qwang6 commented on a change in pull request #506: add hive metadata jdbc retrieval URL: https://github.com/apache/griffin/pull/506#discussion_r305420279
########## File path: service/src/main/java/org/apache/griffin/core/metastore/hive/HiveMetaStoreServiceJdbcImpl.java ########## @@ -0,0 +1,287 @@ +/* +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.griffin.core.metastore.hive; + +import org.apache.hadoop.hive.metastore.api.FieldSchema; +import org.apache.hadoop.hive.metastore.api.StorageDescriptor; +import org.apache.hadoop.hive.metastore.api.Table; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import org.springframework.beans.factory.annotation.Qualifier; +import org.springframework.beans.factory.annotation.Value; +import org.springframework.cache.annotation.CacheConfig; +import org.springframework.cache.annotation.CacheEvict; +import org.springframework.cache.annotation.Cacheable; +import org.springframework.scheduling.annotation.Scheduled; +import org.springframework.stereotype.Service; + +import java.sql.*; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +@Service +@Qualifier(value = "hive_jdbc") +@CacheConfig(cacheNames = "jdbchive", keyGenerator = "cacheKeyGenerator") +public class HiveMetaStoreServiceJdbcImpl implements HiveMetaStoreService { + + private static final Logger LOGGER = LoggerFactory + .getLogger(HiveMetaStoreService.class); + + @Value("${hive.jdbc.className}") + private String hiveClassName; + + @Value("${hive.jdbc.url}") + private String hiveUrl; + + private Connection conn; + + public void setConn(Connection conn) { + this.conn = conn; + } + + public void setHiveClassName(String hiveClassName) { + this.hiveClassName = hiveClassName; + } + + @Override + @Cacheable(unless = "#result==null") + public Iterable<String> getAllDatabases() { + String sql = "show databases"; + return queryHiveString(sql); + } + + @Override + @Cacheable(unless = "#result==null") + public Iterable<String> getAllTableNames(String dbName) { + String sql = "show tables in " + dbName; + return queryHiveString(sql); + } + + @Override + @Cacheable(unless = "#result==null") + public Map<String, List<String>> getAllTableNames() { + // Not recommend this method because this method will generate one query for every database + // If there has a lots of databases in Hive, this method will lead to Griffin crash + Map<String, List<String>> res = new HashMap<>(); + + for (String dbName : getAllDatabases()) { + List<String> list = (List<String>) queryHiveString("show tables in " + dbName); + res.put(dbName, list); + } + + return res; + } + + @Override + public List<Table> getAllTable(String db) { + return null; + } + + @Override + public Map<String, List<Table>> getAllTable() { + return null; + } + + @Override + @Cacheable(unless = "#result==null") + public Table getTable(String dbName, String tableName) { + Table result = new Table(); + result.setDbName(dbName); + result.setTableName(tableName); + + try { + Class.forName(hiveClassName); + if (conn == null) { + conn = DriverManager.getConnection(hiveUrl); + } + } catch (ClassNotFoundException | SQLException e) { + e.printStackTrace(); + } + + LOGGER.info("got connection"); + + String sql = "show create table " + dbName + "." + tableName; + Statement stmt = null; + ResultSet rs = null; + StringBuilder sb = new StringBuilder(); + + try { + stmt = conn.createStatement(); + rs = stmt.executeQuery(sql); + while (rs.next()) { + String s = rs.getString(1); + sb.append(s); + } + String location = getLocation(sb.toString()); + List<FieldSchema> cols = getColums(sb.toString()); + StorageDescriptor sd = new StorageDescriptor(); + sd.setLocation(location); + sd.setCols(cols); + result.setSd(sd); + } catch (Exception e) { + e.printStackTrace(); + } finally { + closeConnection(conn, stmt, rs); + } + return result; + } + + @Scheduled(fixedRateString = + "${cache.evict.hive.fixedRate.in.milliseconds}") + @CacheEvict( + cacheNames = "hivejdbc", + allEntries = true, + beforeInvocation = true) + public void evictHiveCache() { + LOGGER.info("Evict hive cache"); + } + + private void closeConnection(Connection conn, Statement stmt, ResultSet rs) { + try { + if (rs != null) { + rs.close(); + } + if (stmt != null) { + stmt.close(); + } + if (conn != null) { + conn.close(); + } + } catch (SQLException e) { + e.printStackTrace(); + } + } + + /** + * Query Hive for Show tables or show databases, which will return List of String + * @param sql sql string + * @return + */ + private Iterable<String> queryHiveString(String sql) { + List<String> res = new ArrayList<>(); + Statement stmt = null; + ResultSet rs = null; + + try { + Class.forName(hiveClassName); + if (conn == null) { + conn = DriverManager.getConnection(hiveUrl); + } + LOGGER.info("got connection"); + } catch (ClassNotFoundException | SQLException e) { + e.printStackTrace(); + } + + try { + stmt = conn.createStatement(); + rs = stmt.executeQuery(sql); + while (rs.next()) { + res.add(rs.getString(1)); + } + } catch (Exception e) { + e.printStackTrace(); + } finally { + closeConnection(conn, stmt, rs); + } + return res; + } + + /** + * Get the Hive table location from hive table metadata string + * @param tableMetadata hive table metadata string + * @return Hive table location + */ + public String getLocation(String tableMetadata) { + tableMetadata = tableMetadata.toLowerCase(); + int index = tableMetadata.indexOf("location"); + if (index == -1) { + return ""; + } + + int start = tableMetadata.indexOf("\'", index); + int end = tableMetadata.indexOf("\'", start + 1); + + if (start == -1 || end == -1) { + return ""; + } + + return tableMetadata.substring(start + 1, end); + } + + /** + * Get the Hive table schema: column name, column type, column comment + * @param tableMetadata hive table metadata string + * @return List of FieldSchema + */ + public List<FieldSchema> getColums(String tableMetadata) { Review comment: done ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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