Java jdbc2 MysqlDataSource已连接但无法发送查询

Question

我正在使用自己的类来保持jdbc MysqlDataSource类的持久连接（请参阅下面的代码）。然而，在工作正常一天后，它停止工作。仍在进行连接，但查询未通过。此外，当我发送新查询时，连接似乎处于休眠模式。除了我的SHOW PROCESSES中的时间变量不断上升，表明查询没有通过。

这可能是我的问题？

private final ExecutorService executor = Executors.newSingleThreadExecutor();
private final MysqlDataSource source = new MysqlDataSource();
private Connection connection;

public MysqlStore(String name, String server, int port, String user, String password) {
    source.setDatabaseName(name);
    source.setServerName(server);
    source.setPort(port);
    source.setUser(user);
    source.setPassword(password);
}

private Connection getConnection() {
    try {
        if (connection == null || !connection.isValid(1)) {
            connection = source.getConnection();
        }
        return connection;
    } catch (SQLException e) {
        e.printStackTrace();
        return null;
    }
}

public CompletableFuture<QueryResult> runQuery(String sqlText, Object... arguments) {
    CompletableFuture<QueryResult> resultFuture = new CompletableFuture<>();
    executor.submit(() -> {
        Connection connection = getConnection();
        try {
            PreparedStatement statement = connection.prepareStatement(sqlText);
            for (int i = 0; i < arguments.length; i++) {
                statement.setObject(i + 1, arguments[i]);
            }
            resultFuture.complete(new QueryResult(statement));
        } catch (SQLException e) {
            resultFuture.completeExceptionally(e);
        }
    });
    return resultFuture;
}

public CompletableFuture<Integer> runUpdate(String sqlText, Object... arguments) {
    CompletableFuture<Integer> resultFuture = new CompletableFuture<>();
    executor.submit(() -> {
        Connection connection = getConnection();
        try {
            PreparedStatement statement = connection.prepareStatement(sqlText);
            for (int i = 0; i < arguments.length; i++) {
                statement.setObject(i + 1, arguments[i]);
            }
            resultFuture.complete(statement.executeUpdate());
        } catch (SQLException e) {
            resultFuture.completeExceptionally(e);
        }
    });
    return resultFuture;
}

public CompletableFuture<Integer> runUpdateGetKey(String sqlText, Object... arguments) {
    CompletableFuture<Integer> resultFuture = new CompletableFuture<>();
    executor.submit(() -> {
        Connection connection = getConnection();
        try {
            PreparedStatement statement = connection.prepareStatement(sqlText, Statement.RETURN_GENERATED_KEYS);
            for (int i = 0; i < arguments.length; i++) {
                statement.setObject(i + 1, arguments[i]);
            }
            statement.executeUpdate();

            try (ResultSet res = statement.getGeneratedKeys()) {
                if (res.next()) {
                    resultFuture.complete(res.getInt(1));
                } else {
                    resultFuture.completeExceptionally(new IllegalStateException("Expected a generated key but found nothing."));
                }
            }
        } catch (SQLException e) {
            resultFuture.completeExceptionally(e);
        }
    });
    return resultFuture;
}

@Override
public void close() {
    try {
        executor.awaitTermination(1, TimeUnit.SECONDS);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    if (!executor.isTerminated()) {
        executor.shutdownNow();
    }
    try {
        if (connection != null && !connection.isClosed()) {
            connection.close();
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

public class QueryResult implements Closeable {
    PreparedStatement statement;
    ResultSet result;

    public QueryResult(PreparedStatement statement) {
        this.statement = statement;

        try {
            result = statement.executeQuery();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public ResultSet get() {
        return result;
    }

    @Override
    public void close() {
        try {
            if (result != null) {
                result.close();
            }

            if (statement != null) {
                statement.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}