/**
* 删除指定表名
*
* @param rowKey
*/
public void deleteTable(byte[] rowKey) {
Connection conn = null;
HBaseAdmin admin = null;
try {
conn = ConnectionFactory.createConnection(conf);
admin = (HBaseAdmin) conn.getAdmin();
// 在删除一张表前，要使其失效
admin.disableTable(rowKey);
admin.deleteTable(rowKey);
admin.enableTable(rowKey);
} catch (Exception e) {
logger.error("HBaseAdmin deleteTable exception, errMsg:{}", e.getMessage());
} finally {
try {
if (null != admin) {
admin.close();
}
} catch (IOException e) {
logger.error("HBaseAdmin close exception, errMsg:{}", e.getMessage());
}
try {
if (null != conn) {
conn.close();
}
} catch (Exception e) {
logger.error("Connection close exception, errMsg:{}", e.getMessage());
}
}
}
public static synchronized void dropTableIfExists() throws Exception {
HBaseAdmin admin = HBaseUtils.getHBaseAdmin();
if (admin.tableExists(TABLE_NAME)) {
admin.disableTable(TABLE_NAME);
admin.deleteTable(TABLE_NAME);
}
}
/**
* Drops table in HBase when it exists.
*
* @param conf
* @throws IOException
*/
public void dropTable() throws IOException {
if (exists()) {
HBaseAdmin admin = new HBaseAdmin(getConfiguration());
admin.disableTable(getStringName());
admin.deleteTable(getStringName());
}
}
/** alter用于修改表明。需要新旧两个表明作为参数。 */
@Override
public Builder alter() {
if (type == 2) {
// 修改表名。snapshot
final String snapshotName = "snapShotName";
try {
if (!hBaseAdmin.tableExists(tableName)
|| tableName == null
|| tableName.trim().equals("")) {
Log.error("=== LiMingji Debug Info === TableName is invalid");
return this;
}
if (newTableName == null || newTableName.trim().equals("")) {
Log.error("=== LiMingji error Info === newTableName is invalid");
return this;
}
if (!hBaseAdmin.isTableDisabled(tableName)) hBaseAdmin.disableTable(tableName);
// 删除可能存在的snapShotName
try {
hBaseAdmin.deleteSnapshot(snapshotName);
} catch (IOException e) {
// Do nothing.
}
hBaseAdmin.snapshot(snapshotName, tableName);
hBaseAdmin.cloneSnapshot(snapshotName, newTableName);
hBaseAdmin.deleteSnapshot(snapshotName);
hBaseAdmin.deleteTable(tableName);
} catch (InterruptedException e) {
Log.info("=== LiMingji error Info === alter@DTL interrupt");
} catch (IOException e) {
Log.error("=== LiMingji error Info === alter@DTL IOException");
}
}
return this;
}
/**
* @param table
* @return
*/
public boolean createTable(JSONObject table) {
try {
String table_name = "";
if (!table.has(XHBaseConstant.TABLE_DESC_NAME)) return false;
table_name = (String) table.get(XHBaseConstant.TABLE_DESC_NAME);
if (table_name.isEmpty()) return false;
if (admin.tableExists(table_name)) {
admin.disableTable(table_name);
admin.deleteTable(table_name);
}
HTableDescriptor td = this.createTableDescription(table);
this.admin.createTable(td);
return true;
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
/*
* 删除表
*
* @tableName 表名
*/
public static void deleteTable(String tableName) throws IOException {
@SuppressWarnings("resource")
HBaseAdmin admin = new HBaseAdmin(conf);
admin.disableTable(tableName);
admin.deleteTable(tableName);
System.out.println(tableName + "is deleted!");
}
protected void dropTable(String tableName) throws IOException {
if (admin.tableExists(tableName)) {
try {
admin.disableTable(tableName);
} catch (TableNotEnabledException ignored) {
}
admin.deleteTable(tableName);
}
}
/**
* delete table in preparation for next test
*
* @param tablename
* @throws IOException
*/
void deleteTable(HBaseAdmin admin, String tablename) throws IOException {
try {
byte[] tbytes = Bytes.toBytes(tablename);
admin.disableTable(tbytes);
admin.deleteTable(tbytes);
} catch (Exception e) {
// Do nothing.
