JavaFX Strings vs Java Strings

Introduction

Assateague Island Pony

One of the first things we learn in any language is outputting text such as “Hello World“. Most languages support strings (unlike C’s char array) which makes storing and outputting text easy, however dealing with strings was often painful from one language to another. I will contrast between JavaFX Strings and Java Strings to help demonstrate how using them will make your pains disappear!

High level issues that many languages encounter with Strings:

• Readability – Difficult to read when string literals are large
• Expressions – Embedded expressions in strings.
• Formatting – Formatting objects into strings

Example 1 – Readability

Often folks who have worked with JEE Web apps has one time or another has hand written JDBC code using SQL statements to run against a database. And if you have used the Java Persistence API (JPA), I’m sure you have written a named query at least once. Have you ever noticed the ugliness of string concatenation?

[Disclaimer: There are plenty of object relational persistent APIs that don’t like hand built SQLs or Bean managed persistence. Just pretend you are learning JDBC for the very first time. I’m not responsible for SQL injection hacks, so please don’t use the code below in a production system.]

Here is a Java String literal containing a SQL statement:

// Java Code
String param1 = "Carl";
String sql = "SELECT " +
                      "EMP.fname, " +
                      "EMP.lname " +
                  "FROM " +
                      "EMP " +
                  "WHERE " +
                      "EMP.fname LIKE '" + param1 + "'%";

Now let’s see how it looks in JavaFX:

// JavaFX Code
def param1 = "Carl";
var sql = "SELECT "
             "EMP.fname,"
             "EMP.lname "
          "FROM "
             "EMP "
          "WHERE "
             "EMP.fname LIKE '{param1}'%";

Note: You will notice the SQL statement has less clutter and the param1 expression is inside the last part of the where clause. Eazy peazy! The next example will be a more elaborate expression that is embedded in a string.

Example 2 – Expressions

// Java Code
public void outputTruth(boolean news) {
      //String reportNews = news ? "is":"is not"; // tiny bit cryptic
      String reportNews = null;
      if (news)
          reportNews = "is"
      else
          reportNews = "is not";
      System.out.println("The news " + reportNews + " trustworthy");
}

Let’s see the JavaFX-cellent implementation:

// JavaFX Code
public function outputTruth(news:Boolean) {
      println("The news {if (news) "is" else "is not"} trustworthy");
}

Note: An embedded expression within the curly braces will return a string object. A good rule of thumb is to keep the expressions simple.

Example 3 – Formatting

To format an String value you must first create a format object. Remember a Java java.text.Format object is not thread safe. Synchronize it or create another one.

// Java Code
Format dateFormat = new SimpleDateFormat("MM/dd/yy");
String s = formatter.format(new Date());
System.out.println(s);

Here is the JavaFX equivalent:

// JavaFX Code
var s = "{%MM/dd/yy java.util.Date{}}";
println(s);

Note: After the ‘%’ is the format specified as ‘MM/dd/yy’ then a SPACE and then the object to be formatted (Date object). To see the format pattern letters take a look at the Java Doc for SimpleDateFormat.

Conclusion

Strings in JavaFX are extremely easy to use and definitely less typing. The added clarity will help people debug better. So, Happy stringing!  Let me know what you think. Any feedback is always welcome.