将结果集值传递给另一个类

Question

I have 2 java classes, one being color.java and the other being size.java. The color class has my SQL statement pulling from multiple tables and my result set. What I'm trying to do is pass in the itemno and description from color into size. Once I pass those values into size.java it will do additional logic and then come back to color.java to finish.

I've tried using something like this:

public void getValues(String color.rs.itemno, String color.rs.description){
return itemno;
return description;
}

I'm new to java so I may not be on the right track, but looking at other examples I think it goes something like the above.

Answer 1

you need to collect all values from a result set in a container, array or arraylist or other, loop through them and then pass whatever you need to your function. Seen here

(String color.rs.itemno, String color.rs.description)

can should be changed to

(String itemno, String description)

Answer 2

Okay so there are a couple of things wrong with the above code:

1. Currently, you have what is known as a mutator method. This is a method which does not return a value. Instead this is used to perform operations within an object, usually passing several parameters through it. In order to return a value, you will make use of an accessor method. For this, you need to state the data type you wish to return.
2. Next, you have named your variables incorrectly. You may wish to look at this document for the naming conversions here: https://www.javatpoint.com/java-naming-conventions What you have created now, are temporary variables only accessible within that method.
3. Lastly, you cannot return more than one variable at once. The nearest path will be taken and then the code stops running from there. So in your case, you would only be returning itemno and then the code will stop.

Here is an example how the code should look like keeping the above in mind:

String itemDescription;
int itemNumber;

public void setItemNo(int in)
{
    itemNumber = in;
}

public void setItemDescription(String id)
{
    itemDescription = id;
}

public int getItemNo()
{
    return itemNumber;
}

public String getItemDescription()
{
    return itemDescription;
}

I would however recommend making use of a constructor to set these values in the beginning:

public ClassName(int in, String id)
{
    itemNumber = in;
    itemDescription = id;
}