h2db - Can´t connect with different Computer

Question

This class connects to Database via h2db.

   public class DatabaseServer {


    private final String user;
    private final String password;
    private final String database;
    private Connection conn = null;
    private Server webServer = null;
    private Server tcpServer = null;

    public DatabaseServer(String user, String password, String database) {
        this.user = user;
        this.password = password;
        this.database = database;

    }

    public void startServer() throws Exception {
        new Thread(() -> {
            try {
                webServer = Server.createWebServer("-webAllowOthers", "-webPort", "8092");
                webServer.start();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }).start();
        new Thread(() -> {
            try {
                tcpServer = Server.createTcpServer("-tcpAllowOthers", "-tcpPort", "55756");
                tcpServer.start();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }).start();
        //wait until the servers are created
        while (tcpServer == null || webServer == null) {
            Thread.sleep(40);
        }
    }

The error ocorred here:

public Connection getConnection() throws SQLException {
        String url = "jdbc:h2:" + tcpServer.getURL() + "/~/" + database;
        System.out.println("url: " + url);
        conn = DriverManager.getConnection(url, user, password);
        return conn;
    }

I have h2db in Server mode. User and Password are given in the constructor. The code works fine on my Computer, when I export to another computer and run it, gives me this error:

 org.h2.jdbc.JdbcSQLNonTransientConnectionException: Database "C:/Users/tomas/test" not found, either pre-create it or allow remote database creation (not recommended in secure environments) [90149-202]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:678)
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:477)
    at org.h2.message.DbException.get(DbException.java:223)
    at org.h2.message.DbException.get(DbException.java:199)
    at org.h2.engine.Engine.throwNotFound(Engine.java:189)
    at org.h2.engine.Engine.openSession(Engine.java:72)
    at org.h2.engine.Engine.openSession(Engine.java:222)
    at org.h2.engine.Engine.createSession(Engine.java:201)
    at org.h2.server.TcpServerThread.run(TcpServerThread.java:174)
    at java.base/java.lang.Thread.run(Thread.java:832)

Is the H2 database version the same as the one in your local computer? — hfontanez, Dec 06 '21 at 06:01
i don't have h2db in the other computer, its required? Im trying to build a java gui where it can be used by multiple computers — JavaGuest2000, Dec 06 '21 at 07:12
If the other computer doesn't have H2, I BELIEVE that you'd need to use H2 in-memory. This means that your connection URL must reflect that. — hfontanez, Dec 06 '21 at 12:45

score 0 · Answer 1 · answered Dec 17 '21 at 14:52

Database must be created on the server side before any attempts to use it on client side. A secure password should be used for the user specified during database creation, because this user will have ADMIN privileges in database and these privileges allow access to the system outside of database itself.

Remote database creation is not allowed by H2 any more, because it creates a remote security hole.

https://h2database.com/html/tutorial.html#creating_new_databases

h2db - Can´t connect with different Computer

1 Answers1