代码样例

以下代码片段在com.huawei.bigdata.hbase.examples包的“HBaseExample”类的testModifyTable方法中。

public void testModifyTable() {     LOG .info("Entering testModifyTable.");    // Specify the column family name.    byte[] familyName = Bytes.toBytes("education");    Admin admin = null;    try {        // Instantiate an Admin object.        admin = conn.getAdmin();        // Obtain the table descriptor.        TableDescriptor htd = TableDescriptorBuilder.newBuilder(tableName).build();        // Check whether the column family is specified before modification.        if (!htd.hasColumnFamily(familyName)) {            // Create the column descriptor.         ColumnFamilyDescriptor cfd = ColumnFamilyDescriptorBuilder.of(familyName);         TableDescriptor td = TableDescriptorBuilder.newBuilder(admin.getDescriptor(tableName)).setColumnFamily(cfd).build();            // Disable the table to get the table offline before modifying            // the table.            admin.disableTable(tableName);//注[1]            // Submit a modifyTable request.            admin.modifyTable(td);            // Enable the table to get the table online after modifying the            // table.            admin.enableTable(tableName);        }        LOG.info("Modify table successfully.");    } catch (IOException e) {        LOG.error("Modify table failed ", e);    } finally {        if (admin != null) {            try {                // Close the Admin object.                admin.close();            } catch (IOException e) {                LOG.error("Close admin failed ", e);            }        }    }    LOG.info("Exiting testModifyTable.");}