{{{
#!html
<div style="text-align: center; color:#151B8D"><big style="font-weight: bold;"><big><big>
ITRI HBase 進階課程 
</big></big></big></div> <div style="text-align: center; color:#7E2217"><big style="font-weight: bold;"><big>
HBase 範例
</big></big></div>
}}}

[wiki:waue/2011/0426_4_3 上一關 < ] 第四關 [wiki:waue/2011/0426_4_5 > 下一關]

 = 範例四： 掃描並印出指定的column-Qualifier 的所有列值 = 

{{{
#!java

package itri;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.util.GenericOptionsParser;

public class ScanTableV1 {

	static void ScanColumn(String tablename, String family, String column) {
		HBaseConfiguration conf = new HBaseConfiguration();

		HTable table;
		try {
			table = new HTable(conf, Bytes.toBytes(tablename));

			ResultScanner scanner = table.getScanner(Bytes.toBytes(family));

			System.out.println("Scan the Table [" + tablename
					+ "]'s Column => " + family + ":" + column);
			int i = 1;
			for (Result rowResult : scanner) {
				byte[] by = rowResult.getValue(Bytes.toBytes(family), Bytes
						.toBytes(column));
				String str = Bytes.toString(by);
				System.out.println("row " + i + " is \"" + str + "\"");
				i++;
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] argv) {
//		String[] argc = {"t1", "f1", "c1"};argv = argc;
		
		String[] args = new GenericOptionsParser(new Configuration(), argv)
				.getRemainingArgs();
		if (args.length < 3) {
			System.out
					.println("ScanTableV1 <TableName> <Family> <Qualifier> ");
			return;
		}
		ScanColumn(args[0], args[1], args[2]);
	}
}
}}}

 * 執行結果

{{{
Scan the Table [ex1Table]'s Column => Detail:c1
row 1 is "my value good"
}}}

{{{
$ bin/hadoop jar ItriMenu.jar PutData "ex1Table" "row222" "Detail" "c1" "my value better"
$ bin/hadoop jar ItriMenu.jar ScanTable "ex1Table" "Detail" "c1"
row 1 is "my value good"
row 2 is "my value better"

}}}


 = 進階： 給 table name 即可掃出全部值 = 

{{{
#!java
package itri;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HTable;
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;
import org.apache.hadoop.util.GenericOptionsParser;

public class ScanTableV2 {

	static void ScanColumn(String tablename) throws IOException {
		HBaseConfiguration conf = new HBaseConfiguration();

		HTable table = new HTable(conf, Bytes.toBytes(tablename));
		Scan s = new Scan();
		ResultScanner scanner = table.getScanner(s);
		try {

			for (Result rr : scanner) {

				byte[] row_b = rr.getRow();
				String row_s = Bytes.toString(row_b);
				System.out.print("row= " +row_s );
				for (KeyValue kv : rr.list()) {

					byte[] family_b = kv.getFamily();
					String family_s = Bytes.toString(family_b);

					byte[] qfy_b = kv.getQualifier();
					String qfy_s = Bytes.toString(qfy_b);

					Get g = new Get(row_b);
					Result rowResult = table.get(g);
					
					String val = Bytes.toString(rowResult.getValue(family_b,
							qfy_b));
					System.out.print(" {"+family_s +":"+qfy_s +" = "+val +"}");
				}
				System.out.println(" ");
			}

		} finally {
			scanner.close();
		}
	}

	public static void main(String[] argv) throws IOException {
//		String[] argc = {"t1"};argv = argc;

		String[] args = new GenericOptionsParser(new Configuration(), argv)
				.getRemainingArgs();
		if (args.length < 1) {
			System.out.println("ScanTableV2 <TableName> ");
			return;
		}
		ScanColumn(args[0]);
	}
}
}}}