Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more contributor license * agreements. See the NOTICE file distributed with this work for additional information regarding * copyright ownership. The ASF licenses this file to you 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 org.apache.zeppelin.impala; /* * This source file is based on code taken from SQLLine 1.0.2 See SQLLine notice in LICENSE */ import com.google.common.base.Joiner; import com.google.common.collect.Sets; import com.google.common.collect.Sets.SetView; import jline.console.completer.ArgumentCompleter.ArgumentList; import jline.console.completer.ArgumentCompleter.WhitespaceArgumentDelimiter; import jline.console.completer.StringsCompleter; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.sql.Connection; import java.sql.DatabaseMetaData; import java.sql.ResultSet; import java.sql.SQLException; import java.util.*; import java.util.regex.Pattern; import static org.apache.commons.lang.StringUtils.isBlank; /** * SQL auto complete functionality for the JdbcInterpreter. */ public class SqlCompleter extends StringsCompleter { private static Logger logger = LoggerFactory.getLogger(SqlCompleter.class); /** * Delimiter that can split SQL statement in keyword list */ private WhitespaceArgumentDelimiter sqlDelimiter = new WhitespaceArgumentDelimiter() { private Pattern pattern = Pattern.compile("[\\.:;,]"); @Override public boolean isDelimiterChar(CharSequence buffer, int pos) { return pattern.matcher("" + buffer.charAt(pos)).matches() || super.isDelimiterChar(buffer, pos); } }; private Set<String> modelCompletions = new HashSet<>(); public SqlCompleter(Set<String> allCompletions, Set<String> dataModelCompletions) { super(allCompletions); this.modelCompletions = dataModelCompletions; } @Override public int complete(String buffer, int cursor, List<CharSequence> candidates) { if (isBlank(buffer) || (cursor > buffer.length() + 1)) { return -1; } // The delimiter breaks the buffer into separate words (arguments), separated by the // white spaces. ArgumentList argumentList = sqlDelimiter.delimit(buffer, cursor); String argument = argumentList.getCursorArgument(); // cursor in the selected argument int argumentPosition = argumentList.getArgumentPosition(); if (isBlank(argument)) { int argumentsCount = argumentList.getArguments().length; if (argumentsCount <= 0 || ((buffer.length() + 2) < cursor) || sqlDelimiter.isDelimiterChar(buffer, cursor - 2)) { return -1; } argument = argumentList.getArguments()[argumentsCount - 1]; argumentPosition = argument.length(); } int complete = super.complete(argument, argumentPosition, candidates); logger.debug("complete:" + complete + ", size:" + candidates.size()); return complete; } public void updateDataModelMetaData(Connection connection) { try { Set<String> newModelCompletions = getDataModelMetadataCompletions(connection); logger.debug("New model metadata is:" + Joiner.on(',').join(newModelCompletions)); // Sets.difference(set1, set2) - returned set contains all elements that are contained by set1 // and not contained by set2. set2 may also contain elements not present in set1; these are // simply ignored. SetView<String> removedCompletions = Sets.difference(modelCompletions, newModelCompletions); logger.debug("Removed Model Completions: " + Joiner.on(',').join(removedCompletions)); this.getStrings().removeAll(removedCompletions); SetView<String> newCompletions = Sets.difference(newModelCompletions, modelCompletions); logger.debug("New Completions: " + Joiner.on(',').join(newCompletions)); this.getStrings().addAll(newCompletions); modelCompletions = newModelCompletions; } catch (SQLException e) { logger.error("Failed to update the metadata conmpletions", e); } } public static Set<String> getSqlKeywordsCompletions(Connection connection) throws IOException, SQLException { // Add the default SQL completions String keywords = new BufferedReader( new InputStreamReader(SqlCompleter.class.getResourceAsStream("/ansi.sql.keywords"))).readLine(); Set<String> completions = new TreeSet<>(); if (null != connection) { DatabaseMetaData metaData = connection.getMetaData(); // Add the driver specific SQL completions String driverSpecificKeywords = "/" + metaData.getDriverName().replace(" ", "-").toLowerCase() + "-sql.keywords"; logger.info("JDBC DriverName:" + driverSpecificKeywords); if (SqlCompleter.class.getResource(driverSpecificKeywords) != null) { String driverKeywords = new BufferedReader( new InputStreamReader(SqlCompleter.class.getResourceAsStream(driverSpecificKeywords))) .readLine(); keywords += "," + driverKeywords.toUpperCase(); } // Add the keywords from the current JDBC connection try { keywords += "," + metaData.getSQLKeywords(); } catch (Exception e) { logger.debug("fail to get SQL key words from database metadata: " + e, e); } try { keywords += "," + metaData.getStringFunctions(); } catch (Exception e) { logger.debug("fail to get string function names from database metadata: " + e, e); } try { keywords += "," + metaData.getNumericFunctions(); } catch (Exception e) { logger.debug("fail to get numeric function names from database metadata: " + e, e); } try { keywords += "," + metaData.getSystemFunctions(); } catch (Exception e) { logger.debug("fail to get system function names from database metadata: " + e, e); } try { keywords += "," + metaData.getTimeDateFunctions(); } catch (Exception e) { logger.debug("fail to get time date function names from database metadata: " + e, e); } // Also allow lower-case versions of all the keywords keywords += "," + keywords.toLowerCase(); } StringTokenizer tok = new StringTokenizer(keywords, ", "); while (tok.hasMoreTokens()) { completions.add(tok.nextToken()); } return completions; } public static Set<String> getDataModelMetadataCompletions(Connection connection) throws SQLException { Set<String> completions = new TreeSet<>(); if (null != connection) { getColumnNames(connection.getMetaData(), completions); getSchemaNames(connection.getMetaData(), completions); } return completions; } private static void getColumnNames(DatabaseMetaData meta, Set<String> names) throws SQLException { try { ResultSet columns = meta.getColumns(meta.getConnection().getCatalog(), null, "%", "%"); try { while (columns.next()) { // Add the following strings: (1) column name, (2) table name String name = columns.getString("TABLE_NAME"); if (!isBlank(name)) { names.add(name); names.add(columns.getString("COLUMN_NAME")); // names.add(columns.getString("TABLE_NAME") + "." + columns.getString("COLUMN_NAME")); } } } finally { columns.close(); } logger.debug(Joiner.on(',').join(names)); } catch (Exception e) { logger.error("Failed to retrieve the column name", e); } } private static void getSchemaNames(DatabaseMetaData meta, Set<String> names) throws SQLException { try { ResultSet schemas = meta.getSchemas(); try { while (schemas.next()) { String schemaName = schemas.getString("TABLE_SCHEM"); if (!isBlank(schemaName)) { names.add(schemaName + "."); } } } finally { schemas.close(); } } catch (Exception e) { logger.error("Failed to retrieve the column name", e); } } // test purpose only WhitespaceArgumentDelimiter getSqlDelimiter() { return this.sqlDelimiter; } }