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’,
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’,
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);
    }
}