Which double value args make String.format result asterisk

Question

I write a location SDK, and the SDK produces android.location.Location instance. When the user calls the Location.toString() method to get readable text.

In the Location.toString method, I find code like below

@Override
public String toString() {
    StringBuilder s = new StringBuilder();
    s.append("Location[");
    s.append(mProvider);
    s.append(String.format(" %.6f,%.6f", mLatitude, mLongitude));
    if (hasAccuracy()) s.append(String.format(" hAcc=%.0f", mHorizontalAccuracyMeters));
    else s.append(" hAcc=???");
    if (mTime == 0) {
        s.append(" t=?!?");
    }
    if (mElapsedRealtimeNanos == 0) {
        s.append(" et=?!?");
    } else {
        s.append(" et=");
        TimeUtils.formatDuration(mElapsedRealtimeNanos / 1000000L, s);
    }
    if (hasAltitude()) s.append(" alt=").append(mAltitude);
    if (hasSpeed()) s.append(" vel=").append(mSpeed);
    if (hasBearing()) s.append(" bear=").append(mBearing);
    if (hasVerticalAccuracy()) s.append(String.format(" vAcc=%.0f", mVerticalAccuracyMeters));
    else s.append(" vAcc=???");
    if (hasSpeedAccuracy()) s.append(String.format(" sAcc=%.0f", mSpeedAccuracyMetersPerSecond));
    else s.append(" sAcc=???");
    if (hasBearingAccuracy()) s.append(String.format(" bAcc=%.0f", mBearingAccuracyDegrees));
    else s.append(" bAcc=???");
    if (isFromMockProvider()) s.append(" mock");

    if (mExtras != null) {
        s.append(" {").append(mExtras).append('}');
    }
    s.append(']');
    return s.toString();
}

My subclass implemention is

@Override
public String toString() {
    String superString = super.toString();
    return "ErrorCode[" + mErrorCode + "]," +
            "FromCached[" + mFromCache + "]," +
            superString;
}

result

ErrorCode[0],FromCached[false], Location[network "31******,114****** acc=559 et=+1d19h24m40s624ms]" 

what latitude and longitude may produce the weird result?

I tried Double.NaN , Double.POSITIVE_INFINITY , Double.MIN_VALUE , but I cannot get this strange result.

Answer 1

More of a guess: you are probably looking at the wrong toString() implementation.

It might be that your actual Location is of a subclass of that. One that is concerned about "privacy" and therefore masks part of that location string.

That is something that is very common: you want to ensure that sensitive information isn't going directly into logs or trace files. So you write a small wrapper that well, masks essential parts of the output, for example using * characters.