Hbase shell+api操作

Hbase shell操作

命名	描述	语法
help ‘命令名’	查看命令的使用描述	help ‘命令名’
whoami	我是谁	whoami
version	返回hbase版本信息	version
status	返回hbase集群的状态信息	status
table_help	查看如何操作表	table_help
create	创建表	create ‘表名’, ‘列族名1’, ‘列族名2’, ‘列族名N’
alter	修改列族	添加一个列族：alter ‘表名’, ‘列族名’删除列族：alter ‘表名’, {NAME=> ‘列族名’, METHOD=> ‘delete’}
describe	显示表相关的详细信息	describe ‘表名’
list	列出hbase中存在的所有表	list
exists	测试表是否存在	exists ‘表名’
put	添加或修改的表的值	put ‘表名’, ‘行键’, ‘列族名’, ‘列值’put ‘表名’, ‘行键’, ‘列族名:列名’, ‘列值’
scan	通过对表的扫描来获取对用的值	scan ‘表名 扫描某个列族： scan ‘表名’, {COLUMN=>‘列族名’}扫描某个列族的某个列： scan ‘表名’, {COLUMN=>‘列族名:列名’}查询同一个列族的多个列： scan ‘表名’, {COLUMNS => [ ‘列族名1:列名1’, ‘列族名1:列名2’, …]}
get	获取行或单元（cell）的值	get ‘表名’, ‘行键’get ‘表名’, ‘行键’, ‘列族名’
count	统计表中行的数量	count ‘表名’
incr	增加指定表行或列的值	incr ‘表名’, ‘行键’, ‘列族:列名’, 步长值
get_counter	获取计数器	get_counter ‘表名’, ‘行键’, ‘列族:列名’
delete	删除指定对象的值（可以为表，行，列对应的值，另外也可以指定时间戳的值）	删除列族的某个列： delete ‘表名’, ‘行键’, ‘列族名:列名’
deleteall	删除指定行的所有元素值	deleteall ‘表名’, ‘行键’
truncate	重新创建指定表	truncate ‘表名’
enable	使表有效	enable ‘表名’
is_enabled	是否启用	is_enabled ‘表名’
disable	使表无效	disable ‘表名’
is_disabled	是否无效	is_disabled ‘表名’
drop	删除表	drop的表必须是disable的 disable ‘表名’ drop ‘表名’
shutdown	关闭hbase集群（与exit不同）
tools	列出hbase所支持的工具
exit	退出hbase shell

Hbase api 操作

package cn.itcast.hbase.admin.api_test;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Test;
import java.io.IOException;
import java.util.List;

/**
 * @author noor9
 * @date 2020-10-18-22:49
 */
public class TableTest {

    private static Connection connection;
    private static Admin admin;
    //获取连接
    public static void getConn() throws IOException {
        Configuration configuration = HBaseConfiguration.create();
        connection = ConnectionFactory.createConnection(configuration);
        admin = connection.getAdmin();

    }
    //关闭连接
    public static void closeConn(){
        try{
            if(admin != null){
                admin.close();
            }
            if(null != connection){
                connection.close();
            }
        }catch (IOException e){
            e.printStackTrace();
        }
    }
    //创建表  fields 存放列簇
    public static void createTable(String tableName , String[] fields) throws IOException {
        getConn();
        TableName TableName1 = TableName.valueOf(tableName);
        if (admin.tableExists(TableName1))
        {
            System.out.println("表已经存在");
            deleteTable(tableName);
            TableDescriptorBuilder tableDescriptorBuilder = TableDescriptorBuilder.newBuilder(TableName1);
            for (String field : fields) {
                ColumnFamilyDescriptorBuilder columnFamilyDescriptorBuilder = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(field));
                ColumnFamilyDescriptor cfDes = columnFamilyDescriptorBuilder.build();
                tableDescriptorBuilder.setColumnFamily(cfDes);
            }
            TableDescriptor tableDescriptor = tableDescriptorBuilder.build();
            admin.createTable(tableDescriptor);
        }
        else {
            TableDescriptorBuilder tableDescriptorBuilder = TableDescriptorBuilder.newBuilder(TableName1);
            for (String field : fields) {
                ColumnFamilyDescriptorBuilder columnFamilyDescriptorBuilder = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(field));
                ColumnFamilyDescriptor cfDes = columnFamilyDescriptorBuilder.build();
                tableDescriptorBuilder.setColumnFamily(cfDes);
             }
            TableDescriptor tableDescriptor = tableDescriptorBuilder.build();
            admin.createTable(tableDescriptor);
            System.out.println("创建成功");
        }
        closeConn();
    }
    
    //添加数据
    public static void addRecord(String tableName ,String row , String[] fields ,String[] values) throws IOException {
        getConn();
        TableName tableName1 = TableName.valueOf(tableName);
        if(!admin.tableExists(tableName1))
        {
            System.err.println("the table "+tableName+" is not exist");
            System.exit(1);
        }
        else{
            Table table = connection.getTable(tableName1);
            for (int i = 0 ; i!=fields.length ; i++)
            {
                Put put = new Put(Bytes.toBytes(row));
                String[] cols = fields[i].split(":");

                put.addColumn(Bytes.toBytes(cols[0]),Bytes.toBytes(cols[1]),Bytes.toBytes(values[i]));
                table.put(put);
            }
            table.close();
        }
        closeConn();
    }
    
