Java tutorial
/* * 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.facebook.presto.connector.jmx; import com.facebook.presto.spi.ColumnHandle; import com.facebook.presto.spi.ColumnMetadata; import com.facebook.presto.spi.ConnectorMetadata; import com.facebook.presto.spi.ConnectorSession; import com.facebook.presto.spi.ConnectorTableHandle; import com.facebook.presto.spi.ConnectorTableMetadata; import com.facebook.presto.spi.SchemaTableName; import com.facebook.presto.spi.SchemaTablePrefix; import com.facebook.presto.spi.type.Type; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableList.Builder; import com.google.common.collect.ImmutableMap; import com.google.common.collect.Maps; import javax.management.JMException; import javax.management.MBeanAttributeInfo; import javax.management.MBeanInfo; import javax.management.MBeanServer; import javax.management.ObjectName; import java.util.List; import java.util.Map; import java.util.Optional; import static com.facebook.presto.connector.jmx.Types.checkType; import static com.facebook.presto.spi.type.BigintType.BIGINT; import static com.facebook.presto.spi.type.BooleanType.BOOLEAN; import static com.facebook.presto.spi.type.DoubleType.DOUBLE; import static com.facebook.presto.spi.type.VarcharType.VARCHAR; import static java.util.Locale.ENGLISH; import static java.util.Objects.requireNonNull; import static javax.management.ObjectName.WILDCARD; public class JmxMetadata implements ConnectorMetadata { public static final String SCHEMA_NAME = "jmx"; private final String connectorId; private final MBeanServer mbeanServer; public JmxMetadata(String connectorId, MBeanServer mbeanServer) { this.connectorId = requireNonNull(connectorId, "connectorId is null"); this.mbeanServer = requireNonNull(mbeanServer, "mbeanServer is null"); } @Override public List<String> listSchemaNames(ConnectorSession session) { return ImmutableList.of(SCHEMA_NAME); } @Override public JmxTableHandle getTableHandle(ConnectorSession session, SchemaTableName tableName) { requireNonNull(tableName, "tableName is null"); if (!tableName.getSchemaName().equals(SCHEMA_NAME)) { return null; } try { String canonicalName = new ObjectName(tableName.getTableName()).getCanonicalName(); Optional<ObjectName> objectName = mbeanServer.queryNames(WILDCARD, null).stream() .filter(name -> canonicalName.equalsIgnoreCase(name.getCanonicalName())).findFirst(); if (!objectName.isPresent()) { return null; } MBeanInfo mbeanInfo = mbeanServer.getMBeanInfo(objectName.get()); ImmutableList.Builder<JmxColumnHandle> columns = ImmutableList.builder(); columns.add(new JmxColumnHandle(connectorId, "node", VARCHAR)); for (MBeanAttributeInfo attribute : mbeanInfo.getAttributes()) { if (!attribute.isReadable()) { continue; } columns.add(new JmxColumnHandle(connectorId, attribute.getName(), getColumnType(attribute))); } return new JmxTableHandle(connectorId, objectName.get().toString(), columns.build()); } catch (JMException e) { return null; } } @Override public ConnectorTableMetadata getTableMetadata(ConnectorSession session, ConnectorTableHandle tableHandle) { return checkType(tableHandle, JmxTableHandle.class, "tableHandle").getTableMetadata(); } @Override public List<SchemaTableName> listTables(ConnectorSession session, String schemaNameOrNull) { if (schemaNameOrNull != null && !schemaNameOrNull.equals(SCHEMA_NAME)) { return ImmutableList.of(); } Builder<SchemaTableName> tableNames = ImmutableList.builder(); for (ObjectName objectName : mbeanServer.queryNames(WILDCARD, null)) { // todo remove lower case when presto supports mixed case names tableNames.add(new SchemaTableName(SCHEMA_NAME, objectName.toString().toLowerCase(ENGLISH))); } return tableNames.build(); } @Override public Map<String, ColumnHandle> getColumnHandles(ConnectorSession session, ConnectorTableHandle tableHandle) { JmxTableHandle jmxTableHandle = checkType(tableHandle, JmxTableHandle.class, "tableHandle"); return ImmutableMap.copyOf(Maps.uniqueIndex(jmxTableHandle.getColumns(), column -> column.getColumnName().toLowerCase(ENGLISH))); } @Override public ColumnMetadata getColumnMetadata(ConnectorSession session, ConnectorTableHandle tableHandle, ColumnHandle columnHandle) { checkType(tableHandle, JmxTableHandle.class, "tableHandle"); return checkType(columnHandle, JmxColumnHandle.class, "columnHandle").getColumnMetadata(); } @Override public Map<SchemaTableName, List<ColumnMetadata>> listTableColumns(ConnectorSession session, SchemaTablePrefix prefix) { requireNonNull(prefix, "prefix is null"); if (prefix.getSchemaName() != null && !prefix.getSchemaName().equals(SCHEMA_NAME)) { return ImmutableMap.of(); } ImmutableMap.Builder<SchemaTableName, List<ColumnMetadata>> columns = ImmutableMap.builder(); List<SchemaTableName> tableNames; if (prefix.getTableName() == null) { tableNames = listTables(session, prefix.getSchemaName()); } else { tableNames = ImmutableList.of(new SchemaTableName(prefix.getSchemaName(), prefix.getTableName())); } for (SchemaTableName tableName : tableNames) { JmxTableHandle tableHandle = getTableHandle(session, tableName); columns.put(tableName, tableHandle.getTableMetadata().getColumns()); } return columns.build(); } private static Type getColumnType(MBeanAttributeInfo attribute) { switch (attribute.getType()) { case "boolean": case "java.lang.Boolean": return BOOLEAN; case "byte": case "java.lang.Byte": case "short": case "java.lang.Short": case "int": case "java.lang.Integer": case "long": case "java.lang.Long": return BIGINT; case "java.lang.Number": case "float": case "java.lang.Float": case "double": case "java.lang.Double": return DOUBLE; } return VARCHAR; } }