目录
(一)练习常用的HBase Shell命令
1、启动HBase
先启动HDFS 再启动HBase
进入shell交互式执行环境
2、练习shell命令
create scan list describe alter
put
get
delete
drop
删除表前要disable它
关于NoSQL数据库中的列族和列
这些数据库允许你以非常灵活的方式存储和检索数据
hbase_35">3、关闭hbase服务
(二)HBase 常用的Java API 及应用实例
hbase_39">1、启动hbase服务
2、启动eclipse
java_project_43">3、新建java project
导入jar包
导入/usr/local/hbase/lib中的所有jar包
再导入/usr/local/hbase/lib/client-facing-thirdparty中的所有jar 包
创建类文件
常用Java API:
java">import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import java.io.IOException;public class ExampleForHBase {public static Configuration configuration;public static Connection connection;public static Admin admin;public static void main(String[] args) throws IOException {init();createTable("student", new String[]{"score"});insertData("student", "zhangsan", "score", "English", "69");insertData("student", "zhangsan", "score", "Math", "86");insertData("student", "zhangsan", "score", "Computer", "77");getData("student", "zhangsan", "score", "English");close();}public static void init() {configuration = HBaseConfiguration.create();configuration.set("hbase.rootdir", "hdfs://localhost:9000/hbase");try {connection = ConnectionFactory.createConnection(configuration);admin = connection.getAdmin();} catch (IOException e) {e.printStackTrace();}}public static void close() {try {if (admin != null) {admin.close();}if (connection != null) {connection.close();}} catch (IOException e) {e.printStackTrace();}}public static void createTable(String myTableName, String[] colFamily) throws IOException {TableName tableName = TableName.valueOf(myTableName);if (admin.tableExists(tableName)) {System.out.println("table is exists!");} else {TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tableName);for (String str : colFamily) {ColumnFamilyDescriptor family = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(str)).build();tableDescriptor.setColumnFamily(family);}admin.createTable(tableDescriptor.build());}}public static void insertData(String tableName, String rowKey, String colFamily, String col, String val) throws IOException {Table table = connection.getTable(TableName.valueOf(tableName));Put put = new Put(rowKey.getBytes());put.addColumn(Bytes.toBytes(colFamily), Bytes.toBytes(col), Bytes.toBytes(val));table.put(put);table.close();}public static void getData(String tableName, String rowKey, String colFamily, String col) throws IOException {Table table = connection.getTable(TableName.valueOf(tableName));Get get = new Get(rowKey.getBytes());get.addColumn(Bytes.toBytes(colFamily), Bytes.toBytes(col));Result result = table.get(get);System.out.println(new String(result.getValue(Bytes.toBytes(colFamily), Bytes.toBytes(col))));table.close();}
}
run——>run as application
hbase_shell_134">打开hbase shell
list scan