feat: add fetch size, max-rows, timeout settings

resources/application.properties

@@ -2,3 +2,6 @@ app.datasource.url=jdbc:postgresql://localhost:5434/charm_repository
 app.datasource.username=postgres
 app.datasource.password=123456
 app.datasource.driver=org.postgresql.Driver
+app.datasource.fetch-size=50
+app.datasource.max-rows=100
+app.datasource.query-timeout=5

src/ru/charm/back/controller/ProfileController.java

@@ -10,8 +10,10 @@ import jakarta.servlet.annotation.WebServlet;
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import ru.charm.back.dto.ProfileFilter;
 import ru.charm.back.dto.ProfileGetDto;
 import ru.charm.back.dto.ProfileUpdateDto;
+import ru.charm.back.mapper.RequestToProfileFilterMapper;
 import ru.charm.back.mapper.RequestToProfileUpdateDtoMapper;
 import ru.charm.back.service.ProfileService;
 
@@ -27,6 +29,8 @@ public class ProfileController extends HttpServlet {
     private final ProfileService service = ProfileService.getInstance();
 
     private final RequestToProfileUpdateDtoMapper requestToProfileUpdateDtoMapper = RequestToProfileUpdateDtoMapper.getInstance();
+    private final RequestToProfileFilterMapper requestToProfileFilterMapper = RequestToProfileFilterMapper.getInstance();
+
 
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
@@ -66,7 +70,8 @@ public class ProfileController extends HttpServlet {
                 resp.sendError(SC_NOT_FOUND);
             }
         } else {
-            req.setAttribute("profiles", service.findAll());
+            ProfileFilter filter = requestToProfileFilterMapper.map(req);
+            req.setAttribute("profiles", service.findAll(filter));
             req.getRequestDispatcher("/WEB-INF/jsp/profiles.jsp").forward(req, resp);
         }
     }

src/ru/charm/back/controller/rest/ProfileController.java

@@ -9,7 +9,9 @@ import jakarta.servlet.annotation.WebServlet;
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import ru.charm.back.dto.ProfileFilter;
 import ru.charm.back.dto.ProfileGetDto;
+import ru.charm.back.mapper.RequestToProfileFilterMapper;
 import ru.charm.back.service.ProfileService;
 
 import java.io.IOException;
@@ -23,6 +25,8 @@ import static ru.charm.back.utils.UrlUtils.REST_URL;
 @MultipartConfig
 public class ProfileController extends HttpServlet {
     private final ProfileService service = ProfileService.getInstance();
+    private final RequestToProfileFilterMapper requestToProfileFilterMapper = RequestToProfileFilterMapper.getInstance();
+
 
     private final ObjectMapper objectMapper = JsonMapper.builder()
             .configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true)
@@ -45,7 +49,8 @@ public class ProfileController extends HttpServlet {
                     resp.sendError(SC_NOT_FOUND);
                 }
             } else {
-                objectMapper.writeValue(writer, service.findAll());
+                ProfileFilter filter = requestToProfileFilterMapper.map(req);
+                objectMapper.writeValue(writer, service.findAll(filter));
             }
         }
     }

src/ru/charm/back/dao/ProfileDao.java

@@ -4,38 +4,39 @@ import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
+import ru.charm.back.dto.ProfileFilter;
+import ru.charm.back.dto.ProfileSelectQueryBuilder;
+import ru.charm.back.dto.ProfileUpdateQueryBuilder;
+import ru.charm.back.dto.Query;
 import ru.charm.back.model.Gender;
 import ru.charm.back.model.Profile;
 import ru.charm.back.model.Role;
 import ru.charm.back.model.Status;
-import ru.charm.back.utils.ConfigFile;
+import ru.charm.back.utils.ConfigFileUtils;
+import ru.charm.back.utils.ConnectionManager;
 
 import java.sql.*;
 import java.sql.Date;
 import java.util.*;
 
+import static ru.charm.back.utils.ConnectionManager.getConnection;
+
 @Slf4j
 @NoArgsConstructor(access = AccessLevel.PRIVATE)
 public class ProfileDao {
 
+    public static final String INSERT = "INSERT INTO profile (email, password) VALUES (?, ?)";
     private static final ProfileDao INSTANCE = new ProfileDao();
-    public static final String URL = ConfigFile.get("app.datasource.url");
-    public static final String USER = ConfigFile.get("app.datasource.username");
-    public static final String PASSWORD = ConfigFile.get("app.datasource.password");
-    public static final String DRIVER = ConfigFile.get("app.datasource.driver");
-
 
