标签：des style blog class code c
1. 创建表：（由master完成）
2. 读写删除数据
3. 版本信息
HbaseConfiguration， 表示HBase的配置信息
两种构造函数如下：
public HBaseConfiguration() -----------默认的构造方式会从hbase-default.xml和hbase-site.xml中读取配置，如果classpath中没有这两个文件，需要自己配置
public HBaseConfiguration(final Configuration c)
eg：
static HBaseConfiguration cfg = null; static { Configuration HBASE_CONFIG = new Configuration(); HBASE_CONFIG.set("hbase.zookeeper.quorum", "192.168.1.95"); HBASE_CONFIG.set("hbase.zookeeper.property.clientPort", "2181"); cfg = new HBaseConfiguration(HBASE_CONFIG); }
使用HBaseAdmin对象的createTable方法
eg：
public static void createTable(String tableName) { System.out.println("************start create table**********"); try { HBaseAdmin hBaseAdmin = new HBaseAdmin(cfg); if (hBaseAdmin.tableExists(tableName)) {// 如果存在要创建的表，那么先删除，再创建 hBaseAdmin.disableTable(tableName); hBaseAdmin.deleteTable(tableName); System.out.println(tableName + " is exist"); } HTableDescriptor tableDescriptor = new HTableDescriptor(tableName);// 代表表的schema tableDescriptor.addFamily(new HColumnDescriptor("name")); //增加列簇 tableDescriptor.addFamily(new HColumnDescriptor("age")); tableDescriptor.addFamily(new HColumnDescriptor("gender")); hBaseAdmin.createTable(tableDescriptor); } catch (MasterNotRunningException e) { e.printStackTrace(); } catch (ZooKeeperConnectionException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } System.out.println("*****end create table*************"); }
public static void main(String[] agrs) { try { String tablename = "wishTest"; HBaseTest.createTable(tablename); } catch (Exception e) { e.printStackTrace(); } }
日志信息如下：
************start create table**********
14/05/18 14:14:22 INFO zookeeper.ZooKeeper: Client environment:zookeeper.version=3.4.5-1392090, built on 09/30/2012 17:52 GMT
14/05/18 14:14:22 INFO zookeeper.ZooKeeper: Client environment:host.name=LJ-PC
14/05/18 14:14:22 INFO zookeeper.ZooKeeper: Client environment:java.version=1.6.0_11
14/05/18 14:14:22 INFO zookeeper.ZooKeeper: Client environment:java.vendor=Sun Microsystems Inc.
14/05/18 14:14:22 INFO zookeeper.ZooKeeper: Client environment:java.home=D:\java\jdk1.6.0_11\jre
14/05/18 14:14:22 INFO zookeeper.ZooKeeper: Client environment:java.class.path=....
...
14/05/18 14:14:22 INFO zookeeper.RecoverableZooKeeper: The identifier of this process is 6560@LJ-PC
14/05/18 14:14:22 INFO zookeeper.ClientCnxn: Socket connection established to hadoop/192.168.1.95:2181, initiating session
14/05/18 14:14:22 INFO zookeeper.ClientCnxn: Session establishment complete on server hadoop/192.168.1.95:2181, sessionid = 0x460dd23bda0007, negotiated timeout = 180000
14/05/18 14:14:22 INFO zookeeper.ZooKeeper: Session: 0x460dd23bda0007 closed
14/05/18 14:14:22 INFO zookeeper.ClientCnxn: EventThread shut down
*****end create table*************
在centos中查看是否创建成功：
网页上查看：
HTableDescriptor其他方法如下：
- setMaxFileSize，指定最大的region size
- setMemStoreFlushSize 指定memstore flush到HDFS上的文件大小，默认是64M
- public void addFamily(final HColumnDescriptor family)
HColumnDescriptor 其他方法如下：
- setTimeToLive:指定最大的TTL,单位是ms,过期数据会被自动删除。
- setInMemory:指定是否放在内存中，对小表有用，可用于提高效率。默认关闭
- setBloomFilter:指定是否使用BloomFilter,可提高随机查询效率。默认关闭
- setCompressionType:设定数据压缩类型。默认无压缩。
- setScope(scope):集群的Replication，默认为flase
- setBlocksize(blocksize); block的大小默认是64kb，block小适合随机读，但是可能导Index过大而使内存oom, block大利于顺序读。
- setMaxVersions:指定数据最大保存的版本个数。默认为3。版本数最多为Integer.MAX_VALUE, 但是版本数过多可能导致compact时out of memory。
- setBlockCacheEnabled:是否可以cache, 默认设置为true，将最近读取的数据所在的Block放入内存中，标记为single，若下次读命中则将其标记为multi
使用HTable获取table 注意：HTable不是线程安全的，因此当多线程插入数据的时候推荐使用HTablePool
使用put插入数据，可以单条插入数据和批量插入数据，put方法如下：
public void put(final Put put) throws IOException
public void put(final List<Put> puts) throws IOException
put 常用方法：
- add:增加一个Cell
- setTimeStamp:指定所有cell默认的timestamp,如果一个Cell没有指定timestamp,就会用到这个值。如果没有调用，HBase会将当前时间作为未指定timestamp的cell的timestamp.