}
}
/**
* 删除表
*
* @param tableName 表名
*/
public void deleteTable(String tableName) {
try {
HBaseAdmin admin = new HBaseAdmin(conf);
admin.disableTable(tableName);
admin.deleteTable(tableName);
} catch (Exception e) {
logger.error("deleteTable failed", e);
}
}
public static void main(String... args)
throws IOException, ClassNotFoundException, InterruptedException {
UserGroupInformation.loginUserFromKeytab("web_dp", "web_dp.keytab");
Configuration conf = HBaseConfiguration.create();
HBaseAdmin admin = new HBaseAdmin(conf);
if (admin.tableExists(QueryDataListener.TN_BYTES_DOMAIN)) {
admin.disableTable(QueryDataListener.TN_BYTES_DOMAIN);
admin.deleteTable(QueryDataListener.TN_BYTES_DOMAIN);
}
if (admin.tableExists(QueryDataListener.TN_BYTES_URL)) {
admin.disableTable(QueryDataListener.TN_BYTES_URL);
admin.deleteTable(QueryDataListener.TN_BYTES_URL);
}
if (admin.tableExists(QueryDataListener.TN_BYTES_QUERY)) {
admin.disableTable(QueryDataListener.TN_BYTES_QUERY);
admin.deleteTable(QueryDataListener.TN_BYTES_QUERY);
}
}
private void deleteTable(final TableName tableName) throws Exception {
// NOTE: We need a latch because admin is not sync,
// so the postOp coprocessor method may be called after the admin operation returned.
MasterSyncObserver observer =
(MasterSyncObserver)
UTIL.getHBaseCluster()
.getMaster()
.getMasterCoprocessorHost()
.findCoprocessor(MasterSyncObserver.class.getName());
ADMIN.deleteTable(tableName);
observer.tableDeletionLatch.await();
}
@Test
public void testTableExists() throws IOException {
final String name = "testTableExists";
final byte[] nameBytes = Bytes.toBytes(name);
assertFalse(MetaReader.tableExists(ct, name));
UTIL.createTable(nameBytes, HConstants.CATALOG_FAMILY);
assertTrue(MetaReader.tableExists(ct, name));
HBaseAdmin admin = UTIL.getHBaseAdmin();
admin.disableTable(name);
admin.deleteTable(name);
assertFalse(MetaReader.tableExists(ct, name));
assertTrue(MetaReader.tableExists(ct, Bytes.toString(HConstants.META_TABLE_NAME)));
assertTrue(MetaReader.tableExists(ct, Bytes.toString(HConstants.ROOT_TABLE_NAME)));
}
private static void deleteTables() {
if (admin != null) {
for (TableName tableName : createdTables) {
try {
if (admin.tableExists(tableName)) {
admin.disableTable(tableName);
admin.deleteTable(tableName);
}
} catch (IOException e) {
assertNull("Exception found deleting the table", e);
}
}
}
}
@BeforeClass
public static void doBeforeTestSetup() throws Exception {
HBaseAdmin admin = driver.getConnectionQueryServices(getUrl(), TEST_PROPERTIES).getAdmin();
try {
try {
admin.disableTable(HBASE_DYNAMIC_COLUMNS_BYTES);
admin.deleteTable(HBASE_DYNAMIC_COLUMNS_BYTES);
} catch (org.apache.hadoop.hbase.TableNotFoundException e) {
}
ensureTableCreated(getUrl(), HBASE_DYNAMIC_COLUMNS);
initTableValues();
} finally {
admin.close();
}
}
// 创建一张表，通过HBaseAdmin HTableDescriptor来创建
public static void creat(String tablename, String columnFamily) throws Exception {
HBaseAdmin admin = new HBaseAdmin(configuration);
if (admin.tableExists(tablename)) {
try {
admin.disableTable(tablename);
admin.deleteTable(tablename);
} catch (Exception ex) {
ex.printStackTrace();
}
}
HTableDescriptor tableDesc = new HTableDescriptor(tablename.valueOf(tablename));
tableDesc.addFamily(new HColumnDescriptor(columnFamily));
admin.createTable(tableDesc);
admin.close();
System.out.println("create table success!");
}
private static void clearHBase(Configuration conf) throws IOException {
HBaseAdmin admin = new HBaseAdmin(conf);
if (admin.tableExists(table_bytes)) {
try {
admin.disableTable(table_bytes);
} catch (Exception ex) {
}
try {
admin.deleteTable(table_bytes);
} catch (Exception ex) {
}
}
HTableDescriptor tdesc = new HTableDescriptor(table_bytes);
