• HBase Java客户端编程


    本文以HBase 0.90.2为例,介绍如何在Windows系统,Eclipse IDE集成环境下,使用Java语言,进行HBase客户端编程,包含建立表、删除表、插入记录、删除记录、各种方式下的查询操作等。

    1. 准备工作

    1、下载后安装jdk包(这里使用的是jdk-6u10-rc2-bin-b32-windows-i586-p-12_sep_2008);

    2、下载eclipse,解压到本地(这里使用的是eclipse-java-helios-SR2-win32);

    3、下载HBase包,解压安装包到本地(这里使用的是hbase-0.90.2)。

    2. 搭建开发环境

    1、运行Eclipse,创建一个新的Java工程“HBaseClient”,右键项目根目录,选择 “Properties”->“Java Build Path”->“Library”->“Add External JARs”,将HBase解压后根目录下的hbase-0.90.2.jar、hbase-0.90.2-tests.jar和lib子目录下所有jar 包添加到本工程的Classpath下。

    2、按照步骤1中的操作,将自己所连接的HBase的配置文件hbase-site.xml添加到本工程的Classpath中,如下所示为配置文件的一个示例:

    1. <configuration>
    2. <property>
    3. <name>hbase.rootdir</name>
    4. <value>hdfs://hostname:9000/hbase</value>
    5. </property>
    6. <property>
    7. <name>hbase.cluster.distributed</name>
    8. <value>true</value>
    9. </property>
    10. <property>
    11. <name>hbase.zookeeper.quorum</name>
    12. <value>*.*.*.*, *.*.*.*, *.*.*.*</value>
    13. </property>
    14. <property skipInDoc="true">
    15. <name>hbase.defaults.for.version</name>
    16. <value>0.90.2</value>
    17. </property>
    18. </configuration>

    3、下面可以在Eclipse环境下进行HBase编程了。

    3. HBase基本操作代码示例

    3.1 初始化配置

    1 privatestatic Configuration conf =null;
    2 /**
    3 * 初始化配置
    4 */
    5 static {
    6 conf = HBaseConfiguration.create();
    7 }

    3.2 创建表

    1. /**
    2. * 创建表操作
    3. * @throws IOException
    4. */
    5. publicvoid createTable(String tablename, String[] cfs) throws IOException {
    6. HBaseAdmin admin =new HBaseAdmin(conf);
    7. if (admin.tableExists(tablename)) {
    8. System.out.println("表已经存在!");
    9. }
    10. else {
    11. HTableDescriptor tableDesc =new HTableDescriptor(tablename);
    12. for (int i =0; i < cfs.length; i++) {
    13. tableDesc.addFamily(new HColumnDescriptor(cfs[i]));
    14. }
    15. admin.createTable(tableDesc);
    16. System.out.println("表创建成功!");
    17. }
    18. }

    3.3 删除表

     1 /**
    2 * 删除表操作
    3 * @param tablename
    4 * @throws IOException
    5 */
    6 publicvoid deleteTable(String tablename) throws IOException {
    7 try {
    8 HBaseAdmin admin =new HBaseAdmin(conf);
    9 admin.disableTable(tablename);
    10 admin.deleteTable(tablename);
    11 System.out.println("表删除成功!");
    12 } catch (MasterNotRunningException e) {
    13 e.printStackTrace();
    14 } catch (ZooKeeperConnectionException e) {
    15 e.printStackTrace();
    16 }
    17 }

    3.4 插入一行记录

    1. /**
    2. * 插入一行记录
    3. * @param tablename
    4. * @param cfs
    5. */
    6. publicvoid writeRow(String tablename, String[] cfs) {
    7. try {
    8. HTable table =new HTable(conf, tablename);
    9. Put put =new Put(Bytes.toBytes("rows1"));
    10. for (int j =0; j < cfs.length; j++) {
    11. put.add(Bytes.toBytes(cfs[j]),
    12. Bytes.toBytes(String.valueOf(1)),
    13. Bytes.toBytes("value_1"));
    14. table.put(put);
    15. }
    16. } catch (IOException e) {
    17. e.printStackTrace();
    18. }
    19. }