    //查找
    public static void scanColumn(String tableName , String rowkey , String column) throws IOException {
        getConn();
        TableName tableName1 = TableName.valueOf(tableName);
        Table table = connection.getTable(tableName1);
        if(!column.contains(":")){
            Get get = new Get(Bytes.toBytes(rowkey));
            Result result = table.get(get);
            // 列出所有单元格
            List<Cell> cells = result.listCells();
            // 打印rowkey
            byte[] row = result.getRow();
            System.out.println(Bytes.toString(row));
            // 迭代单元格列表
            for (Cell cell : cells) {
                //获取列簇名称
                String cf = Bytes.toString(cell.getFamilyArray(), cell.getFamilyOffset(), cell.getFamilyLength());
                //获取列的名称
                String columnName = Bytes.toString(cell.getQualifierArray(), cell.getQualifierOffset(), cell.getQualifierLength());
                //获取值
                String value = Bytes.toString(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength());
                if(value=="")
                    System.out.println(cf+":"+columnName+"->"+null);
                else
                    System.out.println(cf+":"+columnName+"->"+value);
            }
        }else{
            Get get = new Get(Bytes.toBytes(rowkey));
            String  family= column.split(":")[0];
            String qualifier = column.split(":")[1];
            get.addColumn(Bytes.toBytes(family),Bytes.toBytes(qualifier));
            Result result = table.get(get);
            String resultValue =new String(result.getValue(Bytes.toBytes(family), Bytes.toBytes(qualifier)));
            if(resultValue=="")
                System.out.println(family+":"+qualifier+"->"+null);
            else
                System.out.println(family+":"+qualifier+"->"+resultValue.toString());
        }
        table.close();
        closeConn();
    }
    //修改值
    public static void modifyData(String tableName, String rowkey, String column , String value) throws IOException {
        getConn();
        TableName tableName1 = TableName.valueOf(tableName);
        Table table = connection.getTable(tableName1);
        Put put = new Put(Bytes.toBytes(rowkey));
        String family = column.split(":")[0];
        String qualifier = column.split(":")[1];
        //修改
        put.addColumn(Bytes.toBytes(family),Bytes.toBytes(qualifier),Bytes.toBytes(value));
        table.put(put);
        //比对
        Get get = new Get(Bytes.toBytes(rowkey));
        get.addColumn(Bytes.toBytes(family),Bytes.toBytes(qualifier));
        Result result = table.get(get);
        String resultValue =new String(result.getValue(Bytes.toBytes(family), Bytes.toBytes(qualifier)));
        if(resultValue.equals(value))
            System.out.println("修改成功");
        table.close();
        closeConn();
    }
    
    //删除表
    public static void deleteTable(String tableName) throws IOException {
        getConn();
        TableName tableName1 = TableName.valueOf(tableName);
        if(admin.tableExists(tableName1))
        {
            admin.disableTable(tableName1);
            admin.deleteTable(tableName1);
        }
        System.out.println("删除表成功");
    }
    
    //删除行
    public static void deleteRow(String tableName ,String row) throws IOException {
        getConn();
        if(!admin.tableExists(TableName.valueOf(tableName)))
        {
            System.err.println("the table "+tableName+" is not exist");
            System.exit(1);
        }
        Table table = connection.getTable(TableName.valueOf(tableName));
        Delete delete = new Delete(Bytes.toBytes(row));//rowkey
        table.delete(delete);
        System.out.println("删除成功");
        table.close();
        closeConn();
    }

    //根据表名查询所有的rowkey
    public static void getRowKey(String tableName) throws IOException {
        getConn();
        Table table = connection.getTable(TableName.valueOf(tableName));
        Scan scan = new Scan();
        ResultScanner results = table.getScanner(scan);
        for (Result result : results) {
            byte[] row = result.getRow();
            System.out.println("标记");
            System.out.println(new String(row));
        }
        closeConn();
    }
    
    public static void main(String[] args) throws IOException {
        String tableName = "Student";
        String tableName2 = "Course";
        String tableName3 = "SC";
        //1.第一个
        /*String[] fields = {"H1","H2","H3"};
        createTable(tableName,fields);*/
        //第二个
        /*String row = "Zhangsan";
        String[] fields ={"H1:S_No", "H1:S_Name", "H1:S_Sex","H1:S_Age"};
        String[] values={"2015001","Zhangsan","male","23"};
        addRecord(tableName,row,fields,values);*/
        //第三个
        // canColumn(tableName,"Zhangsan","H1:S_Age");

        //第四个 modifyData(String tableName, String row, String column)
        //modifyData(tableName , "Zhangsan" , "H1:S_Age","21");

        //第五个
        //deleteRow(tableName , "Zhangsan");
        //getRowKey(tableName);
    }
}