Mavenを用いたKuduクライアントの導入

<dependency>
  <groupId>org.apache.kudu</groupId>
  <artifactId>kudu-client</artifactId>
  <version>1.6.0</version>
</dependency>

テーブル作成の実装

public class KuduTableCreator {
    private static ColumnSchema buildColumn(String colName, Type dataType, boolean primaryKey) {
        return new ColumnSchema.ColumnSchemaBuilder(colName, dataType)
                .key(primaryKey)
                .build();
    }

    public static void main(String[] args) {
        final String masterNodes = "master-node1,master-node2";
        try (KuduClient client = new KuduClient.KuduClientBuilder(masterNodes).build()) {
            
            List<ColumnSchema> schemaColumns = Arrays.asList(
                buildColumn("OrgID", Type.INT32, true),
                buildColumn("EmployeeID", Type.INT32, false),
                buildColumn("FullName", Type.STRING, false)
            );
            
            CreateTableOptions tableConfig = new CreateTableOptions()
                .setNumReplicas(2)
                .setRangePartitionColumns(List.of("OrgID"))
                .addHashPartitions(List.of("OrgID"), 4);
                
            client.createTable("EmployeeData", new Schema(schemaColumns), tableConfig);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

テーブル削除処理

public class TableRemover {
    public static void main(String[] args) {
        try (KuduClient client = new KuduClient.KuduClientBuilder("master-nodes").build()) {
            client.deleteTable("EmployeeData");
        } catch (KuduException e) {
            e.printStackTrace();
        }
    }
}

データ登録方法

public class DataInserter {
    public static void main(String[] args) {
        try (KuduClient client = new KuduClient.KuduClientBuilder("cluster-masters").build();
             KuduSession session = client.newSession()) {
             
            KuduTable table = client.openTable("EmployeeData");
            session.setFlushMode(FlushMode.AUTO_FLUSH_BACKGROUND);
            
            for (int i = 1; i <= 50; i++) {
                Insert record = table.newInsert();
                record.getRow()
                    .addInt("OrgID", i)
                    .addInt("EmployeeID", 1000 + i)
                    .addString("FullName", "Employee_" + i);
                session.apply(record);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

データ検索処理

public class DataQuery {
    public static void main(String[] args) {
        try (KuduClient client = new KuduClient.KuduClientBuilder("kudu-masters").build()) {
            KuduTable table = client.openTable("EmployeeData");
            KuduScanner scanner = client.newScannerBuilder(table)
                .addPredicate(
                    KuduPredicate.newComparisonPredicate(
                        table.getSchema().getColumn("OrgID"),
                        KuduPredicate.ComparisonOp.EQUAL,
                        5
                    )
                )
                .build();
                
            for (RowResult row : scanner) {
                System.out.printf(
                    "ID:%d, Name:%s%n",
                    row.getInt("EmployeeID"),
                    row.getString("FullName")
                );
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

データ更新手法

public class DataUpdater {
    public static void main(String[] args) {
        try (KuduClient client = new KuduClient.KuduClientBuilder("master-hosts").build();
             KuduSession session = client.newSession()) {
             
            KuduTable table = client.openTable("EmployeeData");
            Update modification = table.newUpdate();
            modification.getRow()
                .addInt("OrgID", 3)
                .addString("FullName", "Updated_Name");
                
            session.apply(modification);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

行削除の実装

public class RowDeleter {
    public static void main(String[] args) {
        try (KuduClient client = new KuduClient.KuduClientBuilder("master-servers").build();
             KuduSession session = client.newSession()) {
             
            KuduTable table = client.openTable("EmployeeData");
            Delete removal = table.newDelete();
            removal.getRow().addInt("OrgID", 7);
            session.apply(removal);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}