hive jdbc连接Demo

/** * 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.hadoop.hive.jdbc; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Properties; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hive.metastore.api.FieldSchema; import org.apache.hadoop.hive.metastore.api.Schema; import org.apache.hadoop.hive.serde2.SerDe; import org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils.ObjectInspectorCopyOption; import org.apache.hadoop.hive.serde2.objectinspector.StructField; import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector; import org.apache.hadoop.hive.service.HiveInterface; import org.apache.hadoop.io.BytesWritable; public class HiveQueryResultSet extends HiveBaseResultSet{ public static final Log LOG; private HiveInterface client; private SerDe serde; private int maxRows = 0; private int rowsFetched = 0; private Statement statement; public HiveQueryResultSet(HiveInterface client, Statement statement, int maxRows) throws SQLException { this(client, maxRows); this.statement = statement; } public HiveQueryResultSet(HiveInterface client, int maxRows) throws SQLException { this.client = client; this.maxRows = maxRows; initSerde(); this.row = Arrays.asList(new Object[this.columnNames.size()]); } public HiveQueryResultSet(HiveInterface client, Statement statement) throws SQLException { this(client); this.statement = statement; } public HiveQueryResultSet(HiveInterface client) throws SQLException { this(client, 0); } private void initSerde() throws SQLException { try { Schema fullSchema = this.client.getSchema(); List schema = fullSchema.getFieldSchemas(); this.columnNames = new ArrayList(); this.columnTypes = new ArrayList(); StringBuilder namesSb = new StringBuilder(); StringBuilder typesSb = new StringBuilder(); if ((schema != null) && (!schema.isEmpty())) { for (int pos = 0; pos < schema.size(); ++pos) { if (pos != 0) { namesSb.append(","); typesSb.append(","); } this.columnNames.add(((FieldSchema)schema.get(pos)).getName()); this.columnTypes.add(((FieldSchema)schema.get(pos)).getType()); namesSb.append(((FieldSchema)schema.get(pos)).getName()); typesSb.append(((FieldSchema)schema.get(pos)).getType()); } } String names = namesSb.toString(); String types = typesSb.toString(); this.serde = new LazySimpleSerDe(); Properties props = new Properties(); if (names.length() > 0) { LOG.info(new StringBuilder().append("Column names: ").append(names).toString()); props.setProperty("columns", names); } if (types.length() > 0) { LOG.info(new StringBuilder().append("Column types: ").append(types).toString()); props.setProperty("columns.types", types); } this.serde.initialize(new Configuration(), props); } catch (Exception ex) { ex.printStackTrace(); throw new SQLException(new StringBuilder().append("Could not create ResultSet: ").append(ex.getMessage()).toString()); } } public void close() throws SQLException { this.client = null; } public boolean next() throws SQLException { if ((this.maxRows > 0) && (this.rowsFetched >= this.maxRows)) { return false; } String rowStr = ""; try { /** added by shingo.yamagami@ksk-sol.jp **/ try { rowStr = this.client.fetchOne(); } catch (Exception exception) { } /** added by shingo.yamagami@ksk-sol.jp **/ this.rowsFetched += 1; if (LOG.isDebugEnabled()) { LOG.debug(new StringBuilder().append("Fetched row string: ").append(rowStr).toString()); } if (!"".equals(rowStr)) { StructObjectInspector soi = (StructObjectInspector)this.serde.getObjectInspector(); List fieldRefs = soi.getAllStructFieldRefs(); Object data = this.serde.deserialize(new BytesWritable(rowStr.getBytes())); assert (this.row.size() == fieldRefs.size()) : new StringBuilder().append(this.row.size()).append(", ").append(fieldRefs.size()).toString(); for (int i = 0; i < fieldRefs.size(); ++i) { StructField fieldRef = (StructField)fieldRefs.get(i); ObjectInspector oi = fieldRef.getFieldObjectInspector(); Object obj = soi.getStructFieldData(data, fieldRef); this.row.set(i, convertLazyToJava(obj, oi)); } if (LOG.isDebugEnabled()) { LOG.debug(new StringBuilder().append("Deserialized row: ").append(this.row).toString()); } } } catch (Exception ex) { ex.printStackTrace(); throw new SQLException("Error retrieving next row"); } return !"".equals(rowStr); } private static Object convertLazyToJava(Object o, ObjectInspector oi) { /* 186 */ Object obj = ObjectInspectorUtils.copyToStandardObject(o, oi, ObjectInspectorUtils.ObjectInspectorCopyOption.JAVA); /* 190 */ if ((obj != null) && (oi.getCategory() != ObjectInspector.Category.PRIMITIVE)) { /* 191 */ obj = obj.toString(); } /* 194 */ return obj; } static { LOG = LogFactory.getLog(HiveQueryResultSet.class); } @Override public <T> T getObject(int arg0, Class<T> arg1) throws SQLException { // TODO Auto-generated method stub return null; } @Override public <T> T getObject(String arg0, Class<T> arg1) throws SQLException { // TODO Auto-generated method stub return null; } }