How can i read from cassandra using flink in java or python.I didn't find a good documentation on this subject.And i want to connect this code to my website.How is that.
I have this code but it runs out an exception
java.lang.NoClassDefFoundError: org/apache/flink/api/common/typeinfo/TypeHint
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
at java.lang.Class.getMethod0(Class.java:3018)
at java.lang.Class.getMethod(Class.java:1784)
at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: org.apache.flink.api.common.typeinfo.TypeHint
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
import com.datastax.driver.core.Cluster;
import org.apache.flink.api.common.typeinfo.TypeHint;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple5;
import org.apache.flink.api.java.typeutils.TupleTypeInfo;
import org.apache.flink.batch.connectors.cassandra.CassandraInputFormat;
import org.apache.flink.streaming.connectors.cassandra.ClusterBuilder;
public class main {
public static void main(String[] args) {
final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
ClusterBuilder clusterBuilder = new ClusterBuilder() {
@Override
public Cluster buildCluster(Cluster.Builder builder) {
return builder.addContactPoint("127.0.0.1").withPort(9042).build();
}
};
DataSet<Tuple5<String,String,String,Integer,String>> inputRecords = env
.createInput
(new CassandraInputFormat<Tuple5<String,String,String,Integer,String>>("Select profilealternative from profiles.profile LIMIT 1 ;",clusterBuilder)
,TupleTypeInfo.of(new TypeHint<Tuple5<String,String,String,Integer,String>>() {}));
}
}
The class you are missing in classpath comes from flink-dist.jar file ( name also depends on version for e.g, flink-dist_2.12-1.9.0.jar). Please check the file is in your classpath while running the program. Also you might require other jars typically present in apache-flink distribution lib directory. You may also create a fat jar containing all the dependencies and then run.