arch42 has a section to document the quality goal decisions of your system or software product. arch42 references the ISO 25010. This a great standard reference for solution architects to focus on the non-functional requirements important to the stakeholders. The purpose of this post is to show the ISO 25010 standard characteristics and sub-characteristics.
Disclaimer
This post is solely informative. Critically think before using any information presented. Learn from it but ultimately make your own decisions at your own risk.
Requirements
A solution architect working with stakeholders to document the 3–5 most important quality goal characteristics for a system or software product.
ISO 25010
Visit ISO 25010 to read more about the characteristics and sub-characteristics for product quality. Table 1 provides a summary. In general, these are all of the “-ility” statements.
Table 1 - ISO 25010 Quality Characteristics
Functional Stability
Performance Efficiency
Compatibility
Interaction Capability
Reliability
Security
Maintainability
Flexibility
Safety
Functional Completeness
Functional Correctness
Funcational Appropriateness
Time Behavior
Resource Utilization
Capacity
Co-Existence
Interoperability
Appropriateness Recognizability
Learnability
Operability
User Error Protection
User Engagement
Inclusivity
User Assistance
Self-Descriptiveness
Faultlessness
Availability
Fault Tolerance
Recoverability
Confidentiality
Integrity
Non-Repudiation
Accountability
Authenticity
Resistance
Compliance
Modularity
Reusability
Analysability
Modifiability
Testability
Adaptability
Scalability
Installability
Replaceability
Operational Constraint
Risk Identification
Fail Safe
Hazard Warning
Safe Integration
When deciding the quality goals used to architect and evaluate the system or software product, they should be listed as both characteristics and sub-characteristics as shown in Table 1.
Select-for-update is an SQL feature which I used to use all the time, but it seems like it’s use has fallen out of favor. However, there are valid use cases for it.
My ferris-resiste project is an RSS to email system. The system keeps track of all RSS entries it encounters to prevent emailing duplicates. However, how long do you keep this history of RSS entries? RSS data isn’t 100% reliable, so the system has its own way of determining when to delete RSS entries. Each time an RSS entry is encountered, the date it’s encountered is saved in the database. If an RSS entry isn’t encountered, that date isn’t updated. Deleting RSS entries is then a simple query which use this last encountered date to delete entries older than 6 months. If the RSS feed hasn’t had that RSS entry for the past 6 months, it’s probably safe to assume the system will not encounter it again.
This is a perfect use case for a select-for-update SQL statement. The purpose of this post is to demonstrate how a select-for-update statement works for the Apache Derby database.
Disclaimer
This post is solely informative. Critically think before using any information presented. Learn from it but ultimately make your own decisions at your own risk.
Code
Listing 1 is Java code demonstrating select-for-update for Apache Derby.
Listing 1 - Java select for update code for Apache Derby
public Optional<RssHistory> find(String feedId, String entryId) {
log.info(String.format("Find RSS entry history feedId=\"%s\", entryId=\"%s\"", feedId, entryId));
Optional<RssHistory> retval
= Optional.empty();
StringBuilder sp = new StringBuilder();
sp.append(" select ");
sp.append(" feed_id, entry_id, published_on, last_found_on ");
sp.append(" from ");
sp.append(" rss_entry_history ");
sp.append(" where ");
sp.append(" feed_id=? ");
sp.append(" and ");
sp.append(" entry_id=? ");
sp.append(" for update of ");
sp.append(" last_found_on ");
PreparedStatement stmt = null;
ResultSet rs = null;
try {
stmt = conn.prepareUpdatableStatement(sp.toString());
stmt.setString(1, feedId);
stmt.setString(2, entryId);
rs = stmt.executeQuery();
if (rs.next()) {
retval = Optional.of(
new RssHistory(feedId, feedId, rs.getTimestamp("published_on").toInstant())
);
rs.updateDate(4, Date.valueOf(LocalDate.now()));
rs.updateRow();
}
} catch (Throwable t) {
throw new RuntimeException(
String.format("Problem finding feed entry in history table feedId=\"%s\", entryId=\"%s\", sql=\"%s\""
, feedId, entryId, sp.toString()
), t
);
} finally {
conn.close(stmt, rs);
}
return retval;
}
Lines 17,18 These lines make this a select-for-update query. Line 18 specifies the last_found_on field is being updated.
