Connecting to SQLite from Java. Getting some disorder in commands

Question

I have a factory class which "builds" different database connectors using one and the same interface. I have no trouble with MySQL and Postgre, but I do get some troubles when I try to connect and run some queries against SQLite database. So, this is the disorder I see:

SQL db = SQL_Factory.build("SQLite");
System.out.println("BEFORE CONNECT");
db.connect();
System.out.println("BEFORE SHOW");
List<String> tables = db.show_tables();

and inside connect() method I have these debugging commands:

try{
    cnx = DriverManager.getConnection("jdbc:sqlite:" + db_path);
    System.out.println("CONNECTED");
} 
....

As a result of running the code I expected to see this in the console:

BEFORE CONNECT
CONNECTED
BEFORE SHOW

However, what I see looks rather strange:

BEFORE CONNECT
BEFORE SHOW
CONNECTED

Indeed, I'm getting a lot of other errors, but it's quite obvious, that all of them result from this disorder - CONNECTED status appears long after other commands that need this connection to be set. So, I wonder where this async behaviour may come from and how to repair it? Thanks!

EDIT

Well, on the official page I see extremely strange lines of code:

connection = DriverManager.getConnection("jdbc:sqlite:sample.db");
Statement statement = connection.createStatement();
statement.setQueryTimeout(30);  // <- WTF?????????

statement.executeUpdate("drop table if exists person");

So, is it really necessary to set timeout?? It looks like rubbish.

Answer 1

I created a quick-and-dirty test.

Db.java

class Db {
Connection conn;



public Db() {
    try {
        Class.forName("org.sqlite.JDBC");
    }
    catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
}



void connect(String dbPath) throws SQLException {
    try {
        conn = DriverManager.getConnection("jdbc:sqlite:" + dbPath);
    }
    finally {
    }
}



void doStuff() throws SQLException {
    Statement statement = null;
    try {
        statement = conn.createStatement();
        // statement.setQueryTimeout(30);
        statement.executeUpdate("drop table if exists person");
    }
    finally {
        if (statement != null) {
            statement.close();
        }
    }
}



void disconnect() throws SQLException {
    try {
        conn.close();
    }
    finally {
        conn = null;
    }
}
}

Main.java

class Main {

public static void main(String[] args) throws SQLException {
    Db db = new Db();
    System.out.println("b4 connect");
    db.connect("justATest");
    System.out.println("connected");
    db.doStuff();
    System.out.println("done some stuff, disconnecting....");
    db.disconnect();
    System.out.println("disconnected");
}
}

Using jdk 1.8 over windows7, maven 3.3 and sqlite 3.8.11.2, the console output is as follows

Unfortunately I have no means of carrying out tests on a different OS.