LightPIT: src/main/java/de/uapcore/lightpit/dao/Functions.java@822b7e3d064d

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  *

     4  * Copyright 2018 Mike Becker. All rights reserved.

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions are met:

     8  *

     9  *   1. Redistributions of source code must retain the above copyright

    10  *      notice, this list of conditions and the following disclaimer.

    11  *

    12  *   2. Redistributions in binary form must reproduce the above copyright

    13  *      notice, this list of conditions and the following disclaimer in the

    14  *      documentation and/or other materials provided with the distribution.

    15  *

    16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    26  * POSSIBILITY OF SUCH DAMAGE.

    27  *

    28  */

    29 package de.uapcore.lightpit.dao;

    31 import java.sql.*;

    32 import java.util.ArrayList;

    33 import java.util.List;

    34 import java.util.Optional;

    35 import java.util.function.Function;

    37 /**

    38  * Some DAO utilities.

    39  */

    40 public final class Functions {

    42     public static String getSafeString(ResultSet rs, String column) throws SQLException {

    43         return Optional.ofNullable(rs.getString(column)).orElse("");

    44     }

    46     public static void setStringOrNull(PreparedStatement stmt, int index, String str) throws SQLException {

    47         if (str == null || str.isBlank()) {

    48             stmt.setNull(index, Types.VARCHAR);

    49         } else {

    50             stmt.setString(index, str);

    51         }

    52     }

    54     public static void setDateOrNull(PreparedStatement stmt, int index, Date date) throws SQLException {

    55         if (date == null) {

    56             stmt.setNull(index, Types.DATE);

    57         } else {

    58             stmt.setDate(index, date);

    59         }

    60     }

    62     public static <T> void setForeignKeyOrNull(PreparedStatement stmt, int index, T instance, Function<? super T, Integer> keyGetter) throws SQLException {

    63         Integer key = Optional.ofNullable(instance).map(keyGetter).orElse(null);

    64         if (key == null) {

    65             stmt.setNull(index, Types.INTEGER);

    66         } else {

    67             stmt.setInt(index, key);

    68         }

    69     }

    71     @FunctionalInterface

    72     public interface ResultSetMapper<T> {

    73         T apply(ResultSet rs) throws SQLException;

    74     }

    76     public static <T> List<T> list(PreparedStatement stmt, ResultSetMapper<T> mapper) throws SQLException {

    77         List<T> results = new ArrayList<>();

    78         try (var result = stmt.executeQuery()) {

    79             while (result.next()) {

    80                 final var project = mapper.apply(result);

    81                 results.add(project);

    82             }

    83         }

    84         return results;

    85     }

    87     public static <T> T find(PreparedStatement stmt, ResultSetMapper<T> mapper) throws SQLException {

    88         try (var result = stmt.executeQuery()) {

    89             if (result.next()) {

    90                 final var ent = mapper.apply(result);

    91                 return ent;

    92             } else {

    93                 return null;

    94             }

    95         }

    96     }

    98     private Functions() {

   100     }

   101 }

Mercurial > hg > LightPIT / file revision

src/main/java/de/uapcore/lightpit/dao/Functions.java@822b7e3d064d

src/main/java/de/uapcore/lightpit/dao/Functions.java