i got this exception while i run hbase client...

Question

import java.io.IOException;

import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.client.Get; import org.apache.hadoop.hbase.client.HTable; import org.apache.hadoop.hbase.client.Put; import org.apache.hadoop.hbase.client.Result; import org.apache.hadoop.hbase.client.ResultScanner; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.util.Bytes;

public class HBaseExample { public static void main(String[] args) throws IOException {

HBaseConfiguration config = new HBaseConfiguration();

HTable table = new HTable(config, "myLittleHBaseTable");



Put p = new Put(Bytes.toBytes("myLittleRow"));

p.add(Bytes.toBytes("myLittleFamily"), Bytes.toBytes("someQualifier"),
  Bytes.toBytes("Some Value"));


table.put(p);

Get g = new Get(Bytes.toBytes("myLittleRow"));
Result r = table.get(g);
byte [] value = r.getValue(Bytes.toBytes("myLittleFamily"),
  Bytes.toBytes("someQualifier"));

String valueStr = Bytes.toString(value);
System.out.println("GET: " + valueStr);

Scan s = new Scan();
s.addColumn(Bytes.toBytes("myLittleFamily"), Bytes.toBytes("someQualifier"));
ResultScanner scanner = table.getScanner(s);
try {

ult instances. // Now, for the actual iteration. One way is to use a while loop like so: for (Result rr = scanner.next(); rr != null; rr = scanner.next()) { // print out the row we found and the columns we were looking for System.out.println("Found row: " + rr); }

} finally {

clause scanner.close(); } } }

Caused by: java.lang.ClassNotFoundException: HBaseExample at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) Could not find the main class: HBaseExample. Program will exit.

Answer 1

How are you running this test? You need to make sure that both the Hadoop and the HBase jars are in your classpath when running it. I recommend running it within the context of Hadoop, for example

/usr/local/hadoop/bin/hadoop jar YourJar.jar

Chances are your problem is something classpath-related.