Line 23 Uses the prepareUpdatableStatement() method to get a Statement object.
Line 34 Uses the updateDate() method to set the new value for the last_found_on field.
Line 35 Uses the updateRow() method to save the updated data to the database within the select-for-update and without having to execute a separate update statement.
Summary
That’s it. Pretty simple. I hope you enjoyed learning how to run a select-for-update SQL statement in Apache Derby.
This is my series on the Apache Derby Database. Move beyond its basics and use a great database for your applications.
Apache Derby Database Users and Permissions. Learn how to create users in Derby and assign them different roles and permissions. This is for security control compliance and to protect your data.
This post is solely informative. Critically think before using any information presented. Learn from it but ultimately make your own decisions at your own risk.
For my blog, since I write mostly about technology and specifically software development, I needed a syntax highlighter for styling my source code examples.
I first started using SyntaxHighlighter to style source code. SyntaxHighligher works by add a class to a <pre> tag like this:
<pre class=“brush: java”>
This worked well until I started writing my blog posts using Scrivener. With Scrivener, I write in Markdown and Scrivener compiles to HTML for me. The standard HTML to use for source code is a <pre> tag surrounding a <code> tag like this:
<pre><code class=“java”>
Unfortunately, SyntaxHighligher does not support this HTML so it no longer worked for me.
I then started using Highlight.js. This tool has been working well, but its styling is a little too simple. Plus I really wanted to start having line numbers added to my source code examples and Highlight.js does not support this.
It is time for another change. The purpose of this post is demonstrate how to incorporate the PrismJS syntax highlighting tool into Blogger.
Disclaimer
This post is solely informative. Critically think before using any information presented. Learn from it but ultimately make your own decisions at your own risk.
Requirements
I did all of the work for this post using the following major technologies. You may be able to do the same thing with different technologies or versions, but no guarantees.
Blogger
Scrivener 3
PrismJS 1.29
Download PrismJS
Visit the PrismJS download page: https://prismjs.com/download.html. On this page you are able to select the languages and plugins you want to include in your prism download. It is tempting to select everything, but, the reality is you will never use some of the languages listed. It only takes a few minutes to go through the language list and select the ones you use most often.
For PrismJS plugins, my primary reason for switching to PrismJS is the Line Numbers plugin. This is an important feature for me. I want to have line numbers added to my source code examples.
Another important plugin is the Autoloader plugin. If you try to style a language you have not previously included in your download, Autoloader will automatically get the styling for that language for you. This is good for occasional use. I would not rely on it all the time. If you start blogging about a new language regularly, re-download PrismJS with that language selected.
What is also nice about the PrismJS download page is that while you are selecting languages and plugins, the URL in your browser is automatically updated to reflect your selections. This means, once you are done selecting all the options you want, save the URL in your your favorite note-taking software (OneNote). Then all you need to do is click on the URL and you don’t have to go through selecting all your languages and plugins again. Very nice!
After you have downloaded the Prism JS and CSS files, the next thing you need to figure out is what to do with them. There are a couple options:
Cut and paste the contents inside your Blogger theme.
Host the JS and CSS files somewhere and update your Blogger template to use them.
Although option #2 is a bit more complicated, it is the better long-term option in my opinion. Blogger does not allow file uploads, so the files have to be hosted somewhere else. There are a number of different options where to host the files, but I chose to use my Microsoft OneDrive account to do this. I chose OneDrive because I already have an account, I use it all the time, and it is easy to use. Most online file upload system (Google Drive, etc.) allow you to get a read-only, permanent link to a file. That is exactly what we are going to to do.
