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 io.prestosql.plugin.jmx; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import io.airlift.slice.Slice; import io.prestosql.spi.NodeManager; import io.prestosql.spi.connector.ColumnHandle; import io.prestosql.spi.connector.ConnectorRecordSetProvider; import io.prestosql.spi.connector.ConnectorSession; import io.prestosql.spi.connector.ConnectorSplit; import io.prestosql.spi.connector.ConnectorTransactionHandle; import io.prestosql.spi.connector.InMemoryRecordSet; import io.prestosql.spi.connector.RecordSet; import io.prestosql.spi.type.Type; import javax.inject.Inject; import javax.management.Attribute; import javax.management.JMException; import javax.management.MBeanServer; import javax.management.ObjectName; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Optional; import java.util.Set; import java.util.stream.Collectors; import static com.google.common.base.Preconditions.checkArgument; import static com.google.common.collect.ImmutableList.toImmutableList; import static java.util.Objects.requireNonNull; public class JmxRecordSetProvider implements ConnectorRecordSetProvider { private final MBeanServer mbeanServer; private final String nodeId; private final JmxHistoricalData jmxHistoricalData; @Inject public JmxRecordSetProvider(MBeanServer mbeanServer, NodeManager nodeManager, JmxHistoricalData jmxHistoricalData) { this.mbeanServer = requireNonNull(mbeanServer, "mbeanServer is null"); this.nodeId = requireNonNull(nodeManager, "nodeManager is null").getCurrentNode().getNodeIdentifier(); this.jmxHistoricalData = requireNonNull(jmxHistoricalData, "jmxHistoryHolder is null"); } public List<Object> getLiveRow(String objectName, List<? extends ColumnHandle> columns, long entryTimestamp) throws JMException { ImmutableMap<String, Optional<Object>> attributes = getAttributes(getColumnNames(columns), objectName); List<Object> row = new ArrayList<>(); for (ColumnHandle column : columns) { JmxColumnHandle jmxColumn = (JmxColumnHandle) column; if (jmxColumn.getColumnName().equals(JmxMetadata.NODE_COLUMN_NAME)) { row.add(nodeId); } else if (jmxColumn.getColumnName().equals(JmxMetadata.OBJECT_NAME_NAME)) { row.add(objectName); } else if (jmxColumn.getColumnName().equals(JmxMetadata.TIMESTAMP_COLUMN_NAME)) { row.add(entryTimestamp); } else { Optional<Object> optionalValue = attributes.get(jmxColumn.getColumnName()); if (optionalValue == null || !optionalValue.isPresent()) { row.add(null); } else { Object value = optionalValue.get(); Class<?> javaType = jmxColumn.getColumnType().getJavaType(); if (javaType == boolean.class) { if (value instanceof Boolean) { row.add(value); } else { // mbeans can lie about types row.add(null); } } else if (javaType == long.class) { if (value instanceof Number) { row.add(((Number) value).longValue()); } else { // mbeans can lie about types row.add(null); } } else if (javaType == double.class) { if (value instanceof Number) { row.add(((Number) value).doubleValue()); } else { // mbeans can lie about types row.add(null); } } else if (javaType == Slice.class) { if (value.getClass().isArray()) { // return a string representation of the array if (value.getClass().getComponentType() == boolean.class) { row.add(Arrays.toString((boolean[]) value)); } else if (value.getClass().getComponentType() == byte.class) { row.add(Arrays.toString((byte[]) value)); } else if (value.getClass().getComponentType() == char.class) { row.add(Arrays.toString((char[]) value)); } else if (value.getClass().getComponentType() == double.class) { row.add(Arrays.toString((double[]) value)); } else if (value.getClass().getComponentType() == float.class) { row.add(Arrays.toString((float[]) value)); } else if (value.getClass().getComponentType() == int.class) { row.add(Arrays.toString((int[]) value)); } else if (value.getClass().getComponentType() == long.class) { row.add(Arrays.toString((long[]) value)); } else if (value.getClass().getComponentType() == short.class) { row.add(Arrays.toString((short[]) value)); } else { row.add(Arrays.toString((Object[]) value)); } } else { row.add(value.toString()); } } } } } return row; } @Override public RecordSet getRecordSet(ConnectorTransactionHandle transaction, ConnectorSession session, ConnectorSplit split, List<? extends ColumnHandle> columns) { JmxTableHandle tableHandle = ((JmxSplit) split).getTableHandle(); requireNonNull(columns, "columns is null"); checkArgument(!columns.isEmpty(), "must provide at least one column"); List<List<Object>> rows; try { if (tableHandle.isLiveData()) { rows = getLiveRows(tableHandle, columns); } else { List<Integer> selectedColumns = calculateSelectedColumns(tableHandle.getColumnHandles(), getColumnNames(columns)); rows = tableHandle.getObjectNames().stream() .flatMap(objectName -> jmxHistoricalData.getRows(objectName, selectedColumns).stream()) .collect(toImmutableList()); } } catch (JMException e) { rows = ImmutableList.of(); } return new InMemoryRecordSet(getColumnTypes(columns), rows); } private List<Integer> calculateSelectedColumns(List<JmxColumnHandle> columnHandles, Set<String> selectedColumnNames) { ImmutableList.Builder<Integer> selectedColumns = ImmutableList.builder(); for (int i = 0; i < columnHandles.size(); i++) { JmxColumnHandle column = columnHandles.get(i); if (selectedColumnNames.contains((column.getColumnName()))) { selectedColumns.add(i); } } return selectedColumns.build(); } private static Set<String> getColumnNames(List<? extends ColumnHandle> columnHandles) { return columnHandles.stream().map(column -> (JmxColumnHandle) column).map(JmxColumnHandle::getColumnName) .collect(Collectors.toSet()); } private static List<Type> getColumnTypes(List<? extends ColumnHandle> columnHandles) { return columnHandles.stream().map(column -> (JmxColumnHandle) column).map(JmxColumnHandle::getColumnType) .collect(Collectors.toList()); } private ImmutableMap<String, Optional<Object>> getAttributes(Set<String> uniqueColumnNames, String name) throws JMException { ObjectName objectName = new ObjectName(name); String[] columnNamesArray = uniqueColumnNames.toArray(new String[uniqueColumnNames.size()]); ImmutableMap.Builder<String, Optional<Object>> attributes = ImmutableMap.builder(); for (Attribute attribute : mbeanServer.getAttributes(objectName, columnNamesArray).asList()) { attributes.put(attribute.getName(), Optional.ofNullable(attribute.getValue())); } return attributes.build(); } private List<List<Object>> getLiveRows(JmxTableHandle tableHandle, List<? extends ColumnHandle> columns) throws JMException { ImmutableList.Builder<List<Object>> rows = ImmutableList.builder(); for (String objectName : tableHandle.getObjectNames()) { rows.add(getLiveRow(objectName, columns, 0)); } return rows.build(); } }