HBase 操作与编程使用
1.任务：
- 列出HBase所有的表的相关信息，例如表名；
- 在终端打印出指定的表的所有记录数据；
- 向已经创建好的表添加和删除指定的列族或列；
- 清空指定的表的所有记录数据；
- 统计表的行数。
2.关系型数据库中的表和数据（教材P92上)，要求将其转换为适合于HBase存储的表并插入数据。
创建表
‘Student’表中添加数据插入数据
‘Course’表中添加数据
‘SC’表中添加数据
3. 编程完成以下指定功能（教材P92下)：
（1）createTable(String tableName, String[] fields)创建表。
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
import org.apache.hadoop.hbase.util.Bytes;
import java.io.IOException;
public class CreateTable {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
public static void init(){//建立连接
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(){//关闭连接
try{
if(admin != null){
admin.close();
}
if(connection != null){
connection.close();
}
}catch(IOException e){
e.printStackTrace();
}
}
public static void createTable(String tableName,String[] fields) throws IOException{
init();
TableName tablename = TableName.valueOf(tableName);//定义表名
if(admin.tableExists(tablename)){
System.out.println("table is exists!");
admin.disableTable(tablename);
admin.deleteTable(tablename);
}
TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tablename);
for(int i=0;i<fields.length;i++){
ColumnFamilyDescriptor family = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(fields[i])).build();
tableDescriptor.setColumnFamily(family);
}
admin.createTable(tableDescriptor.build());
close();
}
public static void main(String[] args){
String[] fields = {"id","score"};
try{
createTable("test",fields);
}catch(IOException e){
e.printStackTrace();
}
}
}
（2）addRecord(String tableName, String row, String[] fields, String[] values)
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
public class addRecord {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
public static void init(){//建立连接
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(){//关闭连接
try{
if(admin != null){
admin.close();
}
if(connection != null){
connection.close();
}
}catch(IOException e){
e.printStackTrace();
}
}
public static void addRecord(String tableName,String row,String[] fields,String[] values) throws IOException{
init();//连接Hbase
Table table = connection.getTable(TableName.valueOf(tableName));//表连接
Put put = new Put(row.getBytes());//创建put对象
for(int i=0;i<fields.length;i++){
String[] cols = fields[i].split(":");
if(cols.length == 1){
put.addColumn(fields[i].getBytes(),"".getBytes(),values[i].getBytes());
}
else{
put.addColumn(cols[0].getBytes(),cols[1].getBytes(),values[i].getBytes());
}
table.put(put);//向表中添加数据
}
close();//关闭连接
}
public static void main(String[] args){
String[] fields = {"Score:Math","Score:Computer Science","Score:English"};
String[] values = {"90","90","90"};
try{
addRecord("grade","S_Name",fields,values);
}catch(IOException e){
e.printStackTrace();
}
}
}
（3）scanColumn(String tableName, String column)
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Get;
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.client.Table;
import org.apache.hadoop.hbase.util.Bytes;
public class scanColumn {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
public static void init(){//建立连接
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(){//关闭连接
try{
if(admin != null){
admin.close();
}
if(connection != null){
connection.close();
}
}catch(IOException e){
e.printStackTrace();
}
}
public static void showResult(Result result){
Cell[] cells = result.rawCells();
for(int i=0;i<cells.length;i++){
System.out.println("RowName:"+new String(CellUtil.cloneRow(cells[i])));//打印行键
System.out.println("ColumnName:"+new String(CellUtil.cloneQualifier(cells[i])));//打印列名
System.out.println("Value:"+new String(CellUtil.cloneValue(cells[i])));//打印值
System.out.println("Column Family:"+new String(CellUtil.cloneFamily(cells[i])));//打印列簇
System.out.println();
}
}
public static void scanColumn(String tableName,String column){
init();
try {
Table table = connection.getTable(TableName.valueOf(tableName));
Scan scan = new Scan();
scan.addFamily(Bytes.toBytes(column));
ResultScanner scanner = table.getScanner(scan);
for(Result result = scanner.next();result != null;result = scanner.next()){
showResult(result);
}
} catch (IOException e) {
e.printStackTrace();
}
finally{
close();
}
}
public static void main(String[] args){
scanColumn("Student","S_Age");
}
}
（4）modifyData(String tableName, String row, String column)
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
public class modifyData {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
public static void init(){//建立连接
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(){//关闭连接
try{
if(admin != null){
admin.close();
}
if(connection != null){
connection.close();
}
}catch(IOException e){
e.printStackTrace();
}
}
public static void modifyData(String tableName,String row,String column,String value) throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Put put = new Put(row.getBytes());
String[] cols = column.split(":");
if(cols.length == 1){
put.addColumn(column.getBytes(),"".getBytes(), value.getBytes());
}
else{
put.addColumn(cols[0].getBytes(), cols[1].getBytes(), value.getBytes());
}
table.put(put);
close();
}
public static void main(String[] args){
try{
modifyData("Student","1","S_Name","Tom");
}
catch(Exception e){
e.printStackTrace();
}
}
}
（5）deleteRow(String tableName, String row)
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Table;
public class deleteRow {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
public static void init(){//建立连接
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(){//关闭连接
try{
if(admin != null){
admin.close();
}
if(connection != null){
connection.close();
}
}catch(IOException e){
e.printStackTrace();
}
}
public static void deleteRow(String tableName,String row) throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Delete delete = new Delete(row.getBytes());
table.delete(delete);
close();
}
public static void main(String[] args){
try{
deleteRow("Student","3");
}catch(Exception e){
e.printStackTrace();
}
}
}
