How to have global values inside a class?

I want less methods. I want a common global TestClass from which I could use any of its value inside the class.

import java.util.*;
import java.io.*;

public class TestClass {
    TestClass(String hello){
        String hallo = hello;
        String halloSecond = "Saluto!";
    }

    public static void main(String[] args) {
        TestClass test = new TestClass("Tjena!");
        System.out.println("I want "Tjena!": " + test.hallo);
        TestClass testSecond = new TestClass("1");
        System.out.println("I want Saluto!:" + test.halloSecond);
        System.out.println("I want Saluto!:" + testSecond.halloSecond);

        // How can I get glob.vars like the "Saluto!"?
    }
}

[Clarification Needed] I cannot understand the no-use of GLOB.VARS. Please, see the code below where you cannot access the GLOB.VARS without an instance, hence the error. If I guarantee no malicious code can make an instance, is there any problem in using GLOB.vars?

$ javac TestClass.java 
TestClass.java:19: non-static variable hallo cannot be referenced from a static context
  System.out.println("It did not get to the GLOB.VAR: " + hallo);
                                             ^
1 error

With this class:

import java.util.*;
import java.io.*;

public class TestClass {

    public String hallo;
    public String halloSecond;

    TestClass(String hello){
        hallo = hello;
        halloSecond = "Saluto!";
    }

    public static void main(String[] args) {
        TestClass test = new TestClass("Tjena!");
        System.out.println("It did not get to the GLOB.VAR" + hallo);
    }

}

Solution

I guess you are looking for something like this:

public class TestClass {
    public final String hallo;
    public static final String halloSecond = "Saluto!";

    TestClass(String hello){
        String hallo = hello;
    }

    public static void main(String[] args) {
        TestClass test = new TestClass("Tjena!");
        System.out.println("I want "Tjena!": " + test.hallo);
        TestClass testSecond = new TestClass("1");
        System.out.println("I want Saluto!:" + test.halloSecond);
        System.out.println("I want Saluto!:" + testSecond.halloSecond);
    }
}

The value of hallo is set in each instance of TestClass. The value of halloSecond is a constant, shared by all instances of the class and visible for the whole app. Note that with this code your IDE/compiler probably gives you a warning upon test.halloSecond - it should be qualified by the class name, like TestClass.halloSecond, rather than an instance name.

Update on global variables: the main problem with global variables is that they make the code

harder to understand - if a method uses global variables, you can't see simply from its signature what data is it actually manipulating
harder to test - same method is difficult to test isolated in unit tests, as you have to (re)set all global variables it depends on to the desired state before each unit test
harder to maintain - global variables create dependencies, which easily make the code into a tangled mess where everything depends on everything else

In Java everything is inside a class, so you can't have "classic" global variables like in C/C++. However, a public static data member is still in fact a global variable.

Note that the code sample above, halloSecond is a global constant, not a variable (as it is declared final and is immutable), which alleviates much of these problems (except maybe the dependency issue).