云服务器内容精选

  • 代码样例 以下代码片段在com.huawei.bigdata.hbase.examples包的“HBaseSample”类的testDelete方法中。 public void testDelete() { LOG .info("Entering testDelete."); byte[] rowKey = Bytes.toBytes("012005000201"); Table table = null; try { // Instantiate an HTable object. table = conn.getTable(tableName); // Instantiate an Delete object. Delete delete = new Delete(rowKey); // Submit a delete request. table.delete(delete); LOG.info("Delete table successfully."); } catch (IOException e) { LOG.error("Delete table failed " ,e); } finally { if (table != null) { try { // Close the HTable object. table.close(); } catch (IOException e) { LOG.error("Close table failed " ,e); } } } LOG.info("Exiting testDelete."); } 如果被删除的cell所在的列族上设置了二级索引,也会同步删除索引数据。
  • 代码样例 hbase.root.logger=INFO,console,RFA //hbase客户端日志输出配置,console:输出到控制台;RFA:输出到日志文件 hbase.security.logger=DEBUG,console,RFAS //hbase客户端安全相关的日志输出配置,console:输出到控制台;RFAS:输出到日志文件 hbase.log.dir=/var/log/Bigdata/hbase/client/ //日志路径,根据实际路径修改,但目录要有写入权限 hbase.log.file=hbase-client.log //日志文件名 hbase.log.level=INFO //日志级别,如果需要更详细的日志定位问题,需要修改为DEBUG,修改完需要重启进程才能生效 hbase.log.maxbackupindex=20 //最多保存的日志文件数目 # Security audit appender hbase.security.log.file=hbase-client-audit.log //审计日志文件命令
  • 代码样例 hbase.root.logger=INFO,console,RFA //hbase客户端日志输出配置,console:输出到控制台;RFA:输出到日志文件 hbase.security.logger=DEBUG,console,RFAS //hbase客户端安全相关的日志输出配置,console:输出到控制台;RFAS:输出到日志文件 hbase.log.dir=/var/log/Bigdata/hbase/client/ //日志路径,根据实际路径修改,但目录要有写入权限 hbase.log.file=hbase-client.log //日志文件名 hbase.log.level=INFO //日志级别,如果需要更详细的日志定位问题,需要修改为DEBUG,修改完需要重启进程才能生效 hbase.log.maxbackupindex=20 //最多保存的日志文件数目 # Security audit appender hbase.security.log.file=hbase-client-audit.log //审计日志文件命令
  • 代码样例 以下代码片段在com.huawei.bigdata.hbase.examples包的“PhoenixSample”类的testPut方法中。 /** * Put data */ public void testPut() { LOG.info("Entering testPut."); String URL = "jdbc:phoenix:" + conf.get("hbase.zookeeper.quorum"); // Insert String upsertSQL = "UPSERT INTO TEST VALUES(1,'John','100000', TO_DATE('1980-01-01','yyyy-MM-dd'))"; try (Connection conn = DriverManager.getConnection(url, props); Statement stat = conn.createStatement()){ // Execute Update SQL stat.executeUpdate(upsertSQL); conn.commit(); LOG.info("Put successfully."); } catch (Exception e) { LOG.error("Put failed.", e); } LOG.info("Exiting testPut."); }
  • 代码样例 以下代码片段在com.huawei.bigdata.hbase.examples包的“HBaseSample”类的testGet方法中。 public void testGet() { LOG.info("Entering testGet."); // Specify the column family name. byte[] familyName = Bytes.toBytes("info"); // Specify the column name. byte[][] qualifier = { Bytes.toBytes("name"), Bytes.toBytes("address") }; // Specify RowKey. byte[] rowKey = Bytes.toBytes("012005000201"); Table table = null; try { // Create the Table instance. table = conn.getTable(tableName); // Instantiate a Get object. Get get = new Get(rowKey); // Set the column family name and column name. get.addColumn(familyName, qualifier[0]); get.addColumn(familyName, qualifier[1]); // Submit a get request. Result result = table.get(get); // Print query results. for (Cell cell : result.rawCells()) { LOG.info("{}:{},{},{}", Bytes.toString(CellUtil.cloneRow(cell)), Bytes.toString(CellUtil.cloneFamily(cell)), Bytes.toString(CellUtil.cloneQualifier(cell)), Bytes.toString(CellUtil.cloneValue(cell))); } LOG.info("Get data successfully."); } catch (IOException e) { LOG.error("Get data failed " ,e); } finally { if (table != null) { try { // Close the HTable object. table.close(); } catch (IOException e) { LOG.error("Close table failed " ,e); } } } LOG.info("Exiting testGet."); }