HColumnDescriptor cdesc = new HColumnDescriptor(colfam0_bytes);
tdesc.addFamily(cdesc);
admin.createTable(tdesc);
}
@Before
public void before() throws IOException {
HBaseAdmin admin = new HBaseAdmin(configuration);
boolean exists = admin.tableExists(TABLE_NAME);
if (exists) {
admin.disableTable(TABLE_NAME);
admin.deleteTable(TABLE_NAME);
}
// tworzenie tabeli HBase
HTableDescriptor table = new HTableDescriptor(TABLE_NAME);
table.addFamily(new HColumnDescriptor(FAMILY_NAME));
table.addFamily(new HColumnDescriptor(LoadMovieData.FAMILY_NAME));
table.addFamily(new HColumnDescriptor(LoadMovieRatingData.FAMILY_NAME));
admin.createTable(table);
}
/**
* Uses SchemaTool to register the required schemas and create the required tables.
*
* @param conf The HBaseConfiguration.
* @param schemaManager The schema manager SchemaTool needs to create the schemas.
*/
private void registerSchemas(Configuration conf, SchemaManager schemaManager) {
HBaseAdmin admin;
try {
// Construct an HBaseAdmin object (required by schema tool), and delete it
// if it exists so we start fresh.
admin = new HBaseAdmin(conf);
if (admin.tableExists("cdk_example_user_profiles")) {
admin.disableTable("cdk_example_user_profiles");
admin.deleteTable("cdk_example_user_profiles");
}
} catch (IOException e) {
throw new RuntimeException(e);
}
// Use the SchemaTool to create the schemas that are in the example-models
// directory, and create the table and column families required by those
// schemas.
SchemaTool tool = new SchemaTool(admin, schemaManager);
tool.createOrMigrateSchemaDirectory("classpath:example-models", true);
}
public static void deleteTableTest(String tableStr) {
try {
Configuration conf = HBaseConfiguration.create();
byte[] tableName = Bytes.toBytes(tableStr);
if (conf == null) {
throw new IOException("conf not set.");
} else {
HBaseAdmin admin = new HBaseAdmin(conf);
if (admin.tableExists(tableName)) {
admin.disableTable(tableName); // 关闭一个表
admin.deleteTable(tableName); // 删除一个表
} else {
throw new IOException("no such table.");
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
@BeforeClass
public static void doBeforeTestSetup() throws Exception {
HBaseAdmin admin = driver.getConnectionQueryServices(getUrl(), TEST_PROPERTIES).getAdmin();
try {
try {
admin.disableTable(HBASE_NATIVE_BYTES);
admin.deleteTable(HBASE_NATIVE_BYTES);
} catch (org.apache.hadoop.hbase.TableNotFoundException e) {
}
HTableDescriptor descriptor = new HTableDescriptor(HBASE_NATIVE_BYTES);
HColumnDescriptor columnDescriptor = new HColumnDescriptor(FAMILY_NAME);
columnDescriptor.setKeepDeletedCells(true);
descriptor.addFamily(columnDescriptor);
admin.createTable(descriptor, SPLITS);
initTableValues();
} finally {
admin.close();
}
}
public HTable createTable(String tableName, String[] metrics, int[] max_version)
throws IOException {
System.out.println("create table for " + tableName);
try {
if (admin.tableExists(tableName)) {
System.out.println(admin.listTables());
admin.disableTable(tableName);
admin.deleteTable(tableName);
}
HTableDescriptor td = this.createTableDescription(tableName, metrics, max_version);
System.out.println(tableName + ": <=>table descirption : " + td.toString());
this.admin.createTable(td);
// this.admin.createTable(td, ("0-").getBytes(), ("2-"+Long.MAX_VALUE).getBytes(),80);
} catch (Exception e) {
e.printStackTrace();
// log.info(e.fillInStackTrace());
}
return new HTable(conf, tableName);
}
@AfterClass
public static void tearDownAfterClass() throws Exception {
if (lilyProxy != null) lilyProxy.stop();
TestHomeUtil.cleanupTestHome(tmpDir);
if (lilyProxy.getMode() == LilyProxy.Mode.CONNECT
|| lilyProxy.getMode() == LilyProxy.Mode.HADOOP_CONNECT) {
