Java - escape double quotes and slashes in html

class Main {

  public static void main(String[] args) {

    String str = "<div name=\"hey\">content</div>";

System.out.println(str);

    

str = str.replace("\"", "\\\"") ;   

str = str.replace("/", "\\/") ;   

System.out.println(str);

  }

}

Android - redirect user to play store for installing app

Intent viewIntent =
        new Intent("android.intent.action.VIEW",
                Uri.parse("https://play.google.com/store/apps/details?id=com.google.android.apps.ondemand.consumer"));
_mainActivity.startActivity(viewIntent);

Android - uninstall app programmatically

private void uninstallPackage(String name) {
    Intent intent = new Intent(Intent.ACTION_DELETE);
    intent.putExtra(Intent.EXTRA_RETURN_RESULT, true);
    intent.setData(Uri.parse("package:"+name));
    startActivity(intent);
}

private boolean doesPackageExist(String name){
    PackageManager pm=getPackageManager();
    try {
        PackageInfo info=pm.getPackageInfo(name,PackageManager.GET_META_DATA);
    } catch (PackageManager.NameNotFoundException e) {
        return false;
    }
    return true;
}

private void checkUninstallStatus(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1) {
        if (resultCode == RESULT_OK) {
            Log.d("TAG", "onActivityResult: user accepted the (un)install");
        } else if (resultCode == RESULT_CANCELED) {
            Log.d("TAG", "onActivityResult: user canceled the (un)install");
        } else if (resultCode == RESULT_FIRST_USER) {
            Log.d("TAG", "onActivityResult: failed to (un)install");
        }
    }
}

@Override
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
    checkUninstallStatus(requestCode,resultCode,data);
}

Probabilistic algorithms

https://www.safaribooksonline.com/oriole/probabilistic-data-structures-in-python

Set Cardinality - HyperLogLog

Set Membership - With False positives but no False negatives - Bloom Filter

Set similarity (document similarity) - MinHash with Jaccard

Frequency Summaries (Leaderboards in games) - Count-min sketch

Streaming Quantiles - stream of data where you have to aggregate metrics without stopping - T-Digest (like min/max/percentile)

Java print current stack trace

StringWriter sw = new StringWriter();
new Throwable().printStackTrace(new PrintWriter(sw));

//And to actually print it
Log.e("tag","Current stack trace is:\n" + sw.toString());

Git show entire history of a file

git log --pretty=format:"%h" <filePath> | xargs -I % git show % <filepath>