     @SneakyThrows
     public static ProfileDao getInstance() {
-        Class.forName(DRIVER);
         return INSTANCE;
     }
 
     public Profile save(Profile profile) {
-        String sql = "INSERT INTO profile(email, password) VALUES (?, ?)";
         try (
-                Connection connection = DriverManager.getConnection(URL, USER, PASSWORD);
+                Connection connection = getConnection();
-                PreparedStatement statement = connection.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);
+                PreparedStatement statement = connection.prepareStatement(INSERT, Statement.RETURN_GENERATED_KEYS);
         ) {
 
             statement.setString(1, profile.getEmail());
@@ -54,13 +55,15 @@ public class ProfileDao {
         }
     }
 
+
     public Optional<Profile> findById(Long id) {
+        Query query = new ProfileSelectQueryBuilder().addIdFilter(id).build();
+
         try (
-                Connection connection = DriverManager.getConnection(URL, USER, PASSWORD);
+                Connection connection = getConnection();
-                Statement statement = connection.createStatement();
+                PreparedStatement statement = ConnectionManager.getPreparedStmt(connection, query);
         ) {
-            String sql = "SELECT * FROM profile WHERE id = '%s'".formatted(id);
+            ResultSet res = statement.executeQuery();
-            ResultSet res = statement.executeQuery(sql);
 
             Profile profile = null;
             if (res.next()) {
@@ -74,13 +77,24 @@ public class ProfileDao {
         }
     }
 
-    public List<Profile> findAll() {
+    public List<Profile> findAll(ProfileFilter filter) {
+        Query query = new ProfileSelectQueryBuilder()
+                .addEmailStartWithFilter(filter.getEmailStartWith())
+                .addNameStartWith(filter.getNameStartWith())
+                .addSurnameStartWith(filter.getSurnameStartWith())
+                .addStatus(filter.getStatus())
+                .addLTAge(filter.getLtAge())
+                .addGTEAge(filter.getGteAge())
+                .build();
+
         try (
-                Connection connection = DriverManager.getConnection(URL, USER, PASSWORD);
+                Connection connection = ConnectionManager.getConnection();
-                Statement statement = connection.createStatement();
+                PreparedStatement statement = ConnectionManager.getPreparedStmt(connection, query);
         ) {
-            String sql = "SELECT * FROM profile" ;
+            statement.setFetchSize(ConnectionManager.FETCH_SIZE);
-            ResultSet res = statement.executeQuery(sql);
+            statement.setMaxRows(ConnectionManager.MAX_ROWS);
+            statement.setQueryTimeout(ConnectionManager.QUERY_TIMEOUT);
+            ResultSet res = statement.executeQuery();
 
             List<Profile> profiles = new ArrayList<>();
             while (res.next()) {
@@ -94,81 +108,32 @@ public class ProfileDao {
         }
     }
 
-    public Optional<Profile> findByEmailAndPassword(String email, String password) {
-        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
-             Statement stmt = conn.createStatement()) {
-            //language=POSTGRES-PSQL
-            String sql = "SELECT * FROM profile WHERE email = '%s' AND password = '%s'";
-
-            ResultSet rs = stmt.executeQuery(String.format(sql, email, password));
-
-            Profile profile = null;
-            if (rs.next()) {
-                profile = mapToProfile(rs);
-            }
-            return Optional.ofNullable(profile);
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
     public void update(Profile profile) {
-        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
+        Query query = new ProfileUpdateQueryBuilder()
-             Statement stmt = conn.createStatement()) {
+                .addEmail(profile.getEmail())
-            List<Object> args = new ArrayList<>();
+                .addPassword(profile.getPassword())
-            StringBuilder queryBuilder = new StringBuilder("UPDATE profile SET email = '%s', password = '%s'");
+                .addName(profile.getName())
-            args.add(profile.getEmail());
+                .addSurname(profile.getSurname())
-            args.add(profile.getPassword());
+                .addBirthDate(profile.getBirthDate())
+                .addAbout(profile.getAbout())
+                .addGender(profile.getGender())
+                .addStatus(profile.getStatus())
+                .addPhoto(profile.getPhoto())
+                .build(profile.getId());
 
