HbaseAPI笔记_大数据系统

hbaseAPI方法： API本质就是调用对象的方法去实现的。 ddl的概念是对表的操作和对外面的大的操作，ddl都是去调用admin对象的方法实现的admin对象通过连接.getAdmin获取。 dml的概念是对数据的操作和查询什么的，dml都是去调用Table对象的方法实现的，Table对象通过连接.getTable获取。步骤： ①获取hbase的配置对象 ②创建连接对象将配置对象传参 ③如果是ddl的话就通过连接调用getAdmin创建admin对象，dml就应该连接调用getTable ④然后就想要什么操作就调用admin对象的对应方法去操作，按照里面的参数去创建对应的参数。 hbase的ddl的API： ①判断表存在

public static boolean isTableExist(String tablename) throws IOException {
    boolean exits = admin.tableExists(TableName.valueOf(tablename));
    close(null,admin);
    return exits;
}

②创建表

public static void createTable(String tableName, String...cf) throws IOException {


    if(cf==null){
        System.out.println("输入列族");
    }
    if(isTableExist(tableName)){
        System.out.println("有这个表了");
    }


    HTableDescriptor hTableDescriptor = new HTableDescriptor(TableName.valueOf(tableName));


    for (String s : cf) {
        HColumnDescriptor hColumnDescriptor = new HColumnDescriptor(s);
        hTableDescriptor.addFamily(hColumnDescriptor);
    }


    admin.createTable(hTableDescriptor);


}

③创建命名空间

public static void createNameSpace(String ns){


    NamespaceDescriptor nss = NamespaceDescriptor.create(ns).build();
    try {
        admin.createNamespace(nss);
    } catch (NamespaceExistException e){
        System.out.println("命名空间存在了");
    } catch (IOException e) {
        e.printStackTrace();
    }


}

④删除表

public static void deleteTable(String tableName) throws IOException {
    if(!isTableExist(tableName)){
        System.out.println("表不存在");
    }
    admin.disableTable(TableName.valueOf(tableName));
    admin.deleteTable(TableName.valueOf(tableName));
}

ddl的全部代码：

package hbasetest;


import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
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.HbaseAdmin;


import java.io.IOException;




public class hbaseapi01 {


    private static Connection connection = null;
    private static Admin admin = null;
    static{
        try {
            Configuration configuration = HbaseConfiguration.create();
            configuration.set("hbase.zookeeper.quorum", "nn01,nn02,dn01,dn02,dn03");


            connection = ConnectionFactory.createConnection(configuration);
            admin = connection.getAdmin();
        }catch (Exception e){
            new RuntimeException(e);
        }
    }


    
    public static void close(Connection connection, Admin admin){
        if(admin!=null){
            try{
                admin.close();
            }catch (Exception e){
                new RuntimeException(e);
            }
        }
        if(connection!=null){
            try{
                connection.close();
            }catch (Exception e){
                new RuntimeException(e);
            }
        }
    }


    
    public static boolean isTableExist(String tablename) throws IOException {


        boolean exits = admin.tableExists(TableName.valueOf(tablename));


        close(null,admin);


        return exits;
    }


    
    public static void createTable(String tableName, String...cf) throws IOException {


        if(cf==null){
            System.out.println("输入列族");
        }
        if(isTableExist(tableName)){
            System.out.println("有这个表了");
        }


        HTableDescriptor hTableDescriptor = new HTableDescriptor(TableName.valueOf(tableName));


        for (String s : cf) {
            HColumnDescriptor hColumnDescriptor = new HColumnDescriptor(s);
            hTableDescriptor.addFamily(hColumnDescriptor);
        }


        admin.createTable(hTableDescriptor);