  • 功能介绍 HBase通过ConnectionFactory.createConnection(configuration)方法创建Connection对象。传递的参数为上一步创建的Configuration。 Connection封装了底层与各实际服务器的连接以及与ZooKeeper的连接。Connection通过ConnectionFactory类实例化。创建Connection是重量级操作,Connection是线程安全的,因此,多个客户端线程可以共享一个Connection。 典型的用法,一个客户端程序共享一个单独的Connection,每一个线程获取自己的Admin或Table实例,然后调用Admin对象或Table对象提供的操作接口。不建议缓存或者池化Table、Admin。Connection的生命周期由调用者维护,调用者通过调用close(),释放资源。
  • 代码样例 以下代码片段是登录,创建Connection并创建表的示例,在com.huawei.bigdata.hbase.examples包的“HBaseSample”类的HBaseSample方法中。 private TableName tableName = null; private Connection conn = null; public HBaseSample(Configuration conf) throws IOException { this.tableName = TableName.valueOf("hbase_sample_table"); this.conn = ConnectionFactory.createConnection(conf); }
  • 代码样例 以下代码片段在com.huawei.bigdata.hbase.examples包的“PhoenixSample”类的testSelect方法中。 /** * Select Data */ public void testSelect() { LOG.info("Entering testSelect."); String URL = "jdbc:phoenix:" + conf.get("hbase.zookeeper.quorum"); // Query String querySQL = "SELECT * FROM TEST WHERE id = ?"; Connection conn = null; PreparedStatement preStat = null; Statement stat = null; ResultSet result = null; try { // Create Connection conn = DriverManager.getConnection(url, props); // Create Statement stat = conn.createStatement(); // Create PrepareStatement preStat = conn.prepareStatement(querySQL); // Execute query preStat.setInt(1, 1); result = preStat.executeQuery(); // Get result while (result.next()) { int id = result.getInt("id"); String name = result.getString(1); System.out.println("id: " + id); System.out.println("name: " + name); } LOG.info("Select successfully."); } catch (Exception e) { LOG.error("Select failed.", e); } finally { if (null != result) { try { result.close(); } catch (Exception e2) { LOG.error("Result close failed.", e2); } } if (null != stat) { try { stat.close(); } catch (Exception e2) { LOG.error("Stat close failed.", e2); } } if (null != conn) { try { conn.close(); } catch (Exception e2) { LOG.error("Connection close failed.", e2); } } } LOG.info("Exiting testSelect."); }
  • 注意事项 当前二级索引不支持使用SubstringComparator类定义的对象作为Filter的比较器。 例如,如下示例中的用法当前不支持: Scan scan = new Scan(); filterList = new FilterList(FilterList.Operator.MUST_PASS_ALL); filterList.addFilter(new SingleColumnValueFilter(Bytes .toBytes(columnFamily), Bytes.toBytes(qualifier), CompareOperator.EQUAL, new SubstringComparator(substring))); scan.setFilter(filterList);
  • 代码样例 以下代码片段在com.huawei.bigdata.hbase.examples包的“HBaseSample”类的testSingleColumnValueFilter方法中。 public void testSingleColumnValueFilter() { LOG.info("Entering testSingleColumnValueFilter."); Table table = null; ResultScanner rScanner = null; try { table = conn.getTable(tableName); Scan scan = new Scan(); scan.addColumn(Bytes.toBytes("info"), Bytes.toBytes("name")); // Set the filter criteria. SingleColumnValueFilter filter = new SingleColumnValueFilter( Bytes.toBytes("info"), Bytes.toBytes("name"), CompareOperator.EQUAL, Bytes.toBytes("Xu Bing")); scan.setFilter(filter); // Submit a scan request. rScanner = table.getScanner(scan); // Print query results. for (Result r = rScanner.next(); r != null; r = rScanner.next()) { for (Cell cell : r.rawCells()) { LOG.info("{}:{},{},{}", Bytes.toString(CellUtil.cloneRow(cell)), Bytes.toString(CellUtil.cloneFamily(cell)), Bytes.toString(CellUtil.cloneQualifier(cell)), Bytes.toString(CellUtil.cloneValue(cell))); } } LOG.info("Single column value filter successfully."); } catch (IOException e) { LOG.error("Single column value filter failed " ,e); } finally { if (rScanner != null) { // Close the scanner object. rScanner.close(); } if (table != null) { try { // Close the HTable object. table.close(); } catch (IOException e) { LOG.error("Close table failed " ,e); } } } LOG.info("Exiting testSingleColumnValueFilter."); }
  • 代码样例 以下代码片段在com.huawei.bigdata.hbase.examples包的“PhoenixSample”类的testCreateTable方法中。 /** * Create Table */ public void testCreateTable() { LOG.info("Entering testCreateTable."); String URL = "jdbc:phoenix:" + conf.get("hbase.zookeeper.quorum"); // Create table String createTableSQL = "CREATE TABLE IF NOT EXISTS TEST (id integer not null primary key, name varchar, " + "account char(6), birth date)"; try (Connection conn = DriverManager.getConnection(url, props); Statement stat = conn.createStatement()) { // Execute Create SQL stat.executeUpdate(createTableSQL); LOG.info("Create table successfully."); } catch (Exception e) { LOG.error("Create table failed.", e); } LOG.info("Exiting testCreateTable."); } /** * Drop Table */ public void testDrop() { LOG.info("Entering testDrop."); String URL = "jdbc:phoenix:" + conf.get("hbase.zookeeper.quorum"); // Delete table String dropTableSQL = "DROP TABLE TEST"; try (Connection conn = DriverManager.getConnection(url, props); Statement stat = conn.createStatement()) { stat.executeUpdate(dropTableSQL); LOG.info("Drop successfully."); } catch (Exception e) { LOG.error("Drop failed.", e); } LOG.info("Exiting testDrop."); }
  • 代码样例 以下代码片段在com.huawei.bigdata.hbase.examples包的“HBaseSample”类的testScanData方法中。 public void testScanData() { LOG.info("Entering testScanData."); Table table = null; // Instantiate a ResultScanner object. ResultScanner rScanner = null; try { // Create the Configuration instance. table = conn.getTable(tableName); // Instantiate a Get object. Scan scan = new Scan(); scan.addColumn(Bytes.toBytes("info"), Bytes.toBytes("name")); // Set the cache size. scan.setCaching(1000); // Submit a scan request. rScanner = table.getScanner(scan); // Print query results. for (Result r = rScanner.next(); r != null; r = rScanner.next()) { for (Cell cell : r.rawCells()) { LOG.info("{}:{},{},{}", Bytes.toString(CellUtil.cloneRow(cell)), Bytes.toString(CellUtil.cloneFamily(cell)), Bytes.toString(CellUtil.cloneQualifier(cell)), Bytes.toString(CellUtil.cloneValue(cell))); } } LOG.info("Scan data successfully."); } catch (IOException e) { LOG.error("Scan data failed " ,e); } finally { if (rScanner != null) { // Close the scanner object. rScanner.close(); } if (table != null) { try { // Close the HTable object. table.close(); } catch (IOException e) { LOG.error("Close table failed " ,e); } } } LOG.info("Exiting testScanData."); }
  • 注意事项 注[1]:创建联合索引 HBase支持在多个字段上创建二级索引,例如在列name和age上。 HIndexSpecification iSpecUnite = new HIndexSpecification(indexName); iSpecUnite.addIndexColumn(new HColumnDescriptor("info"), "name", ValueType.String); iSpecUnite.addIndexColumn(new HColumnDescriptor("info"), "age", ValueType.String);