-            if (profile.getName() != null) {
+        try (Connection conn = ConnectionManager.getConnection();
-                queryBuilder.append(", name = '%s'");
+             PreparedStatement stmt = ConnectionManager.getPreparedStmt(conn, query)) {
-                args.add(profile.getName());
+            stmt.executeUpdate();
-            }
-            if (profile.getSurname() != null) {
-                queryBuilder.append(", surname = '%s'");
-                args.add(profile.getSurname());
-            }
-            if (profile.getBirthDate() != null) {
-                queryBuilder.append(", birth_date = '%s'");
-                args.add(Date.valueOf(profile.getBirthDate()));
-            }
-            if (profile.getAbout() != null) {
-                queryBuilder.append(", about = '%s'");
-                args.add(profile.getAbout());
-            }
-            if (profile.getGender() != null) {
-                queryBuilder.append(", gender = '%s'");
-                args.add(profile.getGender());
-            }
-            if (profile.getStatus() != null) {
-                queryBuilder.append(", status = '%s'");
-                args.add(profile.getStatus());
-            }
-            if (profile.getPhoto() != null) {
-                queryBuilder.append(", photo = '%s'");
-                args.add(profile.getPhoto());
-            }
-
-            queryBuilder.append(" WHERE id = %s");
-            args.add(profile.getId());
-
-            String sql = queryBuilder.toString().formatted(args.toArray());
-            log.debug("Final update sql: {}", sql);
-
-            int updateCount = stmt.executeUpdate(sql);
-            log.debug("Update count: {}", updateCount);
         } catch (SQLException e) {
             throw new RuntimeException(e);
         }
     }
 
     public boolean delete(Long id) {
-        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
+        String sql = "DELETE FROM profile WHERE id = ?";
-             Statement stmt = conn.createStatement()) {
+        try (Connection conn = getConnection();
-            //language=POSTGRES-PSQL
+             PreparedStatement stmt = conn.prepareStatement(sql)) {
-            String sql = "DELETE FROM profile WHERE id = %s".formatted(id);
+            int deleteCount = stmt.executeUpdate();
-
-            int deleteCount = stmt.executeUpdate(sql);
             log.debug("Delete count: {}", deleteCount);
             return deleteCount > 0;
         } catch (SQLException e) {
@@ -178,7 +143,7 @@ public class ProfileDao {
 
     public Set<String> getAllEmails() {
         try (
-                Connection connection = DriverManager.getConnection(URL, USER, PASSWORD);
+                Connection connection = getConnection();
                 Statement statement = connection.createStatement();
         ) {
             String sql = "SELECT email FROM profile" ;
@@ -197,11 +162,11 @@ public class ProfileDao {
     }
 
     public Optional<Profile> findByEmail(String email) {
-        String sql = "SELECT * FROM profile WHERE email = ?";
+        Query query = new ProfileSelectQueryBuilder().addEmailFilter(email).build();
 
         try (
-                Connection connection = DriverManager.getConnection(URL, USER, PASSWORD);
+                Connection connection = ConnectionManager.getConnection();
-                PreparedStatement statement = connection.prepareStatement(sql);
+                PreparedStatement statement = ConnectionManager.getPreparedStmt(connection, query);
         ) {
             statement.setString(1, email);
             ResultSet res = statement.executeQuery();
@@ -219,12 +184,13 @@ public class ProfileDao {
     }
 
     public Boolean existsByEmail(String email) {
+        Query query = new ProfileSelectQueryBuilder().addEmailFilter(email).build();
+
         try (
-                Connection connection = DriverManager.getConnection(URL, USER, PASSWORD);
+            Connection connection = ConnectionManager.getConnection();
-                Statement statement = connection.createStatement();
+            PreparedStatement statement = ConnectionManager.getPreparedStmt(connection, query);
         ) {
-            String sql = "SELECT * FROM profile WHERE email = '%s'".formatted(email);
+            ResultSet res = statement.executeQuery();
-            ResultSet res = statement.executeQuery(sql);
 
             return res.next();
 

src/ru/charm/back/dto/ProfileFilter.java

@@ -0,0 +1,17 @@
+package ru.charm.back.dto;
+
+import lombok.AccessLevel;
+import lombok.Data;
+import lombok.experimental.FieldDefaults;
+import ru.charm.back.model.Status;
+
+@Data
+@FieldDefaults(level = AccessLevel.PRIVATE)
+public class ProfileFilter {
+    String emailStartWith;
+    String nameStartWith;
+    String surnameStartWith;
+    Integer ltAge;
+    Integer gteAge;
+    Status status;
+}

