Apache HBase APIs · HBase? 中文參考指南 3.0

# Apache HBase APIs > 貢獻者：[xixici](https://github.com/xixici) 本章節提供有關使用基礎 HBase API 執行操作的方法。此方法并非詳盡無遺，快速參考 [User API Reference](https://hbase.apache.org/apidocs/index.html)。此處的示例不全面，僅用于說明目的。 Apache HBase 也擁有多種外部 APIs. 詳見:[Apache HBase External APIs](#external_apis) ## 96\. 例子 Example 25\. 使用 Java 創建.修改和刪除表 ``` package com.example.hbase.admin; import java.io.IOException; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.HColumnDescriptor; import org.apache.hadoop.hbase.HConstants; 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.io.compress.Compression.Algorithm; public class Example { private static final String TABLE_NAME = "MY_TABLE_NAME_TOO"; private static final String CF_DEFAULT = "DEFAULT_COLUMN_FAMILY"; public static void createOrOverwrite(Admin admin, HTableDescriptor table) throws IOException { if (admin.tableExists(table.getTableName())) { admin.disableTable(table.getTableName()); admin.deleteTable(table.getTableName()); } admin.createTable(table); } public static void createSchemaTables(Configuration config) throws IOException { try (Connection connection = ConnectionFactory.createConnection(config); Admin admin = connection.getAdmin()) { HTableDescriptor table = new HTableDescriptor(TableName.valueOf(TABLE_NAME)); table.addFamily(new HColumnDescriptor(CF_DEFAULT).setCompressionType(Algorithm.NONE)); System.out.print("Creating table. "); createOrOverwrite(admin, table); System.out.println(" Done."); } } public static void modifySchema (Configuration config) throws IOException { try (Connection connection = ConnectionFactory.createConnection(config); Admin admin = connection.getAdmin()) { TableName tableName = TableName.valueOf(TABLE_NAME); if (!admin.tableExists(tableName)) { System.out.println("Table does not exist."); System.exit(-1); } HTableDescriptor table = admin.getTableDescriptor(tableName); // 更新表格 HColumnDescriptor newColumn = new HColumnDescriptor("NEWCF"); newColumn.setCompactionCompressionType(Algorithm.GZ); newColumn.setMaxVersions(HConstants.ALL_VERSIONS); admin.addColumn(tableName, newColumn); // 更新列族 HColumnDescriptor existingColumn = new HColumnDescriptor(CF_DEFAULT); existingColumn.setCompactionCompressionType(Algorithm.GZ); existingColumn.setMaxVersions(HConstants.ALL_VERSIONS); table.modifyFamily(existingColumn); admin.modifyTable(tableName, table); // 禁用表格 admin.disableTable(tableName); // 刪除列族 admin.deleteColumn(tableName, CF_DEFAULT.getBytes("UTF-8")); // 刪除表格(需提前禁用) admin.deleteTable(tableName); } } public static void main(String... args) throws IOException { Configuration config = HBaseConfiguration.create(); //添加必要配置文件(hbase-site.xml, core-site.xml) config.addResource(new Path(System.getenv("HBASE_CONF_DIR"), "hbase-site.xml")); config.addResource(new Path(System.getenv("HADOOP_CONF_DIR"), "core-site.xml")); createSchemaTables(config); modifySchema(config); } } ```