    }


    
    public static void deleteTable(String tableName) throws IOException {
        if(!isTableExist(tableName)){
            System.out.println("表不存在");
        }
        admin.disableTable(TableName.valueOf(tableName));
        admin.deleteTable(TableName.valueOf(tableName));
    }


    
    public static void createNameSpace(String ns){


        NamespaceDescriptor nss = NamespaceDescriptor.create(ns).build();
        try {
            admin.createNamespace(nss);
        } catch (NamespaceExistException e){
            System.out.println("命名空间存在了");
        } catch (IOException e) {
            e.printStackTrace();
        }


    }


    public static void main(String[] args) throws IOException {


        createNameSpace("ds1");






    }


}

hbase的dml的API ①插入数据

public static void putData(String tableNAme,String rowKey,String cf,String cn,String value) throws IOException {


    Table table = connection.getTable(TableName.valueOf(tableNAme));


    Put put = new Put(Bytes.toBytes(rowKey));

    put.addColumn(Bytes.toBytes(cf), Bytes.toBytes(cn), Bytes.toBytes(value));


    table.put(put);


    table.close();


}

②查询数据（get）

public static void getData(String tableName,String rowKey,String cf,String cn) throws IOException {


    Table table = connection.getTable(TableName.valueOf(tableName));
    
    Get get = new Get(Bytes.toBytes(rowKey));
    get.addColumn(Bytes.toBytes(cf),Bytes.toBytes(cn));
    
    Result result = table.get(get);
    
    for (Cell cell : result.rawCells()) {
        System.out.println("列族"+Bytes.toString(CellUtil.cloneFamily(cell))+"，列"+Bytes.toString(CellUtil.cloneQualifier(cell))+"，值："+Bytes.toString(CellUtil.clonevalue(cell)));
    }


}

③查询数据（scan）

public static void scanData(String tableName) throws IOException {
    Table table = connection.getTable(TableName.valueOf(tableName));
    Scan scan = new Scan();
    scan.setMaxVersions(10);
    ResultScanner scanner = table.getScanner(scan);
    for (Result result : scanner) {
        Cell[] cells = result.rawCells();
        for (Cell cell : cells) {
            System.out.println("rawkey"+Bytes.toString(CellUtil.cloneRow(cell))+",cf:"+Bytes.toString(CellUtil.cloneFamily(cell))+",cl:"+Bytes.toString(CellUtil.cloneQualifier(cell))+",value:"+Bytes.toString(CellUtil.clonevalue(cell)));
        }
    }
}

④删数据

public static void deleteData(String tablename,String rowkey,String cf,String cn) throws IOException {




    Table table = connection.getTable(TableName.valueOf(tablename));


    Delete delete = new Delete(Bytes.toBytes(rowkey));
    delete.addColumns(Bytes.toBytes(cf),Bytes.toBytes(cn));
    table.delete(delete);
    
    table.close();


}

dml的全部代码

package hbasetest;

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 dmlAPI {

    private static Connection connection = null;
    private static Admin admin = null;
    static{
        try {
            Configuration configuration = HbaseConfiguration.create();
            configuration.set("hbase.zookeeper.quorum", "nn01,nn02,dn01,dn02,dn03");

            connection = ConnectionFactory.createConnection(configuration);
            admin = connection.getAdmin();
        }catch (Exception e){
            new RuntimeException(e);
        }
    }

    
    public static void close(Connection connection, Admin admin){
        if(admin!=null){
            try{
                admin.close();
            }catch (Exception e){
                new RuntimeException(e);
            }
        }
        if(connection!=null){
            try{
                connection.close();
            }catch (Exception e){
                new RuntimeException(e);
            }
        }
    }

    
    public static void putData(String tableNAme,String rowKey,String cf,String cn,String value) throws IOException {

        Table table = connection.getTable(TableName.valueOf(tableNAme));

        Put put = new Put(Bytes.toBytes(rowKey));
        put.addColumn(Bytes.toBytes(cf), Bytes.toBytes(cn), Bytes.toBytes(value));

        table.put(put);

        table.close();

    }

    
    public static void getData(String tableName,String rowKey,String cf,String cn) throws IOException {

        Table table = connection.getTable(TableName.valueOf(tableName));