- setWriteToWAL: WAL是Write Ahead Log的缩写，指的是HBase在插入操作前是否写Log。默认是打开，关掉会提高性能，但是如果系统出现故障(负责插入的Region Server挂掉)，数据可能会丢失。
下面两个方法会影响插入性能
- setAutoFlash:
AutoFlush指的是在每次调用HBase的Put操作，是否提交到HBase Server。默认是true,每次会提交。如果此时是单条插入，就会有更多的IO,从而降低性能。进行大量Put时，HTable的setAutoFlush最好设置为flase。否则每执行一个Put就需要和RegionServer发送一个请求。如果autoFlush = false，会等到写缓冲填满才会发起请求。显式的发起请求，可以调用flushCommits。HTable的close操作也会发起flushCommits
- setWriteBufferSize:
Write Buffer Size在AutoFlush为false的时候起作用，默认是2MB,也就是当插入数据超过2MB,就会自动提交到Server
eg:
public static void insert(String tableName) { System.out.println("************start insert ************"); HTablePool pool = new HTablePool(cfg, 1000); Put put = new Put("1".getBytes());// 一个PUT代表一行数据,每行一个唯一的ROWKEY，此处rowkey为1 put.add("name".getBytes(), null, "wish".getBytes());// 本行数据的第一列 put.add("age".getBytes(), null, "20".getBytes());// 本行数据的第三列 put.add("gender".getBytes(), null, "female".getBytes());// 本行数据的第三列 try { pool.getTable(tableName).put(put); } catch (IOException e) { e.printStackTrace(); } System.out.println("************end insert************"); }
public static void main(String[] agrs) { try { String tablename = "wishTest"; HBaseTest.insert(tablename); } catch (Exception e) { e.printStackTrace(); } }
日志信息如下：
************start insert ************
14/05/18 15:01:17 WARN hbase.HBaseConfiguration: instantiating HBaseConfiguration() is deprecated. Please use HBaseConfiguration#create() to construct a plain Configuration
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:zookeeper.version=3.4.5-1392090, built on 09/30/2012 17:52 GMT
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:host.name=LJ-PC
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:java.version=1.6.0_11
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:java.vendor=Sun Microsystems Inc.
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:java.home=D:\java\jdk1.6.0_11\jre
.....
