1、搭建环境
新建JAVA项目,添加的包有:
有关Hadoop的hadoop-core-0.20.204.0.jar
有关Hbase的hbase-0.90.4.jar、hbase-0.90.4-tests.jar以及Hbase资源包中lib目录下的所有jar包
2、主要程序
Java代码
- package com.wujintao.hbase.test;
- 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.filter.Filter;
- import org.apache.hadoop.hbase.filter.FilterList;
- import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
- import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
- import org.apache.hadoop.hbase.util.Bytes;
- public class JinTaoTest {
- public static Configuration configuration;
- static {
- configuration = HBaseConfiguration.create();
- configuration.set("hbase.zookeeper.property.clientPort", "2181");
- configuration.set("hbase.zookeeper.quorum", "192.168.1.100");
- configuration.set("hbase.master", "192.168.1.100:600000");
- }
- public static void main(String[] args) {
- // createTable("wujintao");
- // insertData("wujintao");
- // QueryAll("wujintao");
- // QueryByCondition1("wujintao");
- // QueryByCondition2("wujintao");
- //QueryByCondition3("wujintao");
- //deleteRow("wujintao","abcdef");
- deleteByCondition("wujintao","abcdef");
- }
- /**
- * 创建表
- * @param tableName
- */
- public static void createTable(String tableName) {
- System.out.println("start create table ......");
- try {
- HBaseAdmin hBaseAdmin = new HBaseAdmin(configuration);
- 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,detele....");
- }
- HTableDescriptor tableDescriptor = new HTableDescriptor(tableName);
- tableDescriptor.addFamily(new HColumnDescriptor("column1"));
- tableDescriptor.addFamily(new HColumnDescriptor("column2"));
- tableDescriptor.addFamily(new HColumnDescriptor("column3"));
- 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
- * @param tableName
- */
- public static void insertData(String tableName) {
- System.out.println("start insert data ......");
- HTablePool pool = new HTablePool(configuration, 1000);
- HTable table = (HTable) pool.getTable(tableName);
- Put put = new Put("112233bbbcccc".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("column1".getBytes(), null, "aaa".getBytes());// 本行数据的第一列
- put.add("column2".getBytes(), null, "bbb".getBytes());// 本行数据的第三列
- put.add("column3".getBytes(), null, "ccc".getBytes());// 本行数据的第三列
- try {
- table.put(put);
- } catch (IOException e) {
- e.printStackTrace();
- }
- System.out.println("end insert data ......");
- }
- /**
- * 删除一张表
- * @param tableName
- */
- public static void dropTable(String tableName) {
- try {
- HBaseAdmin admin = new HBaseAdmin(configuration);
- admin.disableTable(tableName);
- admin.deleteTable(tableName);
- } catch (MasterNotRunningException e) {
- e.printStackTrace();
- } catch (ZooKeeperConnectionException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- * 根据 rowkey删除一条记录
- * @param tablename
- * @param rowkey
- */
- public static void deleteRow(String tablename, String rowkey) {
- try {
- HTable table = new HTable(configuration, 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();
- }
- }
- /**
- * 组合条件删除
- * @param tablename
- * @param rowkey
- */
- public static void deleteByCondition(String tablename, String rowkey) {
- //目前还没有发现有效的API能够实现 根据非rowkey的条件删除 这个功能能,还有清空表全部数据的API操作
- }
- /**
- * 查询所有数据
- * @param tableName
- */
- public static void QueryAll(String tableName) {
- HTablePool pool = new HTablePool(configuration, 1000);
- HTable table = (HTable) pool.getTable(tableName);
- try {
- ResultScanner rs = table.getScanner(new Scan());
- for (Result r : rs) {
- System.out.println("获得到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();
- }
- }
- /**
- * 单条件查询,根据rowkey查询唯一一条记录
- * @param tableName
- */
- public static void QueryByCondition1(String tableName) {
- HTablePool pool = new HTablePool(configuration, 1000);
- HTable table = (HTable) pool.getTable(tableName);
- try {
- Get scan = new Get("abcdef".getBytes());// 根据rowkey查询
- Result r = table.get(scan);
