Java tutorial
/* Copyright 2015, Strategic Gains, Inc. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package com.orangerhymelabs.helenus.cassandra.table; import java.util.Date; import java.util.concurrent.ExecutionException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.datastax.driver.core.BoundStatement; import com.datastax.driver.core.PreparedStatement; import com.datastax.driver.core.ResultSetFuture; import com.datastax.driver.core.Row; import com.datastax.driver.core.Session; import com.google.common.util.concurrent.Futures; import com.google.common.util.concurrent.ListenableFuture; import com.orangerhymelabs.helenus.cassandra.AbstractCassandraRepository; import com.orangerhymelabs.helenus.cassandra.SchemaProvider; import com.orangerhymelabs.helenus.cassandra.document.DocumentRepository; import com.orangerhymelabs.helenus.cassandra.table.TableRepository.TableStatements; import com.orangerhymelabs.helenus.cassandra.table.key.KeyDefinitionException; import com.orangerhymelabs.helenus.cassandra.table.key.KeyDefinitionParser; import com.orangerhymelabs.helenus.exception.StorageException; import com.orangerhymelabs.helenus.persistence.Identifier; import com.orangerhymelabs.helenus.persistence.Query; import com.orangerhymelabs.helenus.persistence.StatementFactory; /** * @author tfredrich * @since Jun 8, 2015 */ public class TableRepository extends AbstractCassandraRepository<Table, TableStatements> { private static final Logger LOG = LoggerFactory.getLogger(TableRepository.class); private static final KeyDefinitionParser KEY_PARSER = new KeyDefinitionParser(); private class Tables { static final String BY_ID = "sys_tbl"; } private class Columns { static final String NAME = "tbl_name"; static final String DATABASE = "db_name"; static final String DESCRIPTION = "description"; static final String TYPE = "tbl_type"; static final String KEYS = "keys"; static final String TTL = "tbl_ttl"; static final String VIEWS = "views"; static final String CREATED_AT = "created_at"; static final String UPDATED_AT = "updated_at"; } public static class Schema implements SchemaProvider { private static final String DROP_TABLE = "drop table if exists %s." + Tables.BY_ID; private static final String CREATE_TABLE = "create table %s." + Tables.BY_ID + "(" + Columns.DATABASE + " text," + Columns.NAME + " text," + Columns.DESCRIPTION + " text," + Columns.TYPE + " text," + Columns.KEYS + " text," + Columns.TTL + " bigint," + Columns.VIEWS + " list<text>," + Columns.CREATED_AT + " timestamp," + Columns.UPDATED_AT + " timestamp," + "primary key ((" + Columns.DATABASE + "), " + Columns.NAME + ")" + ")"; @Override public boolean drop(Session session, String keyspace) { ResultSetFuture rs = session.executeAsync(String.format(DROP_TABLE, keyspace)); try { return rs.get().wasApplied(); } catch (InterruptedException | ExecutionException e) { LOG.error("Table schema drop failed", e); } return false; } @Override public boolean create(Session session, String keyspace) { ResultSetFuture rs = session.executeAsync(String.format(CREATE_TABLE, keyspace)); try { return rs.get().wasApplied(); } catch (InterruptedException | ExecutionException e) { LOG.error("Table schema create failed", e); } return false; } } private static final String IDENTITY_CQL = " where " + Columns.DATABASE + " = ? and " + Columns.NAME + " = ?"; public interface TableStatements extends StatementFactory { @Override @Query("insert into %s." + Tables.BY_ID + " (" + Columns.NAME + ", " + Columns.DATABASE + ", " + Columns.DESCRIPTION + ", " + Columns.TYPE + ", " + Columns.KEYS + ", " + Columns.TTL + ", " + Columns.CREATED_AT + ", " + Columns.UPDATED_AT + ") values (?, ?, ?, ?, ?, ?, ?, ?) if not exists") PreparedStatement create(); @Override @Query("delete from %s." + Tables.BY_ID + IDENTITY_CQL) PreparedStatement delete(); @Override @Query("update %s." + Tables.BY_ID + " set " + Columns.DESCRIPTION + " = ?, " + Columns.TTL + " = ?, " + Columns.UPDATED_AT + " = ?" + IDENTITY_CQL + " if exists") PreparedStatement update(); @Override @Query("select * from %s." + Tables.BY_ID + IDENTITY_CQL) PreparedStatement read(); @Override @Query("select count(*) from %s." + Tables.BY_ID + IDENTITY_CQL + " limit 1") PreparedStatement exists(); @Override @Query("select * from %s." + Tables.BY_ID + " where " + Columns.DATABASE + " = ?") PreparedStatement readAll(); } private static final DocumentRepository.Schema DOCUMENT_SCHEMA = new DocumentRepository.Schema(); public TableRepository(Session session, String keyspace) { super(session, keyspace, TableStatements.class); } @Override public ListenableFuture<Table> create(Table table) { if (createDocumentSchema(table)) { // TODO: what about rollback? return super.create(table); } else { return Futures.immediateFailedFuture( new StorageException("Failed to create document schema for: " + table.toDbTable())); } } @Override public ListenableFuture<Boolean> delete(Identifier id) { if (dropDocumentSchema(id)) { // TODO: what about rollback? return super.delete(id); } else { return Futures.immediateFailedFuture( new StorageException("Failed to drop document schema for: " + id.toDbName())); } } @Override protected void bindCreate(BoundStatement bs, Table table) { Date now = new Date(); table.createdAt(now); table.updatedAt(now); bs.bind(table.name(), table.database().name(), table.description(), table.type().name(), table.keys(), table.ttl(), table.createdAt(), table.updatedAt()); } @Override protected void bindUpdate(BoundStatement bs, Table table) { table.updatedAt(new Date()); bs.bind(table.description(), table.ttl(), table.updatedAt(), table.database().name(), table.name()); } protected Table marshalRow(Row row) { if (row == null) return null; Table table = new Table(); table.name(row.getString(Columns.NAME)); table.database(row.getString(Columns.DATABASE)); table.description(row.getString(Columns.DESCRIPTION)); table.ttl(row.getLong(Columns.TTL)); table.type(TableType.from(row.getString(Columns.TYPE))); table.keys(row.getString(Columns.KEYS)); table.createdAt(row.getTimestamp(Columns.CREATED_AT)); table.updatedAt(row.getTimestamp(Columns.UPDATED_AT)); return table; } private boolean createDocumentSchema(Table table) { try { return DOCUMENT_SCHEMA.create(session(), keyspace(), table.toDbTable(), KEY_PARSER.parse(table.keys())); } catch (KeyDefinitionException e) { throw new StorageException(e); } } private boolean dropDocumentSchema(Identifier id) { return DOCUMENT_SCHEMA.drop(session(), keyspace(), id.toDbName()); } }