Error: cannot resolve symbol' on Person (java.lang.String, java.lang.String)

**baltimore** · 08-05-2007, 10:31 PM

Hi, I'm sure this is really simple, I can't figure out why this is happening. First, the code.

Java Code:

public abstract class BusinessObject {
    public Vector validationMessage;
    protected HashMap data = new HashMap();
    public HashMap read () {
       return data;
    }
}

Java Code:

public abstract class Person extends BusinessObject {
    public Person() {
    }
    public Person (String nameString) {
        String newLast = "";
        String newFirst = "";
        if ( nameString.indexOf(",") != -1 ) {
            newLast = nameString.substring( 0, nameString.indexOf(",") );
            newFirst = nameString.substring( nameString.indexOf(",") + 1, nameString.length() );
        } else if ( nameString.indexOf(" " ) != -1 ) {
            newFirst = nameString.substring( 0, nameString.indexOf(" ") );
            newLast = nameString.substring( nameString.indexOf(" ") + 1, nameString.length() );
        }
        Person(newLast, newFirst);
    }
    public Person (String newNameLast, String newNameFirst) {
        data.put("nameLast", newNameLast);
        data.put("nameFirst", newNameFirst);
    }
}

When I try to compile Person.java, the compiler tells me that at the line Person(newLast, newFirst); inside the Person (String nameString) constructor, it 'cannot resolve symbol' on Person (java.lang.String, java.lang.String). I've moved the last Person constructor above the others, between the others, etc., but I know that shouldn't make a difference.
I've tried casting newLast = (String) nameString.substring(... and that doesn't work.
Thanks.

**hardwired** · 08-06-2007, 07:45 AM

The way to call another constructor is with the "this" keyword. And it must be the first line in the constructor. I don't see any clean way of doing it here. You'll have to add the two strings to the map in this single–argument constructor.

Java Code:

public Person (String nameString) {
    this(string1, string2);
    ...
}

I came up with this but it's a little bizarre. Had to get rid of the abstract modifier to use it. Compiles and runs.

Java Code:

import java.util.*;

public class PersonTest {
    public static void main(String[] args) {
        Person john = new Person("Lucas,John");
        System.out.println("john = " + john);
    }
}

class Person extends BusinessObject {
    public Person() {
    }

    public Person (String newNameLast, String newNameFirst) {
        data.put("nameLast", newNameLast);
        data.put("nameFirst", newNameFirst);
    }

    public Person (String nameString) {
        this(Person.breakUp(nameString));
    }

    private Person(String[] names) {
        this(names[0], names[1]);
    }

    private static String[] breakUp(String nameString) {
        String newLast = "";
        String newFirst = "";
        if ( nameString.indexOf(",") != -1 ) {
            newLast = nameString.substring( 0, nameString.indexOf(",") );
            newFirst = nameString.substring( nameString.indexOf(",") + 1,
                                             nameString.length() );
        } else if ( nameString.indexOf(" " ) != -1 ) {
            newFirst = nameString.substring( 0, nameString.indexOf(" ") );
            newLast = nameString.substring( nameString.indexOf(" ") + 1,
                                            nameString.length() );
        }
        return new String[] { newLast, newFirst };
    }
}