com.kylinolap.storage.hbase.PingHBaseCLI.java Source code

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Here is the source code for com.kylinolap.storage.hbase.PingHBaseCLI.java

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/*
 * Copyright 2013-2014 eBay Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.kylinolap.storage.hbase;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.client.HConnection;
import org.apache.hadoop.hbase.client.HConnectionManager;
import org.apache.hadoop.hbase.client.HTableInterface;
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.security.User;
import org.apache.hadoop.hbase.security.token.TokenUtil;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.security.UserGroupInformation;

import com.kylinolap.common.util.HadoopUtil;

/**
 * @author yangli9
 * 
 */
public class PingHBaseCLI {

    public static void main(String[] args) throws IOException {
        String metadataUrl = args[0];
        String hbaseTable = args[1];

        System.out.println("Hello friend.");

        Configuration hconf = HadoopUtil.newHBaseConfiguration(metadataUrl);
        if (User.isHBaseSecurityEnabled(hconf)) {
            try {
                System.out.println("--------------Getting kerberos credential for user "
                        + UserGroupInformation.getCurrentUser().getUserName());
                TokenUtil.obtainAndCacheToken(hconf, UserGroupInformation.getCurrentUser());
            } catch (InterruptedException e) {
                System.out.println("--------------Error while getting kerberos credential for user "
                        + UserGroupInformation.getCurrentUser().getUserName());
            }
        }

        Scan scan = new Scan();
        int limit = 20;

        HConnection conn = null;
        HTableInterface table = null;
        ResultScanner scanner = null;
        try {
            conn = HConnectionManager.createConnection(hconf);
            table = conn.getTable(hbaseTable);
            scanner = table.getScanner(scan);
            int count = 0;
            for (Result r : scanner) {
                byte[] rowkey = r.getRow();
                System.out.println(Bytes.toStringBinary(rowkey));
                count++;
                if (count == limit)
                    break;
            }
        } finally {
            if (scanner != null) {
                scanner.close();
            }
            if (table != null) {
                table.close();
            }
            if (conn != null) {
                conn.close();
            }
        }

    }
}