HBase 基本Java API

数据库：HBaseConfiguration  HBaseAdmin  

表：HTable  HTableDescriptor

列族：HColumnDescriptor

行列操作：Put  Get  Scanner

HBaseConfiguration:

Configuration create()

//从classpath中查找hbase-site.xml初始化Configuration，如果没有，默认读取HBase-版本号.jar中的默认配置文件

void merger(Configuration destConf, Configuration srcConf)  //合并两个Configuration

用法：Configuration config = HBaseConfiguration.create();

HBaseAdmin:

管理HBase数据库信息，可以创建表、删除表、列出表项、使表有效或无效、添加删除列族

void addColumn (String tableName, HColumnDescriptor column)  //添加列族

void checkHBaseAvailable (HBaseConfiguration conf)  //查看HBase状态，静态函数

void createTable (HTableDescriptor desc)  //创建一个新表，同步操作

void deleteTable (byte[] tableName) //删除表

void enableTable (byte[] tableName) //使表有效

void disableTable (byte[] tableName) //使表无效

HTableDescriptor[] listTable()  //列出所有用户空间表项

void modifyTable (byte[] tableName, HTableDescriptor htd)  //修改表模式，异步操作，耗时

boolean tableExists (String tableName); //检查表是否存在

用法：HBaseAdmin admin = new HBaseAdmin(config);    admin.disableTable(Bytes.toBytes("tablename"));

HTableDescriptor:

包含了表的名字及列族

void addFamily (HColumnDescriptor cdesc)  //添加一个列族

HColumnDescriptor removeFamily ( byte[] column)  //移除一个列族

byte[] getName ()  //获取表名

byte[] getValue (byte[] key)  //获取属性值

void setValue (String key, String value )  //设置属性值

用法：

HTableDescriptor htd = new HTableDescriptor ("tableName");

htd.addFamily (new HColumnDescriptor("Family"));

HColumnDescriptor:

维护列族信息，如版本号、压缩设置等，通常在创建表或添加列族时使用

列族被创建后不能直接修改，只能删除后重建

列族被删除后，对应数据一同被删除

byte[] getName()  //获取列族名字

byte[] getValue()  //获取对应属性值

void setValue (String key, String value)  //设置对应属性值

HTable:

用来与HBase表进行通信，非线程安全，若有多个线程，使用HTablePool

void checkAndPut (byte[] row, byte[] family, byte[] quaalifier, byte[] value, Put put)  //自动检查row/family/qualifier/是否与给定的值匹配

void close()  //释放资源

boolean exists (Get get)  //检查get锁指定的值是否存在

Result get(Get get)  //取出指定行的某些单元格对应的值

byte[][] getEndKeys ()  //获取表每个Region的结束键值

ResultScanner getScanner (byte[] family)  //获取给定列族的Scanner实例

HTableDescriptor getTableDescriptor()  //获取当前表的HTableDescriptor实例

byte[] getTableName()  //获取表名

void put (Put put)  //向表中添加值

用法：

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

ResultScanner scanner = table.getScanner (Bytes.toBytes("cf"));

Put:

添加数据

Put add (byte[] family, byte[] quaalifier, byte[] value)

Put add (byte[] family, byte[] quaalifier, long ts, byte[] value)

List<Key Value> get (byte[] family, byte[] qualifier)  //返回与指定 列族:列 匹配的项

boolean has (byte[] family, byte[] qualifier)  //检查是否有 列族:列

用法：

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

Put p = new Put(Bytes.toBytes("row")); //为指定行建一个Put操作

p.add(Bytes.toBytes("family"), Bytes.toBytes("qulifier"), Bytes.toBytes("tvalue"));

table.put(p);

Get:

获取单行信息

Get addColumn (byte[] family, byte[] qualifier)  

Get addFamily (byte[] family)

Get setTimeRange (long minStamp, long maxStamp)

Get setFilter (Filter filter)

用法：

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

Get g = new Get(Bytes.toBytes("row")); //为指定行建一个Get操作

Result result = table.get(g);

Result:

存储Get或Scan操作后获取的表的单行值

boolean containsColumn (byte[] family, byte[] qualifier)

NavigableMap<byte[], byte[]> getFamilyMap (byte[] family)  //返回列族的qulifier:value们

byte[] getValue (byte[] family, byte[] qualifier) 

ResultScanner:

void close()

Result next()

用法：

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

for ( Result rowResult : scanner ) 

    byte[] str = rowResult.getValue ( Bytes.toBytes("family"), Bytes.toBytes("column") )