// We're in connect mode, drop the tables again so that the remainder of the tests
// don't have the overhead of the extra splits
Configuration conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "localhost");
HBaseAdmin hbaseAdmin = new HBaseAdmin(conf);
for (String tableName : TABLE_NAMES) {
if (hbaseAdmin.tableExists(tableName)) {
hbaseAdmin.disableTable(tableName);
hbaseAdmin.deleteTable(tableName);
}
}
HConnectionManager.deleteConnection(hbaseAdmin.getConfiguration(), true);
}
}
/** 删除给定的表。 */
@Override
public Builder delete() {
if (type == 1) {
try {
if (tableName == null || tableName.trim().equals("")) {
Log.info("=== LiMingji Error Info === No tableName");
return this;
}
if (hBaseAdmin.tableExists(tableName)) {
hBaseAdmin.disableTable(tableName);
hBaseAdmin.deleteTable(tableName);
} else {
Log.info("=== LiMingji Debug Info === Table does not exit");
return this;
}
} catch (IOException e) {
Log.info("=== LiMingji Debug Info === deleteTable@DDL IOException");
e.printStackTrace();
}
}
return this;
}
@BeforeClass
public static void setUpBeforeClass() throws Exception {
lilyProxy = new LilyProxy();
//
// Make multiple record table splits
//
if (lilyProxy.getMode() == LilyProxy.Mode.CONNECT
|| lilyProxy.getMode() == LilyProxy.Mode.HADOOP_CONNECT) {
// The tables will likely already exist and not be recreated, hence we won't be able to change
// the number of regions. Therefore, drop them.
Configuration conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "localhost");
HBaseAdmin hbaseAdmin = new HBaseAdmin(conf);
for (String tableName : TABLE_NAMES) {
if (hbaseAdmin.tableExists(tableName)) {
hbaseAdmin.disableTable(tableName);
hbaseAdmin.deleteTable(tableName);
}
}
HConnectionManager.deleteConnection(hbaseAdmin.getConfiguration(), true);
}
// Temp dir where we will create conf dir
tmpDir = TestHomeUtil.createTestHome("lily-tablesplit-test-");
File customConfDir = setupConfDirectory(tmpDir);
String oldCustomConfDir = setProperty("lily.conf.customdir", customConfDir.getAbsolutePath());
String oldRestoreTemplate = setProperty("lily.lilyproxy.restoretemplatedir", "false");
try {
lilyProxy.start();
} finally {
// Make sure the properties won't be used by later-running tests
setProperty("lily.conf.customdir", oldCustomConfDir);
setProperty("lily.lilyproxy.restoretemplatedir", oldRestoreTemplate);
}
}
public static void deleteTable(String keyspace) throws Exception {
Configuration conf = HBaseConfiguration.create();
HBaseAdmin admin = new HBaseAdmin(conf);
admin.deleteTable(keyspace);
}
/**
* Tests overriding compaction handling via coprocessor hooks
*
* @throws Exception
*/
@Test
public void testCompactionOverride() throws Exception {
byte[] compactTable = Bytes.toBytes("TestCompactionOverride");
HBaseAdmin admin = util.getHBaseAdmin();
if (admin.tableExists(compactTable)) {
admin.disableTable(compactTable);
admin.deleteTable(compactTable);
}
HTableDescriptor htd = new HTableDescriptor(TableName.valueOf(compactTable));
htd.addFamily(new HColumnDescriptor(A));
htd.addCoprocessor(EvenOnlyCompactor.class.getName());
admin.createTable(htd);
HTable table = new HTable(util.getConfiguration(), compactTable);
for (long i = 1; i <= 10; i++) {
byte[] iBytes = Bytes.toBytes(i);
Put put = new Put(iBytes);
put.setDurability(Durability.SKIP_WAL);
put.add(A, A, iBytes);
table.put(put);
}
HRegion firstRegion = cluster.getRegions(compactTable).get(0);
Coprocessor cp =
firstRegion.getCoprocessorHost().findCoprocessor(EvenOnlyCompactor.class.getName());
assertNotNull("EvenOnlyCompactor coprocessor should be loaded", cp);
EvenOnlyCompactor compactor = (EvenOnlyCompactor) cp;
// force a compaction
long ts = System.currentTimeMillis();
