oglimmer/ggo

package de.oglimmer.ggo.db;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.function.Consumer;
import java.util.function.Function;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public enum DBAccess {
    DB;

    <R> R execOnCon(Function<Connection, R> fkt) {
        try (Connection conn = ConnectionPool.INSTANCE.getCon()) {
            return fkt.apply(conn);
        } catch (SQLException e) {
            log.error("Failed to exec query", e);
            return null;
        }
    }

    int execQuery(String query, Consumer<ResultSet> callback, Object... params) {
        return DB.execOnCon(con -> {
            try {
                try (PreparedStatement preparedStmt = con.prepareStatement(query)) {
                    int i = 1;
                    for (Object param : params) {
                        preparedStmt.setObject(i++, param);
                    }
                    try (ResultSet rs = preparedStmt.executeQuery()) {
                        int count = 0;
                        while (rs.next()) {
                            count++;
                            callback.accept(rs);
                        }
                        return count;
                    }
                }
            } catch (SQLException e) {
                log.error("Failed to execQuery", e);
            }
            return 0;
        });
    }

    int executeUpdate(String sql, Object... params) {
        return DB.execOnCon(con -> {
            try {
                try (PreparedStatement preparedStmt = con.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)) {
                    int i = 1;
                    for (Object param : params) {
                        preparedStmt.setObject(i++, param);
                    }
                    preparedStmt.executeUpdate();
                    try (ResultSet rs = preparedStmt.getGeneratedKeys()) {
                        if (rs.next()) {
                            return rs.getInt(1);
                        }
                    }
                }
            } catch (SQLException e) {
                log.error("Failed to executeUpdate", e);
            }
            return 0;
        });
    }

}