Java Getting String from another class returning null

Question

I currently have two constructors in one of my classes, one going to my main class, and the other to another class that has most of the methods that I use. The reason I don't use static methods for my second class that I have a constructor, is that I don't want the code to be used by any other source, just mine. Here are the two constructors:

PrisonProfessionalMain plugin;

public PPCommandAdminMenu(PrisonProfessionalMain instance)
{
    plugin = instance;
}

QuickMethods qm;
public PPCommandAdminMenu(QuickMethods instance)
{
    qm = instance;
}

Then I am calling a method from the QuickMethods class here:

qm.getConfigString(plugin, "prefix")

Apparently, whatever method I call from this class it returns null. I do not think it is what I put inside of the method, but here is the method from the other class:

public String getConfigString(PrisonProfessionalMain instance, String configvar)
{
    return colorize(instance.getConfig().getString(configvar));
}

I don't see a problem here, but I am wondering if I should use a static way instead. I want to try and stay away from static methods for the reason I stated above.

REMEMBER: Calling any other method from this class results in it returning null. I know this because in console it has a stack trace that reads it null. It says this on the line that is calling any method from this class.

I tried removing the Strings and instances from inside the method:

public String getConfigString()
{
    return System.out.println("test");
}

This still however, resulted in another null pointer, pointing at the line that I called the method on.

My question is: How would I have the QuickMethods class stop returning null upon calling methods/strings from it.

Your question is not clear.

Vy Do
– Vy Do

2015-05-08 02:12:31 +00:00
Commented May 8, 2015 at 2:12 — Vy Do
– Vy Do, Commented May 8, 2015 at 2:12
@DoNhuVy better now?

JarFile
– JarFile

2015-05-08 02:15:37 +00:00
Commented May 8, 2015 at 2:15 — JarFile
– JarFile, Commented May 8, 2015 at 2:15

Elliott Frisch · Accepted Answer · 2015-05-08 02:20:17Z

3

Only one constructor can be called at a time, given your code it appears you need to combine your constructors like,

QuickMethods qm;
PrisonProfessionalMain plugin;
public PPCommandAdminMenu(PrisonProfessionalMain plugin, QuickMethods qm)
{
    this.plugin = plugin;
    this.qm = qm;
}

Otherwise (by definition) one will be null.

Also,

public String getConfigString()
{
    return System.out.println("test");
}

isn't legal code because PrintStream.println() is void (and System.out is a PrintStream). You can use something like

String str = "test";
System.out.println(str);
return str;

edited May 8, 2015 at 2:20

answered May 8, 2015 at 2:12

Elliott Frisch

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2 Comments

JarFile Over a year ago

How would I make QuickMethods a variable in my main class to be with the constructor when registering the class with the constructor.

Elliott Frisch Over a year ago

@JarFile By creating an instance of QuickMethods? QuickMethods qmInstance = new QuickMethods(); would create a reference to an instance of QuickMethods.

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