.2.6.jar"/>
</resources>
<dependencies>
<module name="javax.api"/>
<module name="javax.transaction.api"/>
</dependencies>
</module>
The following lines have been added to the standalone.xml file:
<driver name="postgresql" module="org.postgresql">
<driver-class>org.postgresql.Driver</driver-class>
<xa-datasource-class>org.postgresql.xa.PGXADataSource</xa-datasource-
class>
</driver>
The driver and the module.xml are in folder \modules\org\postgresql\main. I have successfully tested my code by moving it to a single-tier java application. I am using Eclipse jee latest verion, wildfly 16, postgresql 11. the driver is postgresql-42.2.6.jar
I have already spent several days battling with the problem, but no success. Help most welcome.
package loginPackage;
import java.sql.Connection;
import java.sql.DriverManager;
import org.postgresql.Driver;
import java.sql.SQLException;
public class LoginDao {
static String errorMessage;
static String connectionResult;
public static String getConnectionResult() {
return connectionResult;
}
public static void setConnectionResult(String connectResult) {
connectionResult = connectResult;
}
public String getErrorMessage() {
return errorMessage;
}
public static void setErrorMessage(String errorMsg) {
errorMessage = errorMsg;
}
public static void LoginCheck(String userCode, String userPswd) {
setConnectionResult(userConnect(userCode, userPswd));
}
public static String userConnect(String userCode, String userPaswd) {
try {
//Connection conn = null;
setConnectionResult("OK");
setErrorMessage("OK");
Driver driver = new org.postgresql.Driver();
DriverManager.registerDriver(driver);
Connection conn = DriverManager.getConnection("jdbc:postgresql://localhost:5432/TestDb", userCode, userPaswd);
System.out.println("Connected to PostgreSQL database!");
return "SUCCESS";
}
catch (Exception e) {
System.out.println("Failed to create JDBC db connection " + e.toString() + e.getMessage());
setErrorMessage(userCode + ", " + userPaswd + ", " + e.toString() + ", " + e.getMessage() + ", " + e.getStackTrace());
return "FAILURE" ;
}
}
}

JBoss EJB Client handler missing argument

I am trying to set a new InitialContext in the following manner (which is pretty standard I believe):
private static InitialContext getInitialContext() throws NamingException {
InitialContext context = null;
try {
Properties properties = new Properties();
properties.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
properties.put(Context.INITIAL_CONTEXT_FACTORY, "org.jboss.naming.remote.client.InitialContextFactory");
properties.put(Context.PROVIDER_URL, "remote://localhost:4447");
properties.put(Context.SECURITY_PRINCIPAL, "username");
properties.put(Context.SECURITY_CREDENTIALS, "password");
context = new InitialContext(properties);
System.out.println("\n\tGot initial Context: " + context);
}
catch (Exception e) {
e.printStackTrace();
}
return context;
}
public static void sendMessage(RoboticsParameters object_msg) throws Exception {
InitialContext context = getInitialContext();
// other code
}
The code "fails" at the line where the new InitialContext is created using the properties and i get a java.lang.NullPointerException. I suspect I am missing an argument. Here is the stack trace:
WARN: EJB client integration will not be available due to a problem setting up the EJB client handler java.lang.NullPointerException
at org.jboss.naming.remote.client.InitialContextFactory.<clinit>(InitialContextFactory.java:118)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at com.sun.naming.internal.VersionHelper12.loadClass(VersionHelper12.java:72)
at com.sun.naming.internal.VersionHelper12.loadClass(VersionHelper12.java:61)
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:672)
at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:313)
at javax.naming.InitialContext.init(InitialContext.java:244)
at javax.naming.InitialContext.<init>(InitialContext.java:216)
Any suggestions?
I am running JBoss EAP 6.4 and using EJB 3. I have jboss-client.jar in the class path.

I checked the source code for:
jboss-remote-naming/src/main/java/org/jboss/naming/remote/client/InitialContextFactory.java
and found where the log message was coming from:
public class InitialContextFactory implements javax.naming.spi.InitialContextFactory {
// code
private static final String REMOTE_NAMING_EJB_CLIENT_HANDLER_CLASS_NAME = "org.jboss.naming.remote.client.ejb.RemoteNamingStoreEJBClientHandler";
// code
try {
klass = classLoader.loadClass(REMOTE_NAMING_EJB_CLIENT_HANDLER_CLASS_NAME);
method = klass.getMethod("setupEJBClientContext", new Class<?>[] {Properties.class, List.class});
} catch (Throwable t) {
logger.warn("EJB client integration will not be available due to a problem setting up the EJB client handler", t);
}
// other code
}
The class org.jboss.naming.remote.client.ejb.RemoteNamingStoreEJBClientHandler was in the jar that I added to the class path but for some reason there were problems loading the class.
Then I stumbled upon this small README-EJB-JMS.txt file in the [jboss_home]/bin/client folder which states the following:
"Maven users should not use this jar, but should use the following BOM dependencies instead
<dependencies>
<dependency>
<groupId>org.jboss.as</groupId>
<artifactId>jboss-as-ejb-client-bom</artifactId>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.jboss.as</groupId>
<artifactId>jboss-as-jms-client-bom</artifactId>
<type>pom</type>
</dependency>
</dependencies>
This is because using maven with a shaded jar has a very high chance of causing class version conflicts, which is why
we do not publish this jar to the maven repository."
So, I added the maven dependency instead of having the jar in my class path and VOILA! It works!

List all deployments from Jboss using either JMX or JNDI

Is there a way to get a list of all deployments on a Jboss 6.0
implemented in Java either using JMX (ServerMBean) or JNDI?

On Wildfly 9.0.1.Final the code looks like this:
String host = "localhost";
int port = 9990;
String urlString = System.getProperty("jmx.service.url","service:jmx:http-remoting-jmx://" + host + ":" + port);
JMXServiceURL serviceURL = new JMXServiceURL(urlString);
JMXConnector jmxConnector = JMXConnectorFactory.connect(serviceURL, null);
MBeanServerConnection connection = jmxConnector.getMBeanServerConnection();
ObjectName name = new ObjectName("jboss.modules:type=ModuleLoader,name=*");
Set<ObjectInstance> objectInstances = connection.queryMBeans(name, null);
for (ObjectInstance objectInstance : objectInstances) {
if (objectInstance.getObjectName().getCanonicalName().contains("ServiceModuleLoader")) {
System.out.println("invoking method on " + objectInstance.getObjectName());
Object dumpAllModuleInformation = connection.invoke(objectInstance.getObjectName(), "dumpAllModuleInformation", new Object[]{}, new String[]{});
System.out.println(dumpAllModuleInformation);
}
}
jmxConnector.close();
Maybe you can adapt this to JBoss 6. On Wildfly 9.0.1.Finale this outputs:
Module deployment.stackoverflow-jboss-1.0-SNAPSHOT.war:main
Class loader: ModuleClassLoader for Module "deployment.stackoverflow-jboss-1.0-SNAPSHOT.war:main" from Service Module Loader
Resource Loaders:
Loader Type: org.jboss.as.server.deployment.module.VFSResourceLoader
Paths:
META-INF
META-INF/maven
META-INF/maven/stackoverflow-jboss