Jackcess: getTable(aName) is null while getTableNames yields aName (among others)

Question

I am new to Jackcess (downloaded it today, version 4.0.4) and immediately running into troubles: Would anybody know, why db.getTable(aName) returns null whereas db.getTableNames() shows me that very aName among others?

Note that I am running it jointly with Apache Commons Lang 3.12.0 because I could not find Apache Commons Lang 3.10 as requested in the dependencies of Jackcess 4.0.4. But would this explain the behavior?

In the code below, "dbfile" and "tble" should still be defined according to your database. Unfortunately I cannot release my data base as it is proprietary. I am getting null from db.getTable(aName) no matter what the OPTION is. Obviously, any the code with OPTION!=1 is a work-around to find out whether the corresponding table name is within the database. When I run the code with OPTION=0, the output is:

That is it: [my table name]
Your table is null.

I would appreciate if you could share your ideas so I can make this example work.

import java.io.IOException;
import java.io.File;
import java.util.Set;

import com.healthmarketscience.jackcess.Database;
import com.healthmarketscience.jackcess.DatabaseBuilder;
import com.healthmarketscience.jackcess.Table;

public class JackcessTrial {

    private static final int OPTION = 0;
    
    public JackcessTrial() {
        super();
    }
    
    public void openSourceTable(File dbFile, String tbleName) {
        Database db = null;
        Table myTable = null;
        try {
            db = new DatabaseBuilder(dbFile).setReadOnly(true).open();
            if (db==null) {
                System.out.println("No database found.");
                return;
            }
            if (OPTION==1) {
                myTable = db.getTable(tbleName);
            } else {
                
                Set<String> names = db.getTableNames();
                for(String name : names) {
                    if (name.equals(tbleName)) {
                        System.out.println("That is it: "+name);
                        myTable = db.getTable(name);
                        break;
                    }
                }
            }
            if (myTable == null) {
                System.out.println("Your table is null.");
                db.close();
                return;
            }
            System.out.println("Got your table!");
            db.close();
        } catch(Exception e) {
            e.printStackTrace();
            db = null;
        }
    }
    
    public static void main(String args[]) throws IOException {
        File dbfile = ...;
        String tble = ...;
        JackcessTrial test = new JackcessTrial();
        test.openSourceTable(dbfile, tble);
    }
}

Answer 1

I was running in the same problem with a newer Access database (Office 2016, accdb files). Older files (mdb) were running without issues, getTable was working fine.

If you check the length of the table names which are returned by iteration through getTableNames, you will recognize that the Strings has double length than your original table name. So every 2nd char is a char of 0. It seems to be a bug at jackcess. I fixed it in my code with a small function:

String getJackcessTableName(String tableName) {
    var result = new StringBuilder();
    char nullChar = 0;
    for (int i = 0; i < tableName.length(); i++) {
        result.append(tableName.charAt(i)).append(nullChar);
    }
    return result.toString();
}

If getTable(tbleName) returns null, I try with getTable(getJackcessTableName(tbleName)). Not nice, but works right now.