hbase的java客户端

hbase提供了java客户端去操作数据，我们通过创建一个maven项目来实现简单的数据操作。

• pom.xml添加hbase插件

  <dependency>
  	<groupId>org.apache.hbase</groupId>
  	<artifactId>hbase-client</artifactId>
  	<version>1.3.1</version>
  </dependency>
  <dependency>
      <groupId>org.apache.hbase</groupId>
      <artifactId>hbase-server</artifactId>
      <version>1.3.1</version>
  </dependency>
      <dependency>
      <groupId>org.apache.hbase</groupId>
      <artifactId>hbase-common</artifactId>
      <version>1.3.1</version>
  </dependency>
  <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.2</version>
  </dependency>
  <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
  </dependency>
  

• java代码

  • 创建一个学生类

  public class Student{
  	private Integer id;
  	private String name;
  	private String age;
  	
  	create getter and setter ...
  	
  	create toString ...
  	
  }
  

  • 创建一个HBaseDemo类

  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.Cell;
  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.Admin;
  import org.apache.hadoop.hbase.client.Connection;
  import org.apache.hadoop.hbase.client.ConnectionFactory;
  import org.apache.hadoop.hbase.client.Delete;
  import org.apache.hadoop.hbase.client.Get;
  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.client.Table;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.guoyu.hbase.entry.Student;
  
  public class HBaseDemo {
  
  	private static Logger logger = LoggerFactory.getLogger(HBaseDemo.class);
  	private static Admin admin;
  
  	public static void main(String[] args) throws IOException {
  		//System.out.println("hhhh");
  //		boolean flag = createTable("dbtest:user_table",new String[] {"information","contact"});
  //		if(flag) {
  //			System.out.println("创建成功");
  //		}
  		
  		//插入和更新数据
  //		Student stu = new Student();
  //		stu.setId(1);
  //		stu.setName("xiaoxin");
  //		stu.setAge("18");
  //		insertData("dbtest:student",stu);
  //		System.out.println("插入成功");
  		
  		Student stu = getDataByRowKey("dbtest:student","1");
  		System.out.println(stu.toString());
  		
  		String name = getCellData("dbtest:student","1","info","name");
  		System.out.println(name);
  		logger.info("student查询成功");
  		
  		List<Student> students = getAllData("dbtest:student");
  		students.forEach(System.out::println);
  		//deleteByRowKey("dbtest:student","student-1");
  		//logger.info("删除成功");
  		
  		deleteTable("dbtest:user_table");
  		logger.info("删除表成功");
  		
  	}
  
  	// 创建HBase的连接
  	public static Connection initHBase() throws IOException {
  
  		Configuration conf = HBaseConfiguration.create();
  		conf.set("hbase.zookeeper.property.clientPort", "2181");
  		conf.set("hbase.zookeeper.quorum", "hadoop2,hadoop3,hadoop4");
  		conf.set("hbase.master", "hadoop2:60000");
  		Connection connection = ConnectionFactory.createConnection();
  		return connection;
  
  	}
  
  	// 创建表
  	public static boolean createTable(String tableName, String[] cols) throws IOException {
  		TableName table = TableName.valueOf(tableName);
  		admin = initHBase().getAdmin();
  
  		if (admin.tableExists(table)) {
  			System.out.println("表已存在！");
  			return false;
  		} else {
  			HTableDescriptor hTableDescriptor = new HTableDescriptor(tableName);
  			for (String col : cols) {
  				HColumnDescriptor hColumnDescriptor = new HColumnDescriptor(col);
  				hTableDescriptor.addFamily(hColumnDescriptor);
  			}
  			admin.createTable(hTableDescriptor);
  			return true;
  		}
  	}
  	
  	//更新或插入数据
  	public static void insertData(String tableName, Student stu) throws IOException {
  		TableName table = TableName.valueOf(tableName);
  		Put put = new Put((stu.getId()+"").getBytes());
  		put.addColumn("info".getBytes(), "name".getBytes(), stu.getName().getBytes());
  		put.addColumn("info".getBytes(), "age".getBytes(), stu.getAge().getBytes());
  		Table tab = initHBase().getTable(table);
  		tab.put(put);
  		System.out.println("插入成功");
  	}
  	
  	//根据rowKey进行查询
  	public static Student getDataByRowKey(String tableName, String rowKey) throws IOException {
  		Table table = initHBase().getTable(TableName.valueOf(tableName));
  		Get get = new Get(rowKey.getBytes());
  		Student stu = new Student();
  		stu.setId(Integer.valueOf(rowKey));
  		if(!get.isCheckExistenceOnly()) {
  			Result result = table.get(get);
  			for(Cell cell : result.rawCells()) {
  				String colName = Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(),cell.getQualifierLength());
  				String value = Bytes.toString(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength());
  				if(colName.equals("name")){
                      stu.setName(value);
                  }
                  if(colName.equals("age")){
                      stu.setAge(value);
                  }
  
  			}
  		}
  		return stu;
  	}
  	
  	//查询制定单cell内容
  	public static String getCellData(String tableName,String rowKey,String family,String col) {
  		try {
  			Table table = initHBase().getTable(TableName.valueOf(tableName));
              String result = null;
              Get get = new Get(rowKey.getBytes());
              if(!get.isCheckExistenceOnly()){
                  get.addColumn(Bytes.toBytes(family),Bytes.toBytes(col));
                  Result res = table.get(get);
                  byte[] resByte = res.getValue(Bytes.toBytes(family), Bytes.toBytes(col));
                  return result = Bytes.toString(resByte);
              }else{
                  return result = "查询结果不存在";
              }
  
  		}catch(Exception e) {
  			e.printStackTrace();
  		}
  		return "出现异常";
  	}
  	
  	public static List<Student> getAllData(String tableName){
  		Table table = null;
  		List<Student> list = new ArrayList<Student>();
  		try {
  			table = initHBase().getTable(TableName.valueOf(tableName));
  			ResultScanner results = table.getScanner(new Scan());
  			Student stu = null;
  			for(Result result : results) {
  				String id = new String(result.getRow());
  				System.out.println("用户名："+new String(result.getRow()));
  				stu = new Student();
  				for(Cell cell : result.rawCells()) {
  					String row = Bytes.toString(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength());
  					String colName = Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(),cell.getQualifierLength());
  					String value = Bytes.toString(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength());
                      stu.setId(Integer.valueOf(row));
                      if(colName.equals("name")){
                           stu.setName(value);
                      }
                      if(colName.equals("age")){
                           stu.setAge(value);
                      }
                      
  				}
  				list.add(stu);
  			}
  		}catch(Exception e) {
  			e.printStackTrace();
  		}
  		return list;
  	}
  	
  	//删除指定cell数据
  	public static void deleteByRowKey(String tableName, String rowKey) throws IOException {
  		Table table = initHBase().getTable(TableName.valueOf(tableName));
  		Delete delete = new Delete(Bytes.toBytes(rowKey));
  		table.delete(delete);
  	}
  	
  	//删除表
  	public static void deleteTable(String tableName) {
  		TableName table = TableName.valueOf(tableName);
  		try {
  			admin = initHBase().getAdmin();
  			admin.disableTable(table);
  			admin.deleteTable(table);
  		} catch (IOException e) {
  			e.printStackTrace();
  		}
  		
  	}
  	
  	
  }
  

  • 启动hbase集群，参考hbase2.0.0集群

  • 启动java程序进行测试