admin.flush(compactTable);
// wait for flush
for (int i = 0; i < 10; i++) {
if (compactor.lastFlush >= ts) {
break;
}
Thread.sleep(1000);
}
assertTrue("Flush didn't complete", compactor.lastFlush >= ts);
LOG.debug("Flush complete");
ts = compactor.lastFlush;
admin.majorCompact(compactTable);
// wait for compaction
for (int i = 0; i < 30; i++) {
if (compactor.lastCompaction >= ts) {
break;
}
Thread.sleep(1000);
}
LOG.debug("Last compaction was at " + compactor.lastCompaction);
assertTrue("Compaction didn't complete", compactor.lastCompaction >= ts);
// only even rows should remain
ResultScanner scanner = table.getScanner(new Scan());
try {
for (long i = 2; i <= 10; i += 2) {
Result r = scanner.next();
assertNotNull(r);
assertFalse(r.isEmpty());
byte[] iBytes = Bytes.toBytes(i);
assertArrayEquals("Row should be " + i, r.getRow(), iBytes);
assertArrayEquals("Value should be " + i, r.getValue(A, A), iBytes);
}
} finally {
scanner.close();
}
table.close();
}
/**
* Deletes a HBase table.
*
* @param admin HBase admin
* @param tableDescriptor descriptor for the table to delete
* @throws IOException
*/
private static void deleteTable(final HBaseAdmin admin, final HTableDescriptor tableDescriptor)
throws IOException {
LOG.info("deleting table: " + tableDescriptor.getNameAsString());
admin.disableTable(tableDescriptor.getName());
admin.deleteTable(tableDescriptor.getName());
}
@Test
public void testHostRank() throws Exception {
if (System.getProperty("prop.mapred.job.tracker") != null) {
if (LOG.isInfoEnabled())
LOG.info("testHBaseInputOutput: Ignore this test if not local mode.");
return;
}
File jarTest = new File(System.getProperty("prop.jarLocation"));
if (!jarTest.exists()) {
fail(
"Could not find Giraph jar at "
+ "location specified by 'prop.jarLocation'. "
+ "Make sure you built the main Giraph artifact?.");
}
MiniHBaseCluster cluster = null;
MiniZooKeeperCluster zkCluster = null;
FileSystem fs = null;
try {
// using the restart method allows us to avoid having the hbase
// root directory overwritten by /home/$username
zkCluster = testUtil.startMiniZKCluster();
testUtil.restartHBaseCluster(2);
cluster = testUtil.getMiniHBaseCluster();
final byte[] OL_BYTES = Bytes.toBytes("ol");
final byte[] S_BYTES = Bytes.toBytes("s");
final byte[] METADATA_BYTES = Bytes.toBytes("mtdt");
final byte[] HR_BYTES = Bytes.toBytes("_hr_");
final byte[] TAB = Bytes.toBytes(TABLE_NAME);
Configuration conf = cluster.getConfiguration();
HTableDescriptor desc = new HTableDescriptor(TAB);
desc.addFamily(new HColumnDescriptor(OL_BYTES));
desc.addFamily(new HColumnDescriptor(S_BYTES));
desc.addFamily(new HColumnDescriptor(METADATA_BYTES));
HBaseAdmin hbaseAdmin = new HBaseAdmin(conf);
if (hbaseAdmin.isTableAvailable(TABLE_NAME)) {
hbaseAdmin.disableTable(TABLE_NAME);
hbaseAdmin.deleteTable(TABLE_NAME);
}
hbaseAdmin.createTable(desc);
/**
* Enter the initial data (a,b), (b,c), (a,c) a = 1.0 - google b = 1.0 - yahoo c = 1.0 - bing
*/
HTable table = new HTable(conf, TABLE_NAME);
Put p1 = new Put(Bytes.toBytes("com.google.www"));
p1.add(OL_BYTES, Bytes.toBytes("www.yahoo.com"), Bytes.toBytes("ab"));
Put p2 = new Put(Bytes.toBytes("com.google.www"));
p2.add(OL_BYTES, Bytes.toBytes("www.bing.com"), Bytes.toBytes("ac"));
p2.add(OL_BYTES, Bytes.toBytes("www.bing.com"), Bytes.toBytes("invalid1"));
p2.add(OL_BYTES, Bytes.toBytes("www.google.com"), Bytes.toBytes("invalid2"));
Put p3 = new Put(Bytes.toBytes("com.yahoo.www"));
p3.add(OL_BYTES, Bytes.toBytes("www.bing.com"), Bytes.toBytes("bc"));
// p3.add(OL_BYTES, Bytes.toBytes(""), Bytes.toBytes("invalid4"));
Put p4 = new Put(Bytes.toBytes("com.bing.www"));
// TODO: Handle below case. use apache isValid method.
