Performance improvement for DefaultConverter.convertToJSONPrimitive()

[ind1go]

It turns out it's much more efficient to avoid exceptions when trying alternatives types in DefaultConverter.convertToJSONPrimitive(). Instead we can do a bit of character parsing to more efficiently find the type before attempting to do the exception-throwing X.parseX().

The results on a 2019 Intel Macbook Pro for the following test code (which loops through a variety of test data 1000000 times) are:
Before: 27.31s
After: 0.76s
... which seems worth doing!

Test code:

public static void main(String[] args) {
    String[] testValues = new String[] { "test1", null, "true", "True", "", " ", " fdskhfdsf ", "0", "1", "1.1",
            "-1", "NaN", "-7.0-4.2", " 0 ", " true ", "+23", ".33", "-3e7", "-3.4", "-3.0E7", "false", "-3-",
            "-3.0EE7" };
    Class[] testTypes = new Class[] { String.class, null, Boolean.class, String.class, String.class, String.class,
            String.class, Long.class, Long.class, Double.class, Long.class, String.class, String.class,
            String.class, String.class, String.class, String.class, String.class, Double.class, Double.class,
            Boolean.class, String.class, String.class };
    Object[] values = new Object[] { "test1", null, Boolean.TRUE, "True", "", " ", " fdskhfdsf ", Long.valueOf(0),
            Long.valueOf(1), Double.valueOf(1.1), Long.valueOf(-1), "NaN", "-7.0-4.2", " 0 ", " true ", "+23",
            ".33", "-3e7", Double.valueOf(-3.4), Double.valueOf(-3.0E7), Boolean.FALSE, "-3-", "-3.0EE7" };
    DefaultConverter dc = new DefaultConverter();
    long time;
    long time2;

    int loopTotal = 1000000;
    time = System.nanoTime();
    for (int loop = 0; loop < loopTotal; loop++) {
        for (int i = 0; i < testValues.length; i++) {
            Object result = dc.convertToJSONPrimitive(testValues[i]);
            if (result != null) {
                if (!result.equals(values[i]))
                    throw new RuntimeException(
                            "Wrong value for " + i + ", got: " + result + "(" + result.getClass().getName()
                                    + ") expected: " + values[i] + "(" + values[i].getClass().getName() + ")");
                if (result.getClass() != testTypes[i]) {
                    throw new RuntimeException("Wrong type for " + i + ", got: " + result.getClass().getName()
                            + " expected " + testTypes[i].getName());
                }
            } else {
                if (values[i] != null)
                    throw new RuntimeException("Unexpected null");
            }
        }
    }
    time2 = System.nanoTime();
    System.err.println("Result time: " + String.format("%.2f", (time2 - time) * Math.pow(10, -9)));
}