src/ru/charm/back/dto/ProfileSelectQueryBuilder.java

@@ -0,0 +1,115 @@
+package ru.charm.back.dto;
+
+
+import ru.charm.back.model.Status;
+
+import java.sql.Date;
+import java.util.ArrayList;
+import java.util.List;
+
+import static ru.charm.back.utils.DateTimeUtils.getPastDate;
+
+
+public class ProfileSelectQueryBuilder {
+    //language=POSTGRES-PSQL
+    public static final String SELECT_BASE = """
+            SELECT id, email, password, "name", surname, birth_date, about, gender, photo, status, role
+            FROM profile
+            WHERE '' = ''
+            """;
+
+    private final StringBuilder sb;
+    private final List<Object> args;
+
+    public ProfileSelectQueryBuilder() {
+        this.sb = new StringBuilder(SELECT_BASE);
+        this.args = new ArrayList<>();
+    }
+
+    public ProfileSelectQueryBuilder addIdFilter(Long id) {
+        if (id == null) {
+            return this;
+        }
+        sb.append(" AND id = ?");
+        args.add(id);
+        return this;
+    }
+
+    public ProfileSelectQueryBuilder addEmailFilter(String email) {
+        if (email == null) {
+            return this;
+        }
+        sb.append(" AND email = ?");
+        args.add(email);
+        return this;
+    }
+
+    public ProfileSelectQueryBuilder addPasswordFilter(String password) {
+        if (password == null) {
+            return this;
+        }
+        sb.append(" AND password = ?");
+        args.add(password);
+        return this;
+    }
+
+    public ProfileSelectQueryBuilder addEmailStartWithFilter(String emailStartWith) {
+        if (emailStartWith == null) {
+            return this;
+        }
+        sb.append(" AND email like ?");
+        args.add(emailStartWith + "%");
+        return this;
+    }
+
+    public ProfileSelectQueryBuilder addNameStartWith(String nameStartWith) {
+        if (nameStartWith == null) {
+            return this;
+        }
+        sb.append(" AND name like ?");
+        args.add(nameStartWith + "%");
+        return this;
+    }
+
+    public ProfileSelectQueryBuilder addSurnameStartWith(String surnameStartWith) {
+        if (surnameStartWith == null) {
+            return this;
+        }
+        sb.append(" AND surname like ?");
+        args.add(surnameStartWith + "%");
+        return this;
+    }
+
+    public ProfileSelectQueryBuilder addLTAge(Integer ltAge) {
+        if (ltAge == null) {
+            return this;
+        }
+        Date gtDate = getPastDate(ltAge);
+        sb.append(" AND birth_date > ?");
+        args.add(gtDate);
+        return this;
+    }
+
+    public ProfileSelectQueryBuilder addGTEAge(Integer gteAge) {
+        if (gteAge == null) {
+            return this;
+        }
+        Date lteDate = getPastDate(gteAge);
+        sb.append(" AND birth_date <= ?");
+        args.add(lteDate);
+        return this;
+    }
+
+    public ProfileSelectQueryBuilder addStatus(Status status) {
+        if (status == null) {
+            return this;
+        }
+        sb.append(" AND status = ?");
+        args.add(status.toString());
+        return this;
+    }
+
+    public Query build() {
+        return new Query(sb.toString(), args);
+    }
+}

