Since Groovy 4 we can parse TOML configuration data into a Map. Once the TOML data is transformed into the Map we can use all possibilities in Groovy to lookup keys and their values in maps. For example we can use GPath expressions to easily get the value of a (nested) key. To parse TOML configuration data we must use the TomlSlurper class that is in the groovy.toml package. We can use the parse method when we have a file, reader or stream with our configuration. To parse a String value with TOML configuration we use the parseText method.

Unfortunately Oracle databases aren’t compatible with the new Apple Silicon CPU architecture. Due to this fact you’re not able to run an Oracle XE image with TestContainers on your brand-new MacBook, but there’s a workaround!

TLDR;

Unfortunately Oracle databases aren’t compatible with the new Apple Silicon CPU architecture. Due to this fact you’re not able to run an Oracle XE database on your brand-new MacBook, but there’s a workaround!

TLDR;

GINQ (Groovy-INtegrated Query) is added since Groovy 4. With GINQ we can query in-memory collections with SQL like statements. If we want to get the row numbers for each row in the query result set we can use the implicit variable _rn. We must specify _rn in the select expression of our GINQ query. We can even use as to give it a meaningful name in the result set.

Groovy supports more classifiers for a switch case statement than Java. Since Groovy 4 we can use switch also as an expression. This means the switch statement returns a value without having to use return. Instead of using a colon (:) and break we use the → notation for a case. We specify the value that the switch expressions returns after →. When we need a code block we simply put the code between curly braces ({…​}).

The dw::core::Strings has a lot of functions to deal with strings. One of the functions is ordinalize that takes a number as argument and returns the ordinal value as string.

To check if a value is of a certain type in DataWeave we must use the is operator. We must specify the type after the is operator and the value before the is operator. For example to check if the value 42 is a Number we write 42 is Number. The result is a Boolean that is either true or false. In the previous example the result is true.

To calculate the modulo of two numbers in DataWeave we can use the mod function from the dw::Core module. We provide two arguments where the first argument is the number that needs to be divided by the number provided as second argument. The number that remains after a division of the input arguments is returned as a result.

In a previous blog post we learned about the zip function. DataWeave also gives us the unzip function that will do the opposite for an array with arrays. The input argument of the unzip function is an array where the elements are also arrays. This could be created by the zip function or just defined as data structure directly. The unzip function will take from each array the same index element and return it as an array with the index elements. For example with the input array [[1, "A"], [2, "B"]] will be unzipped to [[1, 2], ["A", "B"]]. When the number of elements in the arrays that need to unzipped are not equal, the unzip function will only return the elements from the index with the most elements.

DataWeave has a zip function in the dw::Core module. The function will merge two arrays into a new array. Each element in the new array is also an array and will have a value from the two original arrays from the same index grouped together. So for example we have an input array ["A", "B"] and another input array [1, 2]. The result of the zip function will be [["A", 1], ["B", 2]]. The size of the resulting array is the same as the minimal size of both input arrays. Any value from an array that cannot be merged is simply ignored and left out of the resulting array.