Question

So these 2 files I am going to post are each in my DataBase package. The DBBinding class just needs to create an object with a string for the key and one for the value. Then the DBrecord is going to keep a collection of DBBindings that all have the same key string but diffrent value strings. For some reason I can not think/find the correct way to make a add method in DBrecord so that it calls the DBBinding class/objects constructor.

This is the method that is supposed to add the binding:

private void addRecord(String key_, String value_)
{
    //DBBinding myDBBinding=new DBBinding(key_, value_);//constructor not defined error
    //DBBinding myDBBinding(key_,value_);
    //DataBase.DBBinding myDBBinding=new DataBase.DBBinding(key_, value_);//constructor not defined error

}

Here’s the DBBinding code followed by the DBrecord code.

package DataBase;

public class DBBinding {

    private String key;
    private String value;

    public void DBBinding(String key_, String value_)
    {
        String key =new String(key_);
        String value=new String(value_);
    }

    //public String toString()
    //{return key+": "+value;}

}

and

package DataBase;
//package DataBase.*;
import DataBase.*;//did not help ... ?

public class DBrecord {

    boolean select;
    String key;
    //need some type of collection to keep bindings. 

    public void DBrecord()
    {
        DBrecord myRecord=new DBrecord();
        select=false;
    }

    private void addRecord(String key_, String value_)
    {
        //DBBinding myDBBinding=new DBBinding(key_, value_);//constructor not defined error
        //DBBinding myDBBinding(key_,value_);
        //DataBase.DBBinding myDBBinding=new DataBase.DBBinding(key_, value_);//constructor not defined error

    }

    public String toString()
    {
        //out put key first then all values in collection/group/record. use correct formatting. 
    }



}

Answer 1

In class DBBinding you must have public DBBinding(String key_, String value_), the void makes the “constructor” actually to a method 🙂

You have the same error in DBrecord.

By the way, don’t do this:

String key =new String(key_);

Strings are immutable, nothing can happen if you “share” them. But your code forces Java to create a new object for an absolutely identical value. So use just

String key = key_;

However, in your case even this is wrong, as you create a new local variable key “shadowing” the class variable key. Look here for an explanation.

So alltogether DBBinding should look like:

package DataBase;

public class DBBinding {

    private String key;
    private String value;

    public DBBinding(String key_, String value_)
    {
        key = key_;
        value =  value_;
    }
    ...
}