- System.out.println("获得到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();
- }
- }
- /**
- * 单条件按查询,查询多条记录
- * @param tableName
- */
- public static void QueryByCondition2(String tableName) {
- try {
- HTablePool pool = new HTablePool(configuration, 1000);
- HTable table = (HTable) pool.getTable(tableName);
- Filter filter = new SingleColumnValueFilter(Bytes
- .toBytes("column1"), null, CompareOp.EQUAL, Bytes
- .toBytes("aaa")); // 当列column1的值为aaa时进行查询
- Scan s = new Scan();
- s.setFilter(filter);
- ResultScanner rs = table.getScanner(s);
- for (Result r : rs) {
- System.out.println("获得到rowkey:" + new String(r.getRow()));
- for (KeyValue keyValue : r.raw()) {
- System.out.println("列:" + new String(keyValue.getFamily())
- + "====值:" + new String(keyValue.getValue()));
- }
- }
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- /**
- * 组合条件查询
- * @param tableName
- */
- public static void QueryByCondition3(String tableName) {
- try {
- HTablePool pool = new HTablePool(configuration, 1000);
- HTable table = (HTable) pool.getTable(tableName);
- List<Filter> filters = new ArrayList<Filter>();
- Filter filter1 = new SingleColumnValueFilter(Bytes
- .toBytes("column1"), null, CompareOp.EQUAL, Bytes
- .toBytes("aaa"));
- filters.add(filter1);
- Filter filter2 = new SingleColumnValueFilter(Bytes
- .toBytes("column2"), null, CompareOp.EQUAL, Bytes
- .toBytes("bbb"));
- filters.add(filter2);
- Filter filter3 = new SingleColumnValueFilter(Bytes
- .toBytes("column3"), null, CompareOp.EQUAL, Bytes
- .toBytes("ccc"));
- filters.add(filter3);
- FilterList filterList1 = new FilterList(filters);
- Scan scan = new Scan();
- scan.setFilter(filterList1);
- ResultScanner rs = table.getScanner(scan);
- for (Result r : rs) {
- System.out.println("获得到rowkey:" + new String(r.getRow()));
- for (KeyValue keyValue : r.raw()) {
- System.out.println("列:" + new String(keyValue.getFamily())
- + "====值:" + new String(keyValue.getValue()));
- }
- }
- rs.close();
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- }
注意:可能大家没看到更新数据的操作,其实更新的操作跟添加完全一致,只不过是添加呢rowkey不存在,更新呢rowkey已经存在,并且timstamp相同的情况下,还有就是目前好像还没办法实现hbase数据的分页查询,不知道有没有人知道怎么做
HBase性能优化建议:
针对前面的代码,有很多不足之处,在此我就不修改上面的代码了,只是提出建议的地方,大家自己加上
1)配置
当你调用create方法时将会加载两个配置文件:hbase-default.xml and hbase-site.xml,利用的是当前的java类路径, 代码中configuration设置的这些配置将会覆盖hbase-default.xml和hbase-site.xml中相同的配置,如果两个配置 文件都存在并且都设置好了相应参上面的属性下面的属性即可
2)关于建表
public void createTable(HTableDescriptor desc)
HTableDescriptor 代表的是表的schema, 提供的方法中比较有用的有
setMaxFileSize,指定最大的region size
setMemStoreFlushSize 指定memstore flush到HDFS上的文件大小
增加family通过 addFamily方法
public void addFamily(final HColumnDescriptor family)
HColumnDescriptor代表的是column的schema,提供的方法比较常用的有
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。
setMaxVersions:指定数据最大保存的版本个数。默认为3。
注意的是,一般我们不去setInMemory为true,默认是关闭的
3)关于入库
官方建议
table.setAutoFlush(false); //数据入库之前先设置此项为false
table.setflushCommits();//入库完成后,手动刷入数据
注意:
在入库过程中,put.setWriteToWAL(true/flase);
关于这一项如果不希望大量数据在存储过程中丢失,建议设置为true,如果仅是在测试演练阶段,为了节省入库时间建议设置为false
4)关于获取表实例
HTablePool pool = new HTablePool(configuration, Integer.MAX_VALUE);
HTable table = (HTable) pool.getTable(tableName);
建议用表连接池的方式获取表,具体池有什么作用,我想用过数据库连接池的同学都知道,我就不再重复
不建议使用new HTable(configuration,tableName);的方式获取表
5)关于查询
建议每个查询语句都放入try catch语句块,并且finally中要进行关闭ResultScanner实例以及将不使用的表重新放入到HTablePool中的操作,具体做法如下
Java代码
- public static void QueryAll(String tableName) {
- HTablePool pool = new HTablePool(configuration, Integer.MAX_VALUE);
- HTable table = null;
- ResultScanner rs = null;
- try {
- Scan scan = new Scan();
- table = (HTable) pool.getTable(tableName);
- rs = table.getScanner(scan);
- for (Result r : rs) {
- System.out.println("获得到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();
- }finally{
- rs.close();// 最后还得关闭
- pool.putTable(table); //实际应用过程中,pool获取实例的方式应该抽取为单例模式的,不应在每个方法都重新获取一次(单例明白?就是抽取到专门获取pool的逻辑类中,具体逻辑为如果pool存在着直接使用,如果不存在则new)
- }
- }
所以,以上代码有缺陷的地方,感兴趣的同学可以针对优化建议作出相应修改