甘道夫Eclipse+Maven搭建HBase开发环境及HBaseDAO代码演示样例

Posted 2021-01-23 ldxsuanfa

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环境：

Win764bit

Eclipse Version: Kepler Service Release 1

java version "1.7.0_40"

第一步：Eclipse中新建Maven项目。编辑pom.xml并更新下载jar包

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

<groupId>fulong.bigdata</groupId>

<artifactId>myHbase</artifactId>

<version>0.0.1-SNAPSHOT</version>

<groupId>org.apache.hbase</groupId>

<artifactId>hbase-client</artifactId>

<version>0.96.2-hadoop2</version>

</dependency>

<groupId>org.apache.hadoop</groupId>

<artifactId>hadoop-hdfs</artifactId>

</dependency>

<groupId>jdk.tools</groupId>

<artifactId>jdk.tools</artifactId>

<scope>system</scope>

<systemPath>${JAVA_HOME}/lib/tools.jar</systemPath>

</dependency>

</dependencies>

</project>

第二步：将目标集群的Hadoop和HBase配置文件复制到project中

目的是为了让project能找到Zookeeper及Hbase Master。

配置文件在project中的路径为：

/src/main/resources/hadoop

/src/main/resources/hbase

然后将这两个文件夹加入进project的classpath中：

终于文件夹结构例如以下：

第三步：hbase-site.xml中加入

<value>org.apache.hadoop.hdfs.DistributedFileSystem</value>

</property>

第四步：编写Java程序调用Hbase接口

该代码包括了部分经常使用HBase接口。

package myHbase;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
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.filter.Filter;
import org.apache.hadoop.hbase.util.Bytes;
public class HBaseDAO {
    
    static Configuration conf = HBaseConfiguration.create();
    /**
     * create a table :table_name(columnFamily) 
     * @param tablename
     * @param columnFamily
     * @throws Exception
     */
    public static void createTable(String tablename, String columnFamily) throws Exception {
        HBaseAdmin admin = new HBaseAdmin(conf);
        if(admin.tableExists(tablename)) {
            System.out.println("Table exists!");
            System.exit(0);
        }
        else {
            HTableDescriptor tableDesc = new HTableDescriptor(TableName.valueOf(tablename));
            tableDesc.addFamily(new HColumnDescriptor(columnFamily));
            admin.createTable(tableDesc);
            System.out.println("create table success!");
        }
        admin.close();
        
    }
    
    /**
     * delete table ,caution!!!!!! ,dangerous!!!!!!
     * @param tablename
     * @return
     * @throws IOException
     */
    public static boolean deleteTable(String tablename) throws IOException {
        HBaseAdmin admin = new HBaseAdmin(conf);
        if(admin.tableExists(tablename)) {
            try {
                admin.disableTable(tablename);
                admin.deleteTable(tablename);
            } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
                admin.close();
                return false;
            }
        }
        admin.close();
        return true;
    }
    /**
     * put a cell data into a row identified by rowKey,columnFamily,identifier 
     * @param HTable, create by : HTable table = new HTable(conf, "tablename")
     * @param rowKey
     * @param columnFamily
     * @param identifier
     * @param data
     * @throws Exception
     */
    public static void putCell(HTable table, String rowKey, String columnFamily, String identifier, String data) throws Exception{
        Put p1 = new Put(Bytes.toBytes(rowKey));
        p1.add(Bytes.toBytes(columnFamily), Bytes.toBytes(identifier), Bytes.toBytes(data));
        table.put(p1);
        System.out.println("put ‘"+rowKey+"‘, ‘"+columnFamily+":"+identifier+"‘, ‘"+data+"‘");
    }
    
    /**
     * get a row identified by rowkey
     * @param HTable, create by : HTable table = new HTable(conf, "tablename")
     * @param rowKey
     * @throws Exception
     */
    public static Result getRow(HTable table, String rowKey) throws Exception {
        Get get = new Get(Bytes.toBytes(rowKey));
        Result result = table.get(get);
        System.out.println("Get: "+result);
        return result;
    }
    
    /**
     * delete a row identified by rowkey
     * @param HTable, create by : HTable table = new HTable(conf, "tablename")
     * @param rowKey
     * @throws Exception
     */
    public static void deleteRow(HTable table, String rowKey) throws Exception {
        Delete delete = new Delete(Bytes.toBytes(rowKey));
        table.delete(delete);
        System.out.println("Delete row: "+rowKey);
    }
    
    /**
     * return all row from a table
     * @param HTable, create by : HTable table = new HTable(conf, "tablename")
     * @throws Exception
     */
    public static ResultScanner scanAll(HTable table) throws Exception {
        Scan s =new Scan();
        ResultScanner rs = table.getScanner(s);
        return rs;
    }
    
    /**
     * return a range of rows specified by startrow and endrow
     * @param HTable, create by : HTable table = new HTable(conf, "tablename")
     * @param startrow
     * @param endrow
     * @throws Exception
     */
    public static ResultScanner scanRange(HTable table,String startrow,String endrow) throws Exception {
        Scan s =new Scan(Bytes.toBytes(startrow),Bytes.toBytes(endrow));
        ResultScanner rs = table.getScanner(s);
        return rs;
    }
    /**
     * return a range of rows filtered by specified condition
     * @param HTable, create by : HTable table = new HTable(conf, "tablename")
     * @param startrow
     * @param filter
     * @throws Exception
     */
    public static ResultScanner scanFilter(HTable table,String startrow, Filter filter) throws Exception {
        Scan s =new Scan(Bytes.toBytes(startrow),filter);
        ResultScanner rs = table.getScanner(s);
        return rs;
    }
    
    public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub

        HTable table = new HTable(conf, "apitable");
        
//      ResultScanner rs = HBaseDAO.scanRange(table, "2013-07-10*", "2013-07-11*");
//    	ResultScanner rs = HBaseDAO.scanRange(table, "100001", "100003");
    	ResultScanner rs = HBaseDAO.scanAll(table);

    	for(Result r:rs) {
    		System.out.println("Scan: "+r);
    	}
    	table.close();
    	

//      HBaseDAO.createTable("apitable", "testcf");
//      HBaseDAO.putRow("apitable", "100001", "testcf", "name", "liyang");
//      HBaseDAO.putRow("apitable", "100003", "testcf", "name", "leon");
//    	HBaseDAO.deleteRow("apitable", "100002");
//    	HBaseDAO.getRow("apitable", "100003");
//    	HBaseDAO.deleteTable("apitable");
        
    }
}

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