I’m assuming you already know how to save a file on OneDrive, so I will start from there. Login to OneDrive with a web browser and navigate to the folder where you have the Prism JS and CSS files. As seen in Figure 1, you will need to click three times to generate the embedded code.
Select one of the files.
Click the “Embed” option.
Click the “Generate” button.
Figure 1 - Three Clicks to Generate Embedded Code
Three Clicks to Generate Embedded Code
Figure 2 shows an embedded code example. You will notice it is an <iframe> tag with a src attribute (and a few others). We will be concentrating on the src attribute.
Figure 2 - The iframe Embedded Code
The iframe Embedded Code
Let us take a look at the <iframe> tag a little more closely:
These URL values are the direct links to your JS file and the CSS file. Test them by pasting the URL values into a browser. The browser should download the file without redirecting to OneDrive. If it does not download directly, something is not right and you should try again.
Now that we have the direct links to the hosted JS and CSS files, let us look at how we update the Blogger theme.
Blogger Theme Updates
Now that the Prism JS and CSS files are hosted on OneDrive and I have permanent URL values to retrieve them, I now need to update my Blogger theme to use these files. I will need to make two updates to the Blogger theme:
Include both the JS and CSS files.
Add the ‘line-numbers’ class to the <body> tag.
Let us take a look at how to do both.
Include both the JS and CSS files
The JS file gets included with a <script> tag and the CS file gets included with a <link> tag. Start by creating both of these tags and drop in the permanent URL values like this:
However, your not done yet! Normally this is all you need to do, but Blogger themes have a bit of a quirk. They seem to be saved as XML so the & characters in the URL values are a problem. To successfully save these tags to the Blogger theme, you need to escape the & characters with & like this:
These tags are now ready to be used in the Blogger theme.
Add the ‘line-numbers’ class to the <body> tag
Recall that one of the reasons I am switching to Prism is because it was important to me to have line numbers added to my source code examples. This is done by the Prism Line Numbers plugin. To use this plugin, you need to do is add the ‘line-numbers’ class to the <body> tag within the Blogger theme. It looks like this:
Now let us get these updates into the Blogger theme.
Updating the Blogger Theme
After you log into your blog, perform the following steps as shown in Figures 3 and 4:
Click “Theme” on the left
Click the down-pointing arrow
Select “Edit HTML”
Figure 3 - Blogger Theme Customization
Blogger Theme Customization
Figure 4 - Blogger Edit HTML
Blogger Edit HTML
Your are now looking at the HTML template of your blog’s theme. The Prism <script> and <link> tags you created above need to go somewhere within the opening and closing <head></head> tags so it looks like this:
The update to <body> is even easier. Just search the template for “<body” and update it to include the “line-numbers” class.
NOTE
An HTML element can have multiple class values. The values are separated by a blank space. So note in the example below the blank space between loading and line-numbers.
Let us take a look at a few source code syntax highlighting examples to make sure everything is working OK.
Listing 1 - Java
package org.prism.example;
public static final void main(String [] args) {
System.out.println("Hello world!");
}
Listing 2 - JavaScript
const baseValue = prompt('Enter the base of a triangle: ');
const heightValue = prompt('Enter the height of a triangle: ');
// calculate the area
const areaValue = (baseValue * heightValue) / 2;
console.log(
`The area of the triangle is ${areaValue}`
);
DECLARE
name VARCHAR2(50);
BEGIN
name := 'Rita';
DBMS_OUTPUT.PUT_LINE('Hello, ' || name);
END;
FOR i IN 1..10 LOOP
DBMS_OUTPUT.PUT_LINE('i = ' || i);
END LOOP;
Host the downloaded JS and CSS files on the technology of your choice. My example used OneDrive. You can also use Google Drive, GitLab, AWS, Azure, and I’m sure there are others.
Include the JS and CSS files in the Blogger theme by updating the template:
