Hbase java API 实现增删改查

迷南。 2022-10-17 04:19 178阅读 0赞

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[Hadoop集群搭建及配置⑧——Hbase的安装配置][Hadoop_Hbase]

[eclipse连接Hadoop][eclipse_Hadoop]

[eclipse 实现 Hdfs java API][eclipse _ Hdfs java API]

[简单熟悉HDFS的常用命令][HDFS]

[eclipse 实现 HBase java API][eclipse _ HBase java API]

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上一章介绍了 Hbase API的核心类，这章主要实现HBase的增删改查功能。看代码：

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;
    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;
    
    public class HBaseTest {
        
    	//初始化Configuration对象
    	private Configuration conf = null;
    	//初始化连接
    	private Connection conn = null;
    
    	public void init() throws Exception {
        
    		//获取Configuration对象
    		conf = HBaseConfiguration.create();
    		//对于hbase的客户端来说，只需要知道hbase所经过的Zookeeper集群地址即可
    		//因为hbase的客户端找hbase读写数据完全不用经过HMaster
    		//        conf.set("hbase.zookeeper.quorum", "master:2181,salve1:2181,slave2:2181");
    		conf.set("hbase.rootdir","hdfs://192.168.142.128:8020/hbase");
    		conf.set("hbase.master","hdfs://192.168.142.128:60000");
    		conf.set("hbase.zookeeper.property.clientPort","2181");
    		conf.set("hbase.zookeeper.quorum","master,slave1,slave2");
    		//获取连接
    		conn = ConnectionFactory.createConnection(conf);
    	}
    
    	public void createTable() throws Exception {
        
    		//获取表管理器对象
    		Admin admin = conn.getAdmin();
    		//创建表的描述对象，并指定表名
    		HTableDescriptor tableDescriptor = new HTableDescriptor(TableName.valueOf("user_info".getBytes()));
    		//构造第一个列族描述对象，并指定列族名
    		HColumnDescriptor hcd1 = new HColumnDescriptor("base_info");
    		//构造第二个列族描述对象，并指定列族名
    		HColumnDescriptor hcd2 = new HColumnDescriptor("extra_info");
    		//为该列族设定一个版本数量，最小为1，最大为3
    		hcd2.setVersions(1, 3);
    		//将列族描述对象添加到表描述对象中
    		tableDescriptor.addFamily(hcd1).addFamily(hcd2);
    		//利用表管理器来创建表
    		admin.createTable(tableDescriptor);
    		
    		//关闭
    		admin.close();
    		System.out.println("创建表成功");
    	}
    
    	public void testPut() throws Exception {
        
    		//创建table对象，通过table对象来添加数据
    		Table table = conn.getTable(TableName.valueOf("user_info"));
    		//创建一个集合，用于存放Put对象
    		ArrayList<Put> puts = new ArrayList<Put>();
    		//构建put对象（kv形式），并指定其行键
    		Put put01 = new Put(Bytes.toBytes("user001"));
    		put01.addColumn(Bytes.toBytes("base_info"),Bytes.toBytes("username"), Bytes.toBytes("zhangsan"));
    		put01.addColumn(Bytes.toBytes("base_info"),Bytes.toBytes("password"), Bytes.toBytes("123456"));
    		
    		Put put02 = new Put("user002".getBytes());
    		put02.addColumn(Bytes.toBytes("base_info"),Bytes.toBytes("username"), Bytes.toBytes("lisi"));
    		put02.addColumn(Bytes.toBytes("extra_info"),Bytes.toBytes("married"), Bytes.toBytes("false"));
    		
    		// 把所有的put对象添加到一个集合中
    		puts.add(put01);
    		puts.add(put02);
    		// 提交所有的插入数据的记录
    		table.put(puts);
    		
    		// 关闭
    		table.close();
    		System.out.println("添加数据成功");
    	}
    
    	public void testGet() throws IOException {
        
    		Table table = conn.getTable(TableName.valueOf("user_info"));
    		Get get = new Get("user001".getBytes());
    		// 使用HTable得到resultcanner实现类的对象
    		Result result1 = table.get(get);
    		List<Cell> cells = result1.listCells();
    		for (Cell cell : cells) {
        