src/ru/charm/back/dto/ProfileUpdateQueryBuilder.java

@@ -0,0 +1,109 @@
+package ru.charm.back.dto;
+
+import ru.charm.back.model.Gender;
+import ru.charm.back.model.Status;
+
+import java.sql.Date;
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ProfileUpdateQueryBuilder {
+    //language=POSTGRES-PSQL
+    public static final String UPDATE_BASE = "UPDATE profile SET id = id";
+
+    private final StringBuilder sb;
+    private final List<Object> args;
+
+    public ProfileUpdateQueryBuilder() {
+        this.sb = new StringBuilder(UPDATE_BASE);
+        this.args = new ArrayList<>();
+    }
+
+    public ProfileUpdateQueryBuilder addEmail(String email) {
+        if (email == null) {
+            return this;
+        }
+        sb.append(", email = ?");
+        args.add(email);
+        return this;
+    }
+
+    public ProfileUpdateQueryBuilder addPassword(String password) {
+        if (password == null) {
+            return this;
+        }
+        sb.append(", password = ?");
+        args.add(password);
+        return this;
+    }
+
+    public ProfileUpdateQueryBuilder addName(String name) {
+        if (name == null) {
+            return this;
+        }
+        sb.append(", name = ?");
+        args.add(name);
+        return this;
+    }
+
+    public ProfileUpdateQueryBuilder addSurname(String surname) {
+        if (surname == null) {
+            return this;
+        }
+        sb.append(", surname = ?");
+        args.add(surname);
+        return this;
+    }
+
+    public ProfileUpdateQueryBuilder addBirthDate(LocalDate birthDate) {
+        if (birthDate == null) {
+            return this;
+        }
+        sb.append(", birth_date = ?");
+        args.add(Date.valueOf(birthDate));
+        return this;
+    }
+
+    public ProfileUpdateQueryBuilder addAbout(String about) {
+        if (about == null) {
+            return this;
+        }
+        sb.append(", about = ?");
+        args.add(about);
+        return this;
+    }
+
+    public ProfileUpdateQueryBuilder addGender(Gender gender) {
+        if (gender == null) {
+            return this;
+        }
+        sb.append(", gender = ?");
+        args.add(gender.toString());
+        return this;
+    }
+
+    public ProfileUpdateQueryBuilder addStatus(Status status) {
+        if (status == null) {
+            return this;
+        }
+        sb.append(", status = ?");
+        args.add(status.toString());
+        return this;
+    }
+
+    public ProfileUpdateQueryBuilder addPhoto(String photo) {
+        if (photo == null) {
+            return this;
+        }
+        sb.append(", photo = ?");
+        args.add(photo);
+        return this;
+    }
+
+    public Query build(Long id) {
+        sb.append(" WHERE id = ?");
+        args.add(id);
+        return new Query(sb.toString(), args);
+    }
+}

src/ru/charm/back/dto/Query.java

@@ -0,0 +1,6 @@
+package ru.charm.back.dto;
+
+import java.util.List;
+
+public record Query(String sql, List<Object> args) {
+}

src/ru/charm/back/mapper/RequestToProfileFilterMapper.java

@@ -0,0 +1,54 @@
+package ru.charm.back.mapper;
+
+import jakarta.servlet.http.HttpServletRequest;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import ru.charm.back.dto.ProfileFilter;
+import ru.charm.back.model.Status;
+
+import static ru.charm.back.utils.StringUtils.isBlank;
+
+
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public class RequestToProfileFilterMapper implements Mapper<HttpServletRequest, ProfileFilter> {
+
+	private static final RequestToProfileFilterMapper INSTANCE = new RequestToProfileFilterMapper();
+
+	public static RequestToProfileFilterMapper getInstance() {
+		return INSTANCE;
+	}
+
+	@Override
+	public ProfileFilter map(HttpServletRequest req) {
+		return map(req, new ProfileFilter());
+	}
+
+	@Override
+	public ProfileFilter map(HttpServletRequest req, ProfileFilter filter) {
+		String emailStartWithArg = req.getParameter("emailStartWith");
+		String emailStartWith = isBlank(emailStartWithArg) ? null : emailStartWithArg;
+		filter.setEmailStartWith(emailStartWith);
+
+		String nameStartWithArg = req.getParameter("nameStartWith");
+		String nameStartWith = isBlank(nameStartWithArg) ? null : nameStartWithArg;
+		filter.setNameStartWith(nameStartWith);
+
+		String surnameStartWithArg = req.getParameter("surnameStartWith");
+		String surnameStartWith = isBlank(surnameStartWithArg) ? null : surnameStartWithArg;
+		filter.setSurnameStartWith(surnameStartWith);
+
+		String ltAgeArg = req.getParameter("ltAge");
+		Integer ltAge = isBlank(ltAgeArg) ? null : Integer.parseInt(ltAgeArg);
+		filter.setLtAge(ltAge);
+
+		String gteAgeArg = req.getParameter("gteAge");
+		Integer gteAge = isBlank(gteAgeArg) ? null : Integer.parseInt(gteAgeArg);
+		filter.setGteAge(gteAge);
+
+		String statusArg = req.getParameter("status");
+		Status status = isBlank(statusArg) ? null : Status.valueOf(statusArg);
+		filter.setStatus(status);
+
+		return filter;
+	}
+}

src/ru/charm/back/service/ProfileService.java

@@ -4,10 +4,7 @@ import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 import lombok.SneakyThrows;
 import ru.charm.back.dao.ProfileDao;
-import ru.charm.back.dto.LoginDto;
+import ru.charm.back.dto.*;
-import ru.charm.back.dto.ProfileGetDto;
-import ru.charm.back.dto.ProfileUpdateDto;
-import ru.charm.back.dto.RegistrationDto;
 import ru.charm.back.mapper.ProfileToProfileGetDtoMapper;
 import ru.charm.back.mapper.ProfileUpdateDtoToProfileMapper;
 import ru.charm.back.mapper.RegistrationDtoToProfileMapper;
@@ -46,8 +43,8 @@ public class ProfileService {
         return dao.findById(id).map(profileToProfileGetDtoMapper::map);
     }
 