p4.add(OL_BYTES, Bytes.toBytes("http://invalidurl"), Bytes.toBytes("invalid5"));
p4.add(S_BYTES, S_BYTES, Bytes.toBytes(10.0d));
Put p5 = new Put(Bytes.toBytes("dummy"));
p5.add(S_BYTES, S_BYTES, Bytes.toBytes(10.0d));
table.put(p1);
table.put(p2);
table.put(p3);
table.put(p4);
table.put(p5);
// Set Giraph configuration
// now operate over HBase using Vertex I/O formats
conf.set(TableInputFormat.INPUT_TABLE, TABLE_NAME);
conf.set(TableOutputFormat.OUTPUT_TABLE, TABLE_NAME);
// Start the giraph job
GiraphJob giraphJob = new GiraphJob(conf, BspCase.getCallingMethodName());
GiraphConfiguration giraphConf = giraphJob.getConfiguration();
giraphConf.setZooKeeperConfiguration(cluster.getMaster().getZooKeeper().getQuorum());
setupConfiguration(giraphJob);
giraphConf.setComputationClass(LinkRankComputation.class);
giraphConf.setMasterComputeClass(LinkRankVertexMasterCompute.class);
giraphConf.setOutEdgesClass(ByteArrayEdges.class);
giraphConf.setVertexInputFormatClass(Nutch2HostInputFormat.class);
giraphConf.setVertexOutputFormatClass(Nutch2HostOutputFormat.class);
giraphConf.setInt("giraph.linkRank.superstepCount", 10);
giraphConf.setInt("giraph.linkRank.scale", 10);
giraphConf.set("giraph.linkRank.family", "mtdt");
giraphConf.set("giraph.linkRank.qualifier", "_hr_");
giraphConf.setVertexInputFilterClass(HostRankVertexFilter.class);
assertTrue(giraphJob.run(true));
if (LOG.isInfoEnabled()) LOG.info("Giraph job successful. Checking output qualifier.");
/** Check the results * */
Result result;
String key;
byte[] calculatedScoreByte;
HashMap expectedValues = new HashMap<String, Double>();
expectedValues.put("com.google.www", 1.3515060339386287d);
expectedValues.put("com.yahoo.www", 4.144902009567587d);
expectedValues.put("com.bing.www", 9.063893290511482d);
for (Object keyObject : expectedValues.keySet()) {
key = keyObject.toString();
result = table.get(new Get(key.getBytes()));
calculatedScoreByte = result.getValue(METADATA_BYTES, HR_BYTES);
assertNotNull(calculatedScoreByte);
assertTrue(calculatedScoreByte.length > 0);
Assert.assertEquals(
"Scores are not the same",
(Double) expectedValues.get(key),
Bytes.toDouble(calculatedScoreByte),
DELTA);
}
} finally {
if (cluster != null) {
cluster.shutdown();
}
if (zkCluster != null) {
zkCluster.shutdown();
}
// clean test files
if (fs != null) {
fs.delete(hbaseRootdir);
}
}
}
// Does a Put, Get and a Scan against an hbase table.
