Testing strings in switch statements with Java 1.7

StringSwitch.java

public class StringSwitch {
    public static void main(String... args) {
        System.out.println("String x = new String(\"asdf\");");
        System.out.println("String y = new String(\"asdf\");");
        System.out.println("String z = \"asdf\";");
        String x = new String("asdf");
        String y = new String("asdf");
        String z = "asdf";

        System.out.format("x == y     : %s\n", x==y ? "true" : "false");
        System.out.format("x.equals(y): %s\n", x.equals(y) ? "true" : "false");
        System.out.format("x == z     : %s\n", x==z ? "true" : "false");
        System.out.format("x.equals(z): %s\n", x.equals(z) ? "true" : "false");
        System.out.format("y == z     : %s\n", y==z ? "true" : "false");
        System.out.format("y.equals(z): %s\n", y.equals(z) ? "true" : "false");

        switch(x) {
            case "asdf":
                System.out.println("switch(x) case \"asdf\": true");
                break;
            case "jkl;":
                System.out.println("switch(x) Shouldn't happen.");
                break;
            default:
                System.out.println("switch(x) None of the above.");
                break;
        }

        switch (z) {
            case "asdf":
                System.out.println("switch(z) case \"asdf\": true");
                break;
            case "jkl;":
                System.out.println("switch(z) Shouldn't happen.");
                break;
            default:
                System.out.println("switch(x) None of the above.");
                break;
        }

        /*
         * The following fails with the error 
         * "constant string expression required."
        switch (x) {
            case y:
                System.out.println("switch(x) case y: true");
                break;
            default:
                System.out.println("switch(x) case y: false");
        }

        switch (x) {
            case z:
                System.out.println("switch(x) case z: true");
                break;
            default:
                System.out.println("switch(x) case z: false");
        }
        
        switch (z) {
            case y:
                System.out.println("switch(z) case y: true");
                break;
            default:
                System.out.println("switch(z) case y: false");
        }
        switch (x) {
            case new String("asdf"):
                System.out.println("switch(x) case new String(\"asdf\"): true");
                break;
            case new String("jkl;"):
                System.out.println("switch(x) Shouldn't happen.");
                break;
            default:
                System.out.println("switch(x) None of the above.");
                break;
        }

        switch (z) {
            case new String("asdf"):
                System.out.println("switch(z) case new String(\"asdf\"): true");
                break;
            case "jkl;":
                System.out.println("switch(z) Shouldn't happen.");
                break;
            default:
                System.out.println("switch(z) None of the above.");
                break;
        }
        */
    }
}
/*
 * And now for the results:
 *
 * String x = new String("asdf");
 * String y = new String("asdf");
 * String z = "asdf";
 * x == y     : false
 * x.equals(y): true
 * x == z     : false
 * x.equals(z): true
 * y == z     : false
 * y.equals(z): true
 * switch(x) case "asdf": true
 * switch(z) case "asdf": true 
 * 
 * Failed tests:
 *    - using variables for the case in the switch statement
 *    - using new instances of the String class in the switch statement
 */