HBaseにJavaからアクセス

• ライブラリー&初期設定&基本サンプル
  • HBase0.20 [2010-02-20]
  • HBase0.89 [2010-07-11]
• コーディング
  • HTable [2010-07-11]
  • データ操作 [/2010-07-15]
  • テーブル操作 [2010-02-27]
  • トランザクション [/2010-05-17]
  • 一意制約付き登録 [2010-07-13]

• HBase API（英語）

• クラス
  • HTablePool [2010-07-08]
  • Result [2010-07-11]
  • KeyValue [2010-07-11]
  • Scan [2010-07-25]
  • Filter [/2010-08-15]
  • Bytes

• Hadoop関連クラス [/2012-04-28]

• HadoopからHBaseを操作するサンプル

• get
  • value [/2010-07-11]
  • map
  • list [/2010-02-28]
• exists

• put
  • lockRow [/2010-07-15]
  • checkAndPut
    • checkAndPutの応用例
• incrementColumnValue [2010-07-12]
• delete [/2010-03-06]
  • checkAndDelete [2010-07-11]
• flushCommits [2010-02-24]

• scan
  • filter

Result r = table.get(new Get(Bytes.toBytes("KEY00001")));
byte[] v = r.getValue(Bytes.toBytes("ColumnFamilyA",
                       HConstants.EMPTY_BYTE_ARRAY));

Result r = table.get(new Get(Bytes.toBytes("KEY00001")));
byte[] v = r.getValue(Bytes.toBytes("ColumnFamilyA",
                       Bytes.toBytes("Column1")));

byte[] v = r.getValue(Bytes.toBytes("ColumnFamilyA:Column1")));

Result r = table.get(new Get(Bytes.toBytes("KEY00001")));
NavigableMap<byte[], byte[]> map = r.getFamilyMap(Bytes.toBytes("ColumnFamilyA"));
for (Entry<byte[], byte[]> entry : map.entrySet()) {
	String key = Bytes.toString(entry.getKey());
	String val = Bytes.toString(entry.getValue());
〜
}

Result r = table.get(new Get(Bytes.toBytes("KEY00001")));
NavigableMap<byte[], NavigableMap<byte[], byte[]>> map = r.getNoVersionMap();
for (Entry<byte[], NavigableMap<byte[], byte[]>> entry : map.entrySet()) {
	String key = Bytes.toString(entry.getKey());
	NavigableMap<byte[], byte[]> m = entry.getValue();
〜
}

Result r = table.get(new Get(Bytes.toBytes("KEY00001")));
KeyValue[] sorted = r.sorted();
for (KeyValue kv : sorted) {
	String k = Bytes.toString(kv.getRow());
	String f = Bytes.toString(kv.getFamily());
	String c = Bytes.toString(kv.getQualifier());
	String v = Bytes.toString(kv.getValue());
	System.out.println(k + "/" + f + ":" + c + "=" + v);
}

Result r = table.get(new Get(Bytes.toBytes("KEY00001")));
List<KeyValue> list = r.list();
for (KeyValue kv : list) {
	String k = Bytes.toString(kv.getRow());
	String f = Bytes.toString(kv.getFamily());
	String c = Bytes.toString(kv.getQualifier());
	String v = Bytes.toString(kv.getValue());
	System.out.println(k + "/" + f + ":" + c + "=" + v);
}

KeyValue[] raw = r.raw();

int size = r.size();

Get g = new Get(Bytes.toBytes("KEY00001"));
boolean b = table.exists(g);

Put p = new Put(Bytes.toBytes("KEY00001"));
p.add(Bytes.toBytes("ColumnFamilyA"), Bytes.toBytes("Column1"), 
	Bytes.toBytes("data"));
table.put(p);

Put p = new Put(Bytes.toBytes("KEY00001"));
p.add(Bytes.toBytes("ColumnFamilyA"), HConstants.EMPTY_BYTE_ARRAY, 
	Bytes.toBytes("data"));
table.put(p);

Put p = new Put(Bytes.toBytes("KEY00001"));
KeyValue kv = new KeyValue(p.getRow(), 
	Bytes.toBytes("ColumnFamilyA"), Bytes.toBytes("Column1"),
	Bytes.toBytes("data"));
p.add(kv);
table.put(p);

