其實可以通過 hbase shell 在配置文件裏面增加 coprocessor 的選項,但是我個人覺得不太方便
代碼方面可以對 單獨的表進行控制,覺得更爲實用和方便一些, 下面貼上了本人的代碼,增加了是否註冊協處理器的判斷,以前的代碼 如果查詢兩次,會因爲註冊了協處理器導致再次註冊報錯,而且表會進入 disable狀態, 現在的代碼不會出現問題,算是小小的改進,
package com.ruif.hbase.service;
import java.io.IOException;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.TreeSet;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.HTableInterface;
import org.apache.hadoop.hbase.client.HTablePool;
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.client.coprocessor.AggregationClient;
import org.apache.hadoop.hbase.client.coprocessor.LongColumnInterpreter;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.filter.FilterList;
import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter;
import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
import org.apache.hadoop.hbase.io.compress.Compression.Algorithm;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Test;
import com.opensymphony.module.sitemesh.filter.PageFilter;
import com.ruif.utils.TimeUtil;
public class HbaseTest2 {
public static void main(String[] args) throws Throwable {
Configuration conf = HBaseConfiguration.create();
System.setProperty("hadoop.home.dir", "E:/hadoop");
myHbaseConf(conf);
/**
* 通過協處理器獲得行數,不修改 hbase.site
*/
rowCount2("a02", conf);
}
private static void rowCount2(String tableName, Configuration conf) throws IllegalArgumentException, Throwable {
String coprocessorClassName = "org.apache.hadoop.hbase.coprocessor.AggregateImplementation";
HBaseAdmin admin = new HBaseAdmin(conf);
HTableDescriptor htd = admin.getTableDescriptor(Bytes.toBytes(tableName));
boolean flag = htd.hasCoprocessor(coprocessorClassName);// 有就是true 沒有就是 false
if (!flag) {
admin.disableTable(tableName);
htd.addCoprocessor(coprocessorClassName);
admin.modifyTable(Bytes.toBytes(tableName), htd);
admin.enableTable(tableName);
}
AggregationClient ac = new AggregationClient(conf);
Scan scan = new Scan();
scan.addFamily(Bytes.toBytes("info"));
long rowCount = 0;
rowCount = ac.rowCount(TableName.valueOf(Bytes.toBytes(tableName)), new LongColumnInterpreter(), scan);
System.out.println(rowCount);
}
private static void myHbaseConf(Configuration conf) {
conf.set("hbase.zookeeper.quorum", "hadoop01:2181,hadoop02:2181,hadoop03:2181");
}
}
有協處理器和沒有的表描述是有差別的