@Test
public void exampleTest() {
Configuration config = HBaseConfiguration.create();
config.set("hbase.zookeeper.quorum", "mulisch");
HBaseAdmin admin = null;
try {
admin = new HBaseAdmin(config);
} catch (MasterNotRunningException e) {
e.printStackTrace();
} catch (ZooKeeperConnectionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
// You need a configuration object to tell the client where to connect.
// When you create a HBaseConfiguration, it reads in whatever you've set
// into your hbase-site.xml and in hbase-default.xml, as long as these can
// be found on the CLASSPATH
// HBaseConfiguration config = new HBaseConfiguration();
// This instantiates an HTable object that connects you to
// the "myLittleHBaseTable" table.
HTableDescriptor ext = new HTableDescriptor("testtable");
HColumnDescriptor c1 = new HColumnDescriptor("c1");
HColumnDescriptor c2 = new HColumnDescriptor("c2");
ext.addFamily(c1);
ext.addFamily(c2);
if (!admin.tableExists("testtable")) {
admin.createTable(ext);
}
HTable table = new HTable(config, "testtable");
// To add to a row, use Put. A Put constructor takes the name of the row
// you want to insert into as a byte array. In HBase, the Bytes class has
// utility for converting all kinds of java types to byte arrays. In the
// below, we are converting the String "myLittleRow" into a byte array to
// use as a row key for our update. Once you have a Put instance, you can
// adorn it by setting the names of columns you want to update on the row,
// the timestamp to use in your update, etc.If no timestamp, the server
// applies current time to the edits.
Put p = new Put(Bytes.toBytes("row1"));
// To set the value you'd like to update in the row 'myLittleRow', specify
// the column family, column qualifier, and value of the table cell you'd
// like to update. The column family must already exist in your table
// schema. The qualifier can be anything. All must be specified as byte
// arrays as hbase is all about byte arrays. Lets pretend the table
// 'myLittleHBaseTable' was created with a family 'myLittleFamily'.
p.add(Bytes.toBytes("c1"), Bytes.toBytes("someQualifier"), Bytes.toBytes("Some Value"));
p.add(
Bytes.toBytes("c2"),
Bytes.toBytes("someOtherQualifier"),
Bytes.toBytes("Some Other Value"));
// Once you've adorned your Put instance with all the updates you want to
// make, to commit it do the following (The HTable#put method takes the
// Put instance you've been building and pushes the changes you made into
// hbase)
table.put(p);
// Now, to retrieve the data we just wrote. The values that come back are
// Result instances. Generally, a Result is an object that will package up
// the hbase return into the form you find most palatable.
Get g = new Get(Bytes.toBytes("row1"));
Result r = table.get(g);
byte[] value = r.getValue(Bytes.toBytes("c1"), Bytes.toBytes("someQualifier"));
// If we convert the value bytes, we should get back 'Some Value', the
// value we inserted at this location.
String valueStr = Bytes.toString(value);
System.out.println("GET: " + valueStr);
// Sometimes, you won't know the row you're looking for. In this case, you
// use a Scanner. This will give you cursor-like interface to the contents
// of the table. To set up a Scanner, do like you did above making a Put
// and a Get, create a Scan. Adorn it with column names, etc.
Scan s = new Scan();
s.addColumn(Bytes.toBytes("c1"), Bytes.toBytes("someQualifier"));
ResultScanner scanner = table.getScanner(s);
try {
// Scanners return Result 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);
}
// The other approach is to use a foreach loop. Scanners are iterable!
// for (Result rr : scanner) {
// System.out.println("Found row: " + rr);
// }
} finally {
// Make sure you close your scanners when you are done!
// Thats why we have it inside a try/finally clause
scanner.close();
}
} catch (IOException e) {
e.printStackTrace();
fail("failed with IOException");
}
try {
if (admin.tableExists("testtable")) {
admin.disableTable("testtable");
admin.deleteTable("testtable");
}
} catch (IOException e) {
e.printStackTrace();
}
}
public void dropTable(String table) throws IOException {
if (existsTable(table)) {
disableTable(table);
admin.deleteTable(table);
}
}
