Java tutorial
/** * Licensed to the Austrian Association for Software Tool Integration (AASTI) * under one or more contributor license agreements. See the NOTICE file * distributed with this work for additional information regarding copyright * ownership. The AASTI 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.openengsb.core.edbi.jdbc; import java.util.Collection; import java.util.Iterator; import java.util.List; import javax.sql.DataSource; import org.apache.commons.lang.StringUtils; import org.openengsb.core.edbi.jdbc.sql.PrimaryKeyConstraint; import org.openengsb.core.edbi.jdbc.sql.Table; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate; import org.springframework.jdbc.core.namedparam.SqlParameterSource; /** * JdbcService holds a DataSource and provides several helper methods for spring-jdbc. */ public class JdbcService { private DataSource dataSource; private JdbcTemplate jdbc; private NamedParameterJdbcTemplate jdbcn; public JdbcService(DataSource dataSource) { this.dataSource = dataSource; } public JdbcTemplate jdbc() { if (jdbc == null) { jdbc = new JdbcTemplate(dataSource); } return jdbc; } public NamedParameterJdbcTemplate jdbcn() { if (jdbcn == null) { jdbcn = new NamedParameterJdbcTemplate(dataSource); } return jdbcn; } public DataSource getDataSource() { return dataSource; } public <T> T queryForObject(String sql, Class<T> type) { return jdbc().queryForObject(sql, type); } public <T> T queryForObject(String sql, Class<T> type, Object... args) { return jdbc().queryForObject(sql, type, args); } public Boolean queryForBoolean(String sql, Object... args) { return queryForObject(sql, Boolean.class, args); } public long count(String table) { return queryForObject("SELECT COUNT(*) FROM " + table, Long.class); } public long count(String table, String where, Object... args) { return queryForObject("SELECT COUNT(*) FROM " + table + " WHERE " + where, Long.class, args); } public int insert(String table, String columns, Object... args) { String sql = String.format("INSERT INTO `%s` (%s) VALUES (%s)", table, columns, StringUtils.repeat("?", ",", args.length)); return jdbc().update(sql, args); } public int insert(String table, String[] columns, Object[] args) { return insert(table, StringUtils.join(columns, ","), args); } public int insert(String table, Object... args) { String sql = String.format("INSERT INTO `%s` VALUES (%s)", table, StringUtils.repeat("?", ",", args.length)); return jdbc().update(sql, args); } public int[] insert(String table, Collection<String> columns, SqlParameterSource[] records) { String columnList = StringUtils.join(columns, ","); String placeholders = ":" + StringUtils.join(columns, ",:"); String sql = String.format("INSERT INTO `%s` (%s) VALUES (%s)", table, columnList, placeholders); return jdbcn().batchUpdate(sql, records); } public int[] insert(Table table, List<IndexRecord> records) { List<String> columns = table.getColumns().getColumnNames(); return insert(table.getName(), columns, toParameterSourceArray(records)); } public int[] update(String table, Collection<String> columns, String whereClause, SqlParameterSource[] records) { String setClauseList = makeNamedSetClauseList(columns); String sql = String.format("UPDATE `%s` SET %s WHERE %s", table, setClauseList, whereClause); return jdbcn().batchUpdate(sql, records); } public int[] update(Table table, List<IndexRecord> records) { List<String> columns = table.getColumns().getColumnNames(); String whereClause = makeWhereClause(table.getPrimaryKey()); // FIXME: find an elegant solution for a dynamic SET clause within an UPDATE statement for batch updates // either column exclusions or find subsets of columns within the list of IndexRecords IndexRecord record = records.get(0); columns.retainAll(record.getValues().keySet()); return update(table.getName(), columns, whereClause, toParameterSourceArray(records)); } public int[] delete(String table, String whereClause, SqlParameterSource[] records) { String sql = String.format("DELETE FROM `%s` WHERE %s", table, whereClause); return jdbcn().batchUpdate(sql, records); } public int[] delete(Table table, List<IndexRecord> records) { String whereClause = makeWhereClause(table.getPrimaryKey()); return delete(table.getName(), whereClause, toParameterSourceArray(records)); } protected SqlParameterSource[] toParameterSourceArray(List<? extends SqlParameterSource> list) { return list.toArray(new SqlParameterSource[list.size()]); } protected String makeNamedSetClauseList(Collection<String> parameters) { return joinNamedParameters(parameters, "=", ","); } protected String makeWhereClause(PrimaryKeyConstraint key) { return joinNamedParameters(key.getColumns(), "=", " AND "); } protected String joinNamedParameters(Collection<String> parameters, String glue, String delimiter) { StringBuilder str = new StringBuilder(parameters.size() * 20); Iterator<String> iterator = parameters.iterator(); while (iterator.hasNext()) { String parameter = iterator.next(); str.append(parameter); str.append(glue); str.append(" :"); str.append(parameter); if (iterator.hasNext()) { str.append(delimiter); } } return str.toString(); } }