RowLock lock = table.lockRow(Bytes.toBytes("KEY00001"));
try {
	Put p = new Put(lock.getRow(), lock);
	p.add(Bytes.toBytes("ColumnFamilyA"), Bytes.toBytes("Column1"),
		Bytes.toBytes("data"));
	table.put(p);
} finally {
	table.unlockRow(lock);
}

Get g = new Get(Bytes.toBytes("KEY00001"));
Result r = table.get(g);

byte[] f = Bytes.toBytes("ColumnFamilyA");
byte[] q = Bytes.toBytes("Column1");
byte[] v = r.getValue(f, q);

Put p = new Put(g.getRow());
p.add(f, q, Bytes.toBytes("data"));

boolean b = table.checkAndPut(g.getRow(), f, q, v, p);

Get g = new Get(Bytes.toBytes("KEY00001"));
Result r = table.get(g);
byte[] gf = Bytes.toBytes("ColumnFamilyA");
byte[] gq = Bytes.toBytes("Column1");
byte[] gv = r.getValue(gf, gq);

Put p = new Put(Bytes.toBytes("KEY00002"));
byte[] pf = Bytes.toBytes("ColumnFamilyB");
byte[] pq = Bytes.toBytes("Column2");
byte[] pv = Bytes.toBytes("data");
p.add(pf, pq, pv);

boolean b = table.checkAndPut(g.getRow(), gf, gq, gv, p);

byte[] row       = Bytes.toBytes("cnt1");
byte[] family    = Bytes.toBytes("data");
byte[] qualifier = Bytes.toBytes("cnt");
long    amount   = 1; //加算する値
boolean writeWAL = true;

long ret = table.incrementColumnValue(row, family, qualifier, amount, writeWAL);

Delete d = new Delete(Bytes.toBytes("KEY00001"));
d.deleteColumn(Bytes.toBytes("ColumnFamilyA"), Bytes.toBytes("Column1"));
//d.deleteColumn(Bytes.toBytes("ColumnFamilyA:Column1"));
table.delete(d);

Delete d = new Delete(Bytes.toBytes("KEY00001"));
d.deleteColumns(Bytes.toBytes("ColumnFamilyA"), Bytes.toBytes("Column1"));
table.delete(d);

Delete d = new Delete(Bytes.toBytes("KEY00001"));
d.deleteFamily(Bytes.toBytes("ColumnFamilyA"));
table.delete(d);

Delete d = new Delete(Bytes.toBytes("KEY00001"));
table.delete(d);

Get g = new Get(Bytes.toBytes("KEY00001"));
Result r = table.get(g);

byte[] f = Bytes.toBytes("ColumnFamilyA");
byte[] q = Bytes.toBytes("Column1");
byte[] v = r.getValue(f, q);

Delete d = new Delete(g.getRow());
d.deleteColumns(f, q);
boolean b = table.checkAndDelete(g.getRow(), f, q, v, d);

table.setAutoFlush(false);

table.flushCommits();

ResultScanner rs = table.getScanner(Bytes.toBytes("ColumnFamilyA"));
try {
	for (Result r : rs) {
		System.out.println(Bytes.toString(r.getRow()));
	}
} finally {
	rs.close();
}

	for (Iterator<Result> i = rs.iterator(); i.hasNext();) {
		Result r = i.next();
		System.out.println(Bytes.toString(r.getRow()));
	}

	Result[] ra = rs.next(100);

ResultScanner rs = table.getScanner(
	Bytes.toBytes("ColumnFamilyA"),
	Bytes.toBytes("Column1")
);

byte[] start = Bytes.toBytes("KEY00001");
byte[] stop  = Bytes.toBytes("KEY00004");
Scan scan = new Scan(start, stop);
ResultScanner s = table.getScanner(scan);

byte[] start = Bytes.toBytes("");

Filter filter = new ValueFilter(
	ValueFilter.CompareOp.EQUAL,
	new BinaryComparator(Bytes.toBytes("k1_cfA_c1"))
);

Scan scan = new Scan(start, filter);
ResultScanner s = table.getScanner(scan);
try {
	for (Result r : s) {
		List<KeyValue> list = r.list();
		for (KeyValue kv : list) {
			System.out.println(kv + "/value="
				+ Bytes.toString(kv.getValue()));
		}
	}
} finally {
	s.close();
}