XAMPP on Windows 10

After installing XAMPP, any attempt to start Apache from the control panel was met with port blocked.
The solution is to right click and run as administrator. Then click the shell button and type: sc stop w3svc.
____________Screen shot shell_____________________________
Setting environment for using XAMPP for Windows.
sal@MYA55 c:\xampp
# sc stop w3svc

SERVICE_NAME: w3svc
TYPE : 20 WIN32_SHARE_PROCESS
STATE : 3 STOP_PENDING
(NOT_STOPPABLE, NOT_PAUSABLE, IGNORES_SHUTDOWN)
WIN32_EXIT_CODE : 0 (0x0)
SERVICE_EXIT_CODE : 0 (0x0)
CHECKPOINT : 0x1
WAIT_HINT : 0x4e20

sal@MYA55 c:\xampp
#
____________End of screen shot shell_________________
Now typing

http://localhost

in your browser should yield:

Windows 10 HP Envy 4500 Printer Offline

Resolved here.
Or here

X509 Trust Manager Interface Resolved

My Android app WAR had been using an imported version of the Application Crash Reports for Android (ACRA) library that was implemented incorrectly. The external JAR was acra-4.2.3.jar, which I automatically assumed to be outdated.

Therefore, I downloaded and copied acra-4.8.2.jar to the app/libs directory in Android Studio. Here are the series of steps that I took to find that updated ACRA jar file.

Started with a Bing search on acra-4.2.3.jar

SERP came back with

https://code.google.com/archive/p/acra/wikis/ACRA3HowTo.wiki

This led to

https://code.google.com/archive/p/acra/

Then to

https://github.com/ACRA/acra

Which pointed to

https://github.com/ACRA/acra/wiki/BasicSetup

Then

http://search.maven.org/#search%7Cga%7C1%7Cch.acra

And finally arriving at

https://repo1.maven.org/maven2/ch/acra/acra/4.8.2/acra-4.8.2.zip

After unzipping and copying the jar file to Android Studio app/libs directory, I modified the build.gradle file as follows:

dependencies {

    compile files('libs/httpmime-4.1.1.jar')

    compile files('libs/acra-4.8.2.jar')

}

Mission accomplished for now at least; however, I certainly realize that I may have just added to my tech debt, but if it's working now, I won't risk introducing new bugs.

X509 Trust Manager Interface

This is the warning letter from Google to fix the unsafe implementation of the interface X509TrustManager

My fix will be posted shortly.

Hello Google Play Developer,
Your app(s) listed at the end of this email use an unsafe implementation of the interface X509TrustManager. Specifically, the implementation ignores all SSL certificate validation errors when establishing an HTTPS connection to a remote host, thereby making your app vulnerable to man-in-the-middle attacks. An attacker could read transmitted data (such as login credentials) and even change the data transmitted on the HTTPS connection. If you have more than 20 affected apps in your account, please check the Developer Console for a full list. 
To properly handle SSL certificate validation, change your code in the checkServerTrusted method of your custom X509TrustManager interface to raise either CertificateException or IllegalArgumentException whenever the certificate presented by the server does not meet your expectations. For technical questions, you can post to Stack Overflow and use the tags “android-security” and “TrustManager.”
Please address this issue as soon as possible and increment the version number of the upgraded APK. Beginning May 17, 2016, Google Play will block publishing of any new apps or updates containing the unsafe implementation of the interface X509TrustManager.
To confirm you’ve made the correct changes, submit the updated version of your app to the Developer Console and check back after five hours. If the app hasn’t been correctly upgraded, we will display a warning.
While these specific issues may not affect every app with the TrustManager implementation, it’s best not to ignore SSL certificate validation errors. Apps with vulnerabilities that expose users to risk of compromise may be considered dangerous products in violation of the Content Policy and section 4.4 of the Developer Distribution Agreement.
Apps must also comply with the Developer Distribution Agreement and Content Policy. If you feel we have sent this warning in error, contact our policy support team through the Google Play Developer Help Center.
Regards,
The Google Play Team

©2016 Google Inc. 1600 Amphitheatre Parkway, Mountain View, CA 94043
Email preferences: You have received this mandatory email service announcement to update you about important changes to your Google Play Developer account.

Affected app(s), version(s), and class(es):
org.warmixare 
89 
org.acra.util.NaiveTrustManager;

org.warmixare2 
93 
org.acra.util.NaiveTrustManager;

Android and the Different Screen Sizes

First of all, visit the Android developer center.

The following images are from Stack Overflow

What is Hashing?

Culled directly from Webopedia

Producing hash values for accessing data or for security. A hash value (or simply hash), also called a message digest, is a number generated from a string of text. The hash is substantially smaller than the text itself, and is generated by a formula in such a way that it is extremely unlikely that some other text will produce the same hash value.

Hashes play a role in security systems where they're used to ensure that transmitted messages have not been tampered with. The sender generates a hash of the message, encrypts it, and sends it with the message itself. The recipient then decrypts both the message and the hash, produces another hash from the received message, and compares the two hashes. If they're the same, there is a very high probability that the message was transmitted intact. Hashing is also a common method of accessing data records. Consider, for example, a list of names:

John Smith

Sarah Jones

Roger Adams

To create an index, called a hash table,for these records, you would apply a formula to each name to produce a unique numeric value. So you might get something like:

1345873 John smith

3097905 Sarah Jones

4060964 Roger Adams

Then to search for the record containing Sarah Jones,you just need to reapply the formula, which directly yields the index key to the record. This is much more efficient than searching through all the records till the matching record is found.

Select Last Row of MySQL Table (Or the very first entry to the table)

Here are two ways where the table index is auto-incremented:

select * from myTable where myIndex = (select MAX(myIndex) from myTable); 

select * from myTable order by myIndex asc limit 1;

Which one is more efficient?

By the way, one can also select the latest entries from a MySQL table with:

select * from myTable order by myIndex desc limit 4;