HBase Java API 示例_hello_java_noob_go

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环境准备

在idea中创建Maven工程，导入HBase 客户端相关jar包，pom文件配置如下所示：

<repositories> <repository> <id>aliyun</id> <url>http://maven.aliyun.com/nexus/content/groups/public/</url> <releases><enabled>true</enabled></releases> <snapshots> <enabled>false</enabled> <updatePolicy>never</updatePolicy> </snapshots> </repository> </repositories> <dependencies> <dependency> <groupId>org.apache.hbase</groupId> <artifactId>hbase-client</artifactId> <version>2.1.0</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version></dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <dependency> <groupId>org.testng</groupId> <artifactId>testng</artifactId> <version>6.14.3</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.10</version> <scope>compile</scope> </dependency> </dependencies>

并在resouces下引入log4j.properties文件，可以在控制台清晰地看到日志信息：

log4j.rootLogger=INFO,stdout log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%5p - %m%n 常用类介绍 HBaseConfiguration 该类是用来创建HBase配置对象，常用的是静态create方法。该方法中返回了Hadoop Configuration 对象，同时加载了HBase中的资源文件。如下： Configuration conf = new Configuration(); conf.setClassLoader(HBaseConfiguration.class.getClassLoader()); return addHbaseResources(conf); 管理对象HBaseAdmin和HTable 两者都是从Connection对象中获取，其中HBaseAdmin对象用于管理表，包括表的创建，删除、禁用等； HTable对象主要用于操作表中数据，包括数据的添加、查询、修改、删除等操作TableDescriptor TableDescriptor 对象用于描述表，包括表名、表中列族等。ColumnFamilyDescriptor ColumnFamilyDescriptor 对象用于表述列族信息，包括列族名称、列族中各种属性Put、Get、Delete 这些对象用于封装对表中数据的操作，构造方法中传入rowkey信息，根据rowkey对一行数据进行操作，同时还可以添加Column信息，对特定列进行操作。Put用于添加和修改数据，Get用于查询数据，Delete用于删除数据。常见操作示例

封装创建链接和释放连接方法，创建连接时需要指定ZK集群的IP和端口信息，从而通过ZK集群找到HBase的元数据信息，建立连接：

public static Connection getConnection(String zkIPStr) throws IOException { Configuration conf = HBaseConfiguration.create(); conf.set("hbase.zookeeper.quorum", zkIPStr); return ConnectionFactory.createConnection(conf); } public static void closeConn(Connection conn, Admin admin, Table table) { if (table != null) { try { table.close(); } catch (IOException e) { throw new RuntimeException(e); } } if (admin != null) { try { admin.close(); } catch (IOException e) { throw new RuntimeException(e); } } if (conn != null) { try { conn.close(); } catch (IOException e) { throw new RuntimeException(e); } } } 创建表 @Test public void createTable() throws IOException { //创建连接 //获取管理对象 Admin admin = conn.getAdmin(); //进行操作 if (admin.tableExists(TableName.valueOf("WATER_BILL"))) { return; } TableDescriptor tableDesc = TableDescriptorBuilder.newBuilder(TableName.valueOf("WATER_BILL")) .setColumnFamily(ColumnFamilyDescriptorBuilder.newBuilder("C1".getBytes()).build()).build(); admin.createTable(tableDesc); //查询结果集 //释放连接 } 添加数据 @Test public void putData() throws IOException { table = conn.getTable(TableName.valueOf("WATER_BILL")); Put put = new Put("rk001".getBytes()); put.addColumn("f1".getBytes(), "name".getBytes(), "登卫红".getBytes()); put.addColumn("f1".getBytes(), "address".getBytes(), "贵州省铜仁市".getBytes()); put.addColumn("f1".getBytes(), "sex".getBytes(), "男".getBytes()); table.put(put); } 查询数据 @Test public void queryData() throws IOException { table = conn.getTable(TableName.valueOf("WATER_BILL")); Get get = new Get("rk001".getBytes()); Result result = table.get(get); List<Cell> cells = result.listCells(); if (cells != null) { for (Cell cell : cells) { String row = Bytes.toString(CellUtil.cloneRow(cell)); String family = Bytes.toString(CellUtil.cloneFamily(cell)); String columnName = Bytes.toString(CellUtil.cloneQualifier(cell)); String value = Bytes.toString(CellUtil.cloneValue(cell)); System.out.println("rowkey: " + row + ", family:column " + family + ":" + columnName + ", value: " + value ); } } else { System.out.println("No data"); } } 删除数据 @Test public void deleteData() throws IOException { table = conn.getTable(TableName.valueOf("WATER_BILL")); Delete delete = new Delete("rk001".getBytes()); table.delete(delete); } @Test public void deleteTable() throws IOException { admin = conn.getAdmin(); if (admin.isTableEnabled(TableName.valueOf("WATER_BILL"))) { admin.disableTable(TableName.valueOf("WATER_BILL")); } admin.deleteTable(TableName.valueOf("WATER_BILL")); } 基于Scan的扫描查询 @Test public void scanTable() throws IOException { Scan scan = new Scan(); table = conn.getTable(TableName.valueOf("WATER_BILL")); BinaryComparator startTimeComp = new BinaryComparator("2020-06-01".getBytes()); BinaryComparator endTimeComp = new BinaryComparator("2020-06-30".getBytes()); SingleColumnValueFilter startTimeFilter = new SingleColumnValueFilter("C1".getBytes(), "RECORD_DATE".getBytes(), CompareOperator.GREATER_OR_EQUAL, startTimeComp); SingleColumnValueFilter endTimeFilter = new SingleColumnValueFilter("C1".getBytes(), "RECORD_DATE".getBytes(), CompareOperator.LESS_OR_EQUAL, endTimeComp); FilterList filterList = new FilterList(); filterList.addFilter(startTimeFilter); filterList.addFilter(endTimeFilter); scan.setFilter(filterList); scan.addColumn("C1".getBytes(), "RECORD_DATE".getBytes()); scan.addColumn("C1".getBytes(), "NAME".getBytes()); scan.addColumn("C1".getBytes(), "NUM_USAGE".getBytes()); ResultScanner scanner = table.getScanner(scan); Iterator<Result> iterator = scanner.iterator(); while (iterator.hasNext()) { Result next = iterator.next(); List<Cell> cells = next.listCells(); if (cells != null) { for (Cell cell : cells) { String row = Bytes.toString(CellUtil.cloneRow(cell)); String family = Bytes.toString(CellUtil.cloneFamily(cell)); String columnName = Bytes.toString(CellUtil.cloneQualifier(cell)); Object value; if ("NUM_USAGE".equals(columnName)) { value = Bytes.toDouble(CellUtil.cloneValue(cell)); } else { value = Bytes.toString(CellUtil.cloneValue(cell)); } System.out.println("rowkey: " + row + ", family:column " + family + ":" + columnName + ", value: " + value ); } } else { System.out.println("No data"); } } }