    			//得到rowkey
    			System.out.println("行键:" + Bytes.toString(CellUtil.cloneRow(cell)));
    			//得到列族
    			System.out.println("列族:" + Bytes.toString(CellUtil.cloneFamily(cell)));
    			System.out.println("列:" + Bytes.toString(CellUtil.cloneQualifier(cell)));
    			System.out.println("值:" + Bytes.toString(CellUtil.cloneValue(cell)));
    			System.out.println("----------------------******----------------------");
    		}
    	}
    
    	public void testScan() throws Exception {
        
    		//获取table对象
    		Table table = conn.getTable(TableName.valueOf("user_info"));
    		//获取scan对象
    		Scan scan = new Scan();
    		//获取查询的数据
    		ResultScanner scanner = table.getScanner(scan);
    		//获取ResultScanner所有数据，返回迭代器
    		Iterator<Result> iter = scanner.iterator();
    		//遍历迭代器
    		while (iter.hasNext()) {
        
    			// 获取当前每一行结果数据
    			Result result = iter.next();
    			// 获取当前每一行中所有的cell对象
    			List<Cell> cells = result.listCells();
    			// 迭代所有的cell
    			for(Cell c:cells){
        
    				//获取行键
    				byte[] rowArray = c.getRowArray();
    				// 获取列族
    				byte[] familyArray = c.getFamilyArray();
    				// 获取列族下的列名称
    				byte[] qualifierArray = c.getQualifierArray();
    				// 列字段的值
    				byte[] valueArray = c.getValueArray();
    				// 打印rowArray、familyArray、qualifierArray、valueArray
    				System.out.print("行键:"+new String(rowArray, c.getRowOffset(),c.getRowLength()));
    				System.out.print(" 列族:"+new String(familyArray,c.getFamilyOffset(),c.getFamilyLength()));
    				System.out.print(" 列:"+ new String(qualifierArray,c.getQualifierOffset(), c.getQualifierLength()));
    				System.out.println(" 值:"+ new String(valueArray,c.getValueOffset(), c.getValueLength()));
    			}
    			System.out.println("-----------------------");
    		}
    		//关闭
    		table.close();
    	}
    
    	public void testDel() throws Exception {
        
    		//获取table对象
    		Table table = conn.getTable(TableName.valueOf("user_info"));
    		//获取delete对象,需要一个rowkey
    		Delete delete = new Delete("user001".getBytes());
    		//在delete对象中指定要删除的列族-列名称
    		delete.addColumn("base_info".getBytes(), "password".getBytes());
    		//执行删除操作
    		table.delete(delete);
    		System.out.println("删除列成功");
    		//关闭
    		table.close();
    	}
    
    	public void testDrop() throws Exception {
        
    		//获取一个表的管理器
    		Admin admin = conn.getAdmin();
    		//删除表时先需要disable，将表置为不可用，然后在delete
    		admin.disableTable(TableName.valueOf("user_info"));
    		admin.deleteTable(TableName.valueOf("user_info"));
    		System.out.println("删除表成功");
    		//关闭
    		admin.close();
    
    	}
    	
    	public static void main(String arg[]) throws Exception {
        
    		HBaseTest test = new HBaseTest();
    		test.init();
    		test.createTable();
    		test.testPut();
    		test.testGet();
    		test.testScan();
    	}
    }

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调用方法，实现完毕。

[Hadoop_Hbase]: https://blog.csdn.net/weixin_44775255/article/details/114676669
[eclipse_Hadoop]: https://blog.csdn.net/weixin_44775255/article/details/114799064
[eclipse _ Hdfs java API]: https://blog.csdn.net/weixin_44775255/article/details/114809298
[HDFS]: https://blog.csdn.net/weixin_44775255/article/details/115067406
[eclipse _ HBase java API]: https://blog.csdn.net/weixin_44775255/article/details/114821297
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDc3NTI1NQ_size_16_color_FFFFFF_t_70 1]: /images/20221014/aac5b6159ce34921b0badf9a1779c563.png