-    public List<ProfileGetDto> findAll() {
+    public List<ProfileGetDto> findAll(ProfileFilter filter) {
-        return dao.findAll().stream().map(profileToProfileGetDtoMapper::map).toList();
+        return dao.findAll(filter).stream().map(profileToProfileGetDtoMapper::map).toList();
     }
 
     @SneakyThrows

src/ru/charm/back/utils/ConfigFileUtils.java

@@ -7,7 +7,7 @@ import java.io.InputStream;
 import java.util.Properties;
 
 @UtilityClass
-public class ConfigFile {
+public class ConfigFileUtils {
     private static final Properties CONFIG = new Properties();
 
     static {
@@ -20,7 +20,7 @@ public class ConfigFile {
 
 
     private static void loadConfig() {
-        try (InputStream resourceAsStream = ConfigFile.class.getClassLoader().getResourceAsStream("application.properties")) {
+        try (InputStream resourceAsStream = ConfigFileUtils.class.getClassLoader().getResourceAsStream("application.properties")) {
             CONFIG.load(resourceAsStream);
         } catch (IOException e) {
             throw new RuntimeException(e);

src/ru/charm/back/utils/ConnectionManager.java

@@ -0,0 +1,48 @@
+package ru.charm.back.utils;
+
+import lombok.SneakyThrows;
+import lombok.experimental.UtilityClass;
+import ru.charm.back.dto.Query;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.util.List;
+
+@UtilityClass
+public class ConnectionManager {
+    public static final String URL = ConfigFileUtils.get("app.datasource.url");
+    public static final String USER = ConfigFileUtils.get("app.datasource.username");
+    public static final String PASSWORD = ConfigFileUtils.get("app.datasource.password");
+    public static final String DRIVER = ConfigFileUtils.get("app.datasource.driver");
+    private static final String FETCH_SIZE_STR = ConfigFileUtils.get("app.datasource.fetch-size");
+    public static final int FETCH_SIZE = Integer.parseInt(FETCH_SIZE_STR != null ? FETCH_SIZE_STR : "100");
+    private static final String MAX_ROWS_STR = ConfigFileUtils.get("app.datasource.max-rows");
+    public static final int MAX_ROWS = Integer.parseInt(MAX_ROWS_STR != null ? MAX_ROWS_STR : "1000");
+    private static final String QUERY_TIMEOUT_STR = ConfigFileUtils.get("app.datasource.query-timeout");
+    public static final int QUERY_TIMEOUT = Integer.parseInt(QUERY_TIMEOUT_STR != null ? QUERY_TIMEOUT_STR : "10");
+
+    static {
+        if (DRIVER != null) {
+            try {
+                Class.forName(DRIVER);
+            } catch (ClassNotFoundException e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+
+    public static Connection getConnection() throws SQLException {
+        return DriverManager.getConnection(URL, USER, PASSWORD);
+    }
+
+    public static PreparedStatement getPreparedStmt(Connection conn, Query query) throws SQLException {
+        PreparedStatement stmt = conn.prepareStatement(query.sql());
+        List<Object> args = query.args();
+        for (int i = 0; i < args.size(); i++) {
+            stmt.setObject(i + 1, args.get(i));
+        }
+        return stmt;
+    }
+}

src/ru/charm/back/utils/DateTimeUtils.java

@@ -0,0 +1,25 @@
+package ru.charm.back.utils;
+
+import lombok.experimental.UtilityClass;
+
+import java.sql.Date;
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
+
+@UtilityClass
+public class DateTimeUtils {
+
+    public static int getAge(LocalDate birthDate) {
+        return Math.toIntExact(ChronoUnit.YEARS.between(birthDate, LocalDate.now()));
+    }
+
+    public static Date getPastDate(int age) {
+        return Date.valueOf(LocalDate.now().minusYears(age));
+    }
+
+    public static boolean isValidAge(LocalDate birthDate) {
+        if (birthDate == null) return false;
+        int age = getAge(birthDate);
+        return age > 18 && age < 100;
+    }
+}