diff options
Diffstat (limited to 'cps-ri/src/main/java/org/onap/cps/spi/repository/TempTableCreator.java')
-rw-r--r-- | cps-ri/src/main/java/org/onap/cps/spi/repository/TempTableCreator.java | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/cps-ri/src/main/java/org/onap/cps/spi/repository/TempTableCreator.java b/cps-ri/src/main/java/org/onap/cps/spi/repository/TempTableCreator.java new file mode 100644 index 0000000000..8cad9f5e4c --- /dev/null +++ b/cps-ri/src/main/java/org/onap/cps/spi/repository/TempTableCreator.java @@ -0,0 +1,97 @@ +/*- + * ============LICENSE_START======================================================= + * Copyright (C) 2022 Nordix Foundation. + * ================================================================================ + * 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. + * + * SPDX-License-Identifier: Apache-2.0 + * ============LICENSE_END========================================================= + */ + +package org.onap.cps.spi.repository; + +import java.util.Arrays; +import java.util.Collection; +import java.util.HashSet; +import java.util.Iterator; +import java.util.List; +import java.util.UUID; +import javax.persistence.EntityManager; +import javax.persistence.PersistenceContext; +import lombok.AllArgsConstructor; +import lombok.extern.slf4j.Slf4j; +import org.springframework.stereotype.Component; +import org.springframework.transaction.annotation.Transactional; + +@Slf4j +@Transactional +@AllArgsConstructor +@Component +public class TempTableCreator { + + @PersistenceContext + private EntityManager entityManager; + + /** + * Create a uniquely named temporary table. + * + * @param prefix prefix for the table name (so you can recognize it) + * @param sqlData data to insert (strings only) the inner List present a row of data + * @param columnNames column names (in same order as data in rows in sqlData) + * @return a unique temporary table name with given prefix + */ + public String createTemporaryTable(final String prefix, + final Collection<List<String>> sqlData, + final String... columnNames) { + final String tempTableName = prefix + UUID.randomUUID().toString().replace("-", ""); + final StringBuilder sqlStringBuilder = new StringBuilder("CREATE TEMPORARY TABLE "); + sqlStringBuilder.append(tempTableName); + defineColumns(sqlStringBuilder, columnNames); + insertData(sqlStringBuilder, tempTableName, columnNames, sqlData); + entityManager.createNativeQuery(sqlStringBuilder.toString()).executeUpdate(); + return tempTableName; + } + + private static void defineColumns(final StringBuilder sqlStringBuilder, final String[] columnNames) { + sqlStringBuilder.append('('); + final Iterator<String> it = Arrays.stream(columnNames).iterator(); + while (it.hasNext()) { + final String columnName = it.next(); + sqlStringBuilder.append(" "); + sqlStringBuilder.append(columnName); + sqlStringBuilder.append(" varchar NOT NULL"); + if (it.hasNext()) { + sqlStringBuilder.append(","); + } + } + sqlStringBuilder.append(");"); + } + + private static void insertData(final StringBuilder sqlStringBuilder, + final String tempTableName, + final String[] columnNames, + final Collection<List<String>> sqlData) { + final Collection<String> sqlInserts = new HashSet<>(sqlData.size()); + for (final Collection<String> row : sqlData) { + sqlInserts.add("('" + String.join("','", row) + "')"); + } + sqlStringBuilder.append("INSERT INTO "); + sqlStringBuilder.append(tempTableName); + sqlStringBuilder.append(" ("); + sqlStringBuilder.append(String.join(",", columnNames)); + sqlStringBuilder.append(") VALUES "); + sqlStringBuilder.append(String.join(",", sqlInserts)); + sqlStringBuilder.append(";"); + } + +} |