import java.util.List;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.Cell;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.TableName;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.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.filter.BinaryComparator;import org.apache.hadoop.hbase.filter.BinaryPrefixComparator;import org.apache.hadoop.hbase.filter.ByteArrayComparable;import org.apache.hadoop.hbase.filter.ColumnPrefixFilter;import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;import org.apache.hadoop.hbase.filter.FamilyFilter;import org.apache.hadoop.hbase.filter.Filter;import org.apache.hadoop.hbase.filter.MultipleColumnPrefixFilter;import org.apache.hadoop.hbase.filter.PrefixFilter;import org.apache.hadoop.hbase.filter.QualifierFilter;import org.apache.hadoop.hbase.filter.RegexStringComparator;import org.apache.hadoop.hbase.filter.RowFilter;import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;import org.apache.hadoop.hbase.filter.SubstringComparator;import org.apache.hadoop.hbase.master.TableNamespaceManager;import org.apache.hadoop.hbase.util.Bytes;import org.junit.Before;import org.junit.Test;public class HbaseDemo {private Configuration conf = null;@Beforepublic void init(){conf = HBaseConfiguration.create();conf.set("hbase.zookeeper.quorum", "hdp0,hdp1,hdp2");}@Testpublic void testDrop() throws Exception{HBaseAdmin admin = new HBaseAdmin(conf);admin.disableTable("account");admin.deleteTable("account");admin.close();}@Testpublic void testPut() throws Exception{HTable table = new HTable(conf, "person_info");Put p = new Put(Bytes.toBytes("person_rk_bj_zhang_000002"));p.add("base_info".getBytes(), "name".getBytes(), "zhangwuji".getBytes());table.put(p);table.close();}@Testpublic void testGet() throws Exception{HTable table = new HTable(conf, "person_info");Get get = new Get(Bytes.toBytes("person_rk_bj_zhang_000001"));get.setMaxVersions(5);Result result = table.get(get);List<Cell> cells = result.listCells();//result.getValue(family, qualifier);  可以从result中直接取出一个特定的value//遍历出result中所有的键值对for(KeyValue kv : result.list()){String family = new String(kv.getFamily());System.out.println(family);String qualifier = new String(kv.getQualifier());System.out.println(qualifier);System.out.println(new String(kv.getValue()));}table.close();}/** * 多种过滤条件的使用方法 * @throws Exception */@Testpublic void testScan() throws Exception{HTable table = new HTable(conf, "person_info".getBytes());Scan scan = new Scan(Bytes.toBytes("person_rk_bj_zhang_000001"), Bytes.toBytes("person_rk_bj_zhang_000002"));//前缀过滤器----针对行键Filter filter = new PrefixFilter(Bytes.toBytes("rk"));//行过滤器ByteArrayComparable rowComparator = new BinaryComparator(Bytes.toBytes("person_rk_bj_zhang_000001"));RowFilter rf = new RowFilter(CompareOp.LESS_OR_EQUAL, rowComparator);/**                * 假设rowkey格式为：创建日期_发布日期_ID_TITLE                * 目标：查找  发布日期  为  2014-12-21  的数据                 */                rf = new RowFilter(CompareOp.EQUAL , new SubstringComparator("_2014-12-21_"));//单值过滤器 1 完整匹配字节数组new SingleColumnValueFilter("base_info".getBytes(), "name".getBytes(), CompareOp.EQUAL, "zhangsan".getBytes());//单值过滤器2 匹配正则表达式ByteArrayComparable comparator = new RegexStringComparator("zhang.");new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(), CompareOp.EQUAL, comparator);//单值过滤器2 匹配是否包含子串,大小写不敏感comparator = new SubstringComparator("wu");new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(), CompareOp.EQUAL, comparator);//键值对元数据过滤-----family过滤----字节数组完整匹配                FamilyFilter ff = new FamilyFilter(                CompareOp.EQUAL ,                 new BinaryComparator(Bytes.toBytes("base_info"))   //表中不存在inf列族，过滤结果为空                );                //键值对元数据过滤-----family过滤----字节数组前缀匹配                ff = new FamilyFilter(                CompareOp.EQUAL ,                 new BinaryPrefixComparator(Bytes.toBytes("inf"))   //表中存在以inf打头的列族info，过滤结果为该列族所有行                );                       //键值对元数据过滤-----qualifier过滤----字节数组完整匹配                        filter = new QualifierFilter(                CompareOp.EQUAL ,                 new BinaryComparator(Bytes.toBytes("na"))   //表中不存在na列，过滤结果为空                );                filter = new QualifierFilter(                CompareOp.EQUAL ,                 new BinaryPrefixComparator(Bytes.toBytes("na"))   //表中存在以na打头的列name，过滤结果为所有行的该列数据        );               //基于列名(即Qualifier)前缀过滤数据的ColumnPrefixFilter               filter = new ColumnPrefixFilter("na".getBytes());                       //基于列名(即Qualifier)多个前缀过滤数据的MultipleColumnPrefixFilter               byte[][] prefixes = new byte[][] {Bytes.toBytes("na"), Bytes.toBytes("me")};               filter = new MultipleColumnPrefixFilter(prefixes);                //为查询设置过滤条件               scan.setFilter(filter);                scan.addFamily(Bytes.toBytes("base_info"));ResultScanner scanner = table.getScanner(scan);for(Result r : scanner){/**for(KeyValue kv : r.list()){String family = new String(kv.getFamily());System.out.println(family);String qualifier = new String(kv.getQualifier());System.out.println(qualifier);System.out.println(new String(kv.getValue()));}*///直接从result中取到某个特定的valuebyte[] value = r.getValue(Bytes.toBytes("base_info"), Bytes.toBytes("name"));System.out.println(new String(value));}table.close();}@Testpublic void testDel() throws Exception{HTable table = new HTable(conf, "user");Delete del = new Delete(Bytes.toBytes("rk0001"));del.deleteColumn(Bytes.toBytes("data"), Bytes.toBytes("pic"));table.delete(del);table.close();}public static void main(String[] args) throws Exception {Configuration conf = HBaseConfiguration.create();conf.set("hbase.zookeeper.quorum", "hdp0:2181,hdp1:2181,hdp2:2181");HBaseAdmin admin = new HBaseAdmin(conf);TableName tableName = TableName.valueOf("person_info");HTableDescriptor td = new HTableDescriptor(tableName);HColumnDescriptor cd = new HColumnDescriptor("base_info");cd.setMaxVersions(10);td.addFamily(cd);admin.createTable(td);admin.close();}}