    3.5 删除一行记录

     1 /**
    2 * 删除一行记录
    3 * @param tablename
    4 * @param rowkey
    5 * @throws IOException
    6 */
    7 publicvoid deleteRow(String tablename, String rowkey) throws IOException {
    8 HTable table =new HTable(conf, tablename);
    9 List list =new ArrayList();
    10 Delete d1 =new Delete(rowkey.getBytes());
    11 list.add(d1);
    12 table.delete(list);
    13 System.out.println("删除行成功!");
    14 }

    3.6 查找一行记录

    1. /**
    2. * 查找一行记录
    3. * @param tablename
    4. * @param rowkey
    5. */
    6. publicstaticvoid selectRow(String tablename, String rowKey)
    7. throws IOException {
    8. HTable table =new HTable(conf, tablename);
    9. Get g =new Get(rowKey.getBytes());
    10. Result rs = table.get(g);
    11. for (KeyValue kv : rs.raw()) {
    12. System.out.print(new String(kv.getRow()) +"");
    13. System.out.print(new String(kv.getFamily()) +":");
    14. System.out.print(new String(kv.getQualifier()) +"");
    15. System.out.print(kv.getTimestamp() +"");
    16. System.out.println(new String(kv.getValue()));
    17. }
    18. }

    3.7 查询表中所有行

     1 /**
    2 * 查询表中所有行
    3 * @param tablename
    4 */
    5 publicvoid scaner(String tablename) {
    6 try {
    7 HTable table =new HTable(conf, tablename);
    8 Scan s =new Scan();
    9 ResultScanner rs = table.getScanner(s);
    10 for (Result r : rs) {
    11 KeyValue[] kv = r.raw();
    12 for (int i =0; i < kv.length; i++) {
    13 System.out.print(new String(kv[i].getRow()) +"");
    14 System.out.print(new String(kv[i].getFamily()) +":");
    15 System.out.print(new String(kv[i].getQualifier()) +"");
    16 System.out.print(kv[i].getTimestamp() +"");
    17 System.out.println(new String(kv[i].getValue()));
    18 }
    19 }
    20 } catch (IOException e) {
    21 e.printStackTrace();
    22 }
    23 }

    转自:http://www.cnblogs.com/panfeng412/archive/2011/08/14/2137984.html

    第二个例子

    package com.hbase;
    
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    
    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.KeyValue;
    import org.apache.hadoop.hbase.MasterNotRunningException;
    import org.apache.hadoop.hbase.ZooKeeperConnectionException;
    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.util.Bytes;
    
    public class HbaseClient {
    
    	private static Configuration conf = null;
    	    
    	/**
    	 * hbase-0.90.3
    	 * 初始化配置
    	 */
    	static {
    		conf = HBaseConfiguration.create();
    		conf.set("hbase.master", "192.168.27.12");
    	}
    
    	/**
    	 * 创建表操作
    	 * 
    	 * @throws IOException
    	 */
    	public void createTable(String tablename, String[] cfs) throws IOException {
    		HBaseAdmin admin = new HBaseAdmin(conf);
    		if (admin.tableExists(tablename)) {
    			System.out.println("表已经存在!");
    		} else {
    			HTableDescriptor tableDesc = new HTableDescriptor(tablename);
    			for (int i = 0; i < cfs.length; i++) {
    				tableDesc.addFamily(new HColumnDescriptor(cfs[i]));
    			}
    			admin.createTable(tableDesc);
    			System.out.println(" 表创建成功!");
    		}
    	}
    
    	/**
    	 * 删除表操作
    	 * 
    	 * @param tablename
    	 * @throws IOException
    	 */
    	public void deleteTable(String tablename) throws IOException {
    		try {
    			HBaseAdmin admin = new HBaseAdmin(conf);
    			if (!admin.tableExists(tablename)) {
    				System.out.println("表不存在, 无需进行删除操作!");
    			}else{
    				admin.disableTable(tablename);
    				admin.deleteTable(tablename);
    				System.out.println(" 表删除成功!");
    			}
    		} catch (MasterNotRunningException e) {
    			e.printStackTrace();
    		} catch (ZooKeeperConnectionException e) {
    			e.printStackTrace();
    		}
    	}
    
    	public void insertRow() throws Exception{
             HTable table = new HTable(conf, "test");
             Put put = new Put(Bytes.toBytes("row3"));
             put.add(Bytes.toBytes("cf"), Bytes.toBytes("444"), Bytes.toBytes("value444"));
             table.put(put);
    	}
    	