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:java.compiler=<NA>
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:os.name=Windows Vista
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:os.arch=x86
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:os.version=6.1
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:user.name=root
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:user.home=C:\Users\LJ
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Client environment:user.dir=D:\java\eclipse4.3-jee-kepler-SR1-win32\workspace\hadoop
14/05/18 15:01:17 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=192.168.1.95:2181 sessionTimeout=180000 watcher=hconnection
14/05/18 15:01:17 INFO zookeeper.RecoverableZooKeeper: The identifier of this process is 1252@LJ-PC
14/05/18 15:01:17 INFO zookeeper.ClientCnxn: Opening socket connection to server hadoop/192.168.1.95:2181. Will not attempt to authenticate using SASL (无法定位登录配置)
14/05/18 15:01:17 INFO zookeeper.ClientCnxn: Socket connection established to hadoop/192.168.1.95:2181, initiating session
14/05/18 15:01:17 INFO zookeeper.ClientCnxn: Session establishment complete on server hadoop/192.168.1.95:2181, sessionid = 0x460dd23bda000b, negotiated timeout = 180000
************end insert************
查看插入结果：
分为单条查询和批量查询，单条查询通过get查询。 通过HTable的getScanner实现批量查询
public Result get(final Get get) //单条查询
public ResultScanner getScanner(final Scan scan) //批量查询
eg：单条查询：
public static void querySingle(String tableName) { HTablePool pool = new HTablePool(cfg, 1000); try { Get get = new Get("1".getBytes());// 根据rowkey查询 Result r = pool.getTable(tableName).get(get); System.out.println("rowkey:" + new String(r.getRow())); for (KeyValue keyValue : r.raw()) { System.out.println("列：" + new String(keyValue.getFamily()) + " 值:" + new String(keyValue.getValue())); } } catch (IOException e) { e.printStackTrace(); } }
public static void main(String[] agrs) { try { String tablename = "wishTest"; HBaseTest.querySingle(tablename); } catch (Exception e) { e.printStackTrace(); } }
查询结果：
rowkey:1
列：age 值:20
列：gender 值:female
列：name 值:wish
eg：批量查询：
public static void queryAll(String tableName) { HTablePool pool = new HTablePool(cfg, 1000); try { ResultScanner rs = pool.getTable(tableName).getScanner(new Scan()); for (Result r : rs) { System.out.println("rowkey:" + new String(r.getRow())); for (KeyValue keyValue : r.raw()) { System.out.println("列：" + new String(keyValue.getFamily()) + " 值:" + new String(keyValue.getValue())); } } } catch (IOException e) { e.printStackTrace(); } }
public static void main(String[] agrs) { try { String tablename = "wishTest"; HBaseTest.queryAll(tablename); } catch (Exception e) { e.printStackTrace(); } }
结果如下：
rowkey:1
列：age 值:20
列：gender 值:female
列：name 值:wish
rowkey:112233bbbcccc
列：age 值:20
列：gender 值:female
列：name 值:wish
rowkey:2
列：age 值:20
列：gender 值:female
列：name 值:rain
使用HTable的delete删除数据：
public void delete(final Delete delete)
eg:
public static void deleteRow(String tablename, String rowkey) { try { HTable table = new HTable(cfg, tablename); List list = new ArrayList(); Delete d1 = new Delete(rowkey.getBytes()); list.add(d1); table.delete(list); System.out.println("删除行成功!"); } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] agrs) { try { String tablename = "wishTest"; System.out.println("****************************删除前数据**********************"); HBaseTest.queryAll(tablename); HBaseTest.deleteRow(tablename,"112233bbbcccc"); System.out.println("****************************删除后数据**********************"); HBaseTest.queryAll(tablename); } catch (Exception e) { e.printStackTrace(); } }
结果如下：
****************************删除前数据**********************
rowkey:1
列：age 值:20
列：gender 值:female
列：name 值:wish
rowkey:112233bbbcccc
列：age 值:20
列：gender 值:female
列：name 值:wish
rowkey:2
列：age 值:20
列：gender 值:female
列：name 值:rain
删除行成功!