        Get get = new Get(Bytes.toBytes(rowKey));
        get.addColumn(Bytes.toBytes(cf),Bytes.toBytes(cn));

        Result result = table.get(get);

        for (Cell cell : result.rawCells()) {
            System.out.println("列族"+Bytes.toString(CellUtil.cloneFamily(cell))+"，列"+Bytes.toString(CellUtil.cloneQualifier(cell))+"，值："+Bytes.toString(CellUtil.clonevalue(cell)));
        }

    }

    public static void scanData(String tableName) throws IOException {
        Table table = connection.getTable(TableName.valueOf(tableName));
        Scan scan = new Scan();
        scan.setMaxVersions(10);
        ResultScanner scanner = table.getScanner(scan);
        for (Result result : scanner) {
            Cell[] cells = result.rawCells();
            for (Cell cell : cells) {
                System.out.println("rawkey"+Bytes.toString(CellUtil.cloneRow(cell))+",cf:"+Bytes.toString(CellUtil.cloneFamily(cell))+",cl:"+Bytes.toString(CellUtil.cloneQualifier(cell))+",value:"+Bytes.toString(CellUtil.clonevalue(cell)));
            }
        }
    }

    public static void deleteData(String tablename,String rowkey,String cf,String cn) throws IOException {


        Table table = connection.getTable(TableName.valueOf(tablename));

        Delete delete = new Delete(Bytes.toBytes(rowkey));
        delete.addColumns(Bytes.toBytes(cf),Bytes.toBytes(cn));
        table.delete(delete);

        table.close();

    }

    public static void main(String[] args) throws IOException {

//    getData("test","1001","cf","name");
        scanData("test");
    }

}

与mapreduce关联： map类

package hbasetest.mr2;

import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.mapreduce.Mapper;

import java.io.IOException;

public class mrMapper extends TableMapper {

@Override
protected void map(ImmutableBytesWritable key, Result value, Mapper.Context context) throws IOException, InterruptedException {

    Put put = new Put(value.getRow());

    for (Cell cell : value.rawCells()) {
        if("name".equals(Bytes.toString(CellUtil.cloneQualifier(cell)))){
            put.add(cell);
         }
    }
    context.write(key,put);

    }
}

reduce类

package hbasetest.mr2;

import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.mapreduce.Mapper;

import java.io.IOException;

public class mrMapper extends TableMapper {

@Override
protected void map(ImmutableBytesWritable key, Result value, Mapper.Context context) throws IOException, InterruptedException {

    Put put = new Put(value.getRow());

    for (Cell cell : value.rawCells()) {
        if("name".equals(Bytes.toString(CellUtil.cloneQualifier(cell)))){
            put.add(cell);
        }
    }
    context.write(key,put);

    }
}

driver类

package hbasetest.mr2;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HbaseConfiguration;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

public class mrDriver implements Tool {

    private Configuration conf = null;

    @Override
    public int run(String[] strings) throws Exception {

        Job job = Job.getInstance(conf);
        job.setJarByClass(mrDriver.class);
        TableMapReduceUtil.initTableMapperJob(strings[0],new Scan(),mrMapper.class,                                 
        ImmutableBytesWritable.class, Put.class,job);
        TableMapReduceUtil.initTableReducerJob(strings[1],mrReducer.class,job);
        boolean result = job.waitForCompletion(true);

        return result?0:1;
    }

    @Override
    public void setConf(Configuration configuration) {
        conf = configuration;
    }

    @Override
    public Configuration getConf() {
        return conf;
    }

    public static void main(String[] args) {
        try {
            Configuration conf = HbaseConfiguration.create();
            ToolRunner.run(conf,new mrDriver(),args);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

打包后提交到集群运行的命令 yarn jar jar包名驱动类名参数 hbase知识点：预分区：三种创建方法：第一种传递一个数组来分区第二种创建15个分区然后以16进制字符串划分第三种写一个文件里面是命名规则然后划分（会对文件先排序）

HbaseAPI笔记

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