    	/**
    	 * 插入一行记录
    	 * 
    	 * @param tablename
    	 * @param cfs
    	 */
    	public void writeRow(String tablename, String[] cfs) {
    		try {
    			HTable table = new HTable(conf, tablename);
    			Put put = new Put(Bytes.toBytes("rows3"));
    			for (int j = 0; j < cfs.length; j++) {
    				put.add(Bytes.toBytes(cfs[j]),
    						Bytes.toBytes(cfs[j]+String.valueOf(1)),
    						Bytes.toBytes(cfs[j]+"value"));
    				
    				table.put(put);
    			}
    			System.out.println("写入成功!");
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    
    	//写多条记录
    	public void writeMultRow(String tablename, String[][] cfs) {
    		try {
    			HTable table = new HTable(conf, tablename);
    			List<Put> lists = new ArrayList<Put>();
    			for (int i = 0; i < cfs.length; i++) {
    				Put put = new Put(Bytes.toBytes(cfs[i][0]));
    				put.add(Bytes.toBytes(cfs[i][1]),
    						Bytes.toBytes(cfs[i][2]),
    						Bytes.toBytes(cfs[i][3]));
    				lists.add(put);
    			}
    			table.put(lists);
    			System.out.println("写入成功!");
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    	
    	/**
    	 * 删除一行记录
    	 * 
    	 * @param tablename
    	 * @param rowkey
    	 * @throws IOException
    	 */
    	public void deleteRow(String tablename, String rowkey) throws IOException {
    		HTable table = new HTable(conf, tablename);
    		List<Delete> list = new ArrayList<Delete>();
    		Delete d1 = new Delete(rowkey.getBytes());
    		list.add(d1);
    		table.delete(list);
    		System.out.println("删除行成功!");
    	}
    
    	/**
    	 * 查找一行记录
    	 * 
    	 * @param tablename
    	 * @param rowkey
    	 */
    	public static void selectRow(String tablename, String rowKey)
    			throws IOException {
    		HTable table = new HTable(conf, tablename);
    		Get g = new Get(rowKey.getBytes());
    //		g.addColumn(Bytes.toBytes("cf:1"));
    		Result rs = table.get(g);
    		for (KeyValue kv : rs.raw()) {
    			System.out.print(new String(kv.getRow()) + "  ");
    			System.out.print(new String(kv.getFamily()) + ":");
    			System.out.print(new String(kv.getQualifier()) + "  ");
    			System.out.print(kv.getTimestamp() + "  ");
    			System.out.println(new String(kv.getValue()));
    		}
    	}
    
    	/**
    	 * 查询表中所有行
    	 * 
    	 * @param tablename
    	 */
    	public void scaner(String tablename) {
    		try {
    			HTable table = new HTable(conf, tablename);
    			Scan s = new Scan();
    			ResultScanner rs = table.getScanner(s);
    			for (Result r : rs) {
    				KeyValue[] kv = r.raw();
    				for (int i = 0; i < kv.length; i++) {
    					System.out.print(new String(kv[i].getRow()) + "  ");
    					System.out.print(new String(kv[i].getFamily()) + ":");
    					System.out.print(new String(kv[i].getQualifier()) + "  ");
    					System.out.print(kv[i].getTimestamp() + "  ");
    					System.out.println(new String(kv[i].getValue()));
    				}
    			}
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    
    	public static void main(String[] args) throws Exception {
    		HbaseClient cli = new HbaseClient();
    		
    		//删除表
    		cli.deleteTable("test");
    		
    		//创建表
    		cli.createTable("test", new String[]{"cf"});
    		
    		
    		//写多条记录
    		cli.writeMultRow("test", new String[][]{{"rows1","cf","1","value1"},{"rows1","cf","2","value2"},{"rows2","cf","2","value2"}});
    		
    		//写一条记录
    		cli.writeRow("test", new String[]{"cf"});
    
    		System.out.println("\n查询一个rows1:");
    		selectRow("test", "rows1");
    		
    		System.out.println("\n查询所有:");
    		cli.scaner("test");
    		
    	}
    }
    

    转自: http://blog.csdn.net/renren000/article/details/6662595

    文档信息

    作者:一个农夫 ( www.cnblogs.com/afarmer )

    欢迎转载,请保留文档信息。

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  • 原文地址:https://www.cnblogs.com/afarmer/p/2455484.html
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