****************************删除后数据**********************
rowkey:1
列：age 值:20
列：gender 值:female
列：name 值:wish
rowkey:2
列：age 值:20
列：gender 值:female
列：name 值:rain
和hbase shell中类似，删除表前需要先disable表；分别使用disableTable和deleteTable来删除和禁用表
同创建表一样需要使用HbaseAdmin
eg：
public static void dropTable(String tableName) { try { HBaseAdmin admin = new HBaseAdmin(cfg); admin.disableTable(tableName); admin.deleteTable(tableName); System.out.println("table: "+tableName+"删除成功！"); } catch (MasterNotRunningException e) { e.printStackTrace(); } catch (ZooKeeperConnectionException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] agrs) { try { String tablename = "wishTest"; HBaseTest.dropTable(tablename); } catch (Exception e) { e.printStackTrace(); } }
结果：
table: wishTest删除成功！
package wish.hbase; import java.io.IOException; import java.util.ArrayList; import java.util.List; 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.ZooKeeperConnectionException; import org.apache.hadoop.hbase.client.Delete; 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.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.io.BatchUpdate; @SuppressWarnings("deprecation") public class HBaseTest { static HBaseConfiguration cfg = null; static { Configuration HBASE_CONFIG = new Configuration(); HBASE_CONFIG.set("hbase.zookeeper.quorum", "192.168.1.95"); HBASE_CONFIG.set("hbase.zookeeper.property.clientPort", "2181"); cfg = new HBaseConfiguration(HBASE_CONFIG); } /** * 创建一张表 */ public static void createTable(String tableName) { System.out.println("************start create table**********"); try { HBaseAdmin hBaseAdmin = new HBaseAdmin(cfg); if (hBaseAdmin.tableExists(tableName)) {// 如果存在要创建的表，那么先删除，再创建 hBaseAdmin.disableTable(tableName); hBaseAdmin.deleteTable(tableName); System.out.println(tableName + " is exist"); } HTableDescriptor tableDescriptor = new HTableDescriptor(tableName);// 代表表的schema tableDescriptor.addFamily(new HColumnDescriptor("name")); //增加列簇 tableDescriptor.addFamily(new HColumnDescriptor("age")); tableDescriptor.addFamily(new HColumnDescriptor("gender")); hBaseAdmin.createTable(tableDescriptor); } catch (MasterNotRunningException e) { e.printStackTrace(); } catch (ZooKeeperConnectionException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } System.out.println("*****end create table*************"); } /** * 插入数据 */ public static void insert(String tableName) { System.out.println("************start insert ************"); HTablePool pool = new HTablePool(cfg, 1000); //HTable table = (HTable) pool.getTable(tableName); Put put = new Put("2".getBytes());// 一个PUT代表一行数据，再NEW一个PUT表示第二行数据,每行一个唯一的ROWKEY，此处rowkey为put构造方法中传入的值 put.add("name".getBytes(), null, "rain".getBytes());// 本行数据的第一列 put.add("age".getBytes(), null, "20".getBytes());// 本行数据的第三列 put.add("gender".getBytes(), null, "female".getBytes());// 本行数据的第三列 try { pool.getTable(tableName).put(put); } catch (IOException e) { e.printStackTrace(); } System.out.println("************end insert************"); } /** * 查询所有数据 */ public static void queryAll(String tableName) { HTablePool pool = new HTablePool(cfg, 1000); try { ResultScanner rs = pool.getTable(tableName).getScanner(new Scan()); for (Result r : rs) { System.out.println("rowkey:" + new String(r.getRow())); for (KeyValue keyValue : r.raw()) { System.out.println("列：" + new String(keyValue.getFamily()) + " 值:" + new String(keyValue.getValue())); } } } catch (IOException e) { e.printStackTrace(); } } /* * 查询单条数据 */ public static void querySingle(String tableName) { HTablePool pool = new HTablePool(cfg, 1000); try { Get get = new Get("1".getBytes());// 根据rowkey查询 Result r = pool.getTable(tableName).get(get); System.out.println("rowkey:" + new String(r.getRow())); for (KeyValue keyValue : r.raw()) { System.out.println("列：" + new String(keyValue.getFamily()) + " 值:" + new String(keyValue.getValue())); } } catch (IOException e) { e.printStackTrace(); } } /* * 删除数据 */ public static void deleteRow(String tablename, String rowkey) { try { HTable table = new HTable(cfg, tablename); List list = new ArrayList(); Delete d1 = new Delete(rowkey.getBytes()); list.add(d1); table.delete(list); System.out.println("删除行成功!"); } catch (IOException e) { e.printStackTrace(); } } /* * 删除表 */ public static void dropTable(String tableName) { try { HBaseAdmin admin = new HBaseAdmin(cfg); admin.disableTable(tableName); admin.deleteTable(tableName); System.out.println("table: "+tableName+"删除成功！"); } catch (MasterNotRunningException e) { e.printStackTrace(); } catch (ZooKeeperConnectionException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] agrs) { try { String tablename = "wishTest"; HBaseTest.dropTable(tablename); } catch (Exception e) { e.printStackTrace(); } } }
HBase Java API使用（一）,布布扣,bubuko.com
标签：des style blog class code c
原文地址：http://www.cnblogs.com/wishyouhappy/p/3735077.html
