Posts by Hubert Klein Ikkink

Groovy Goodness: For Loops With Index Variable

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Hubert Klein Ikkink

Groovy 5 adds support for using an index variable in a for-in loop. You must define an extra variable as first argument of the for loop. This variable will be used as index variable. For each iteration of the code in the for-in loop the value of this index variable is incremented by 1. You can use this value in the for loop.

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Groovy Goodness: Create Ascii Bar Charts

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Hubert Klein Ikkink

Groovy 5 adds a new utility method to create an ascii bar chart. You can use the bar method in the org.codehaus.groovy.util.StringUtil class. You can pass a value, a minimum and maximum value and optinally specify the width of the bar chart. The result is a String value consisting of a number of "blocks". A block could be whole, but also 1/8 eights of the block are used to get a nice looking bar chart. How many of these values are needed is based on the input arguments. With this method you have a nice way to format number values on a command-line.

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Groovy Goodness: Transform Iterable Into A Map

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Hubert Klein Ikkink

Groovy 5 introduced some extra overloaded methods for the collectEntries method, that can be used to transform an iterable object into a Map. You can now pass a closure or function as arguments to transform the original iterable element into the key and value for the resulting Map. It is now also possible to pass a so-called collector Map that will be used to extend with new key/value pairs.

Besides extra overloaded method signatures for collectEntries Groovy 5 also adds the new methods withCollectedKeys and withCollectedValues. With the method withCollectedKeys a closure or function can passed to create the keys for the new Map based on the elements from the iterable. The value of the key/value pair is the unchanged element. You use the method withCollectedValues to pass a closure or function to create the value for the new key/value pair in the resulting Map. The key will be the original element from the iterable.

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Nushell Niceties: Filtering Null And Empty Values

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Hubert Klein Ikkink

Nushell has very useful commands to filter lists and tables. When you have a list with null values, you can use the compact command to filter out the null values. With the option --empty you can also filter out empty items like empty strings, empty lists and empty records. If you want to filter out rows in a table where a column contains a null value, you can use the compact command followed by the name of the column.

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Nushell Niceties: Rolling Dice

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Hubert Klein Ikkink

Nushell has some nice built-in commands to get randomized data. The random command can be used to get random numbers, strings, and more. You can use the dice subcommand to get random numbers between 1 and 6. The command returns a list of integers. With the option --dice you can specify how many times to throw the dice. By default the dice has 6 sides, but you can use the option --sides to change that. You could roll a dice with 2 sides, like flipping a coin, or roll a dice with 10 sides.

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Nushell Niceties: Using Request Headers With HTTP Commands

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Hubert Klein Ikkink

The nice thing about the http command in Nushell is that you can interact with HTTP endpoints without the need to install any external tools. You can use several subcommands like get, post, put, delete and patch. Each of these commands has the options to specify request headers. You can use the option --headers or the short version -H followed by a list of header keys and values.

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Nushell Niceties: Posting JSON to an HTTP Endpoint

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Hubert Klein Ikkink

The http command in Nushell can be used to interact with HTTP endpoints. You can post data to an endpoint using the post subcommand. If you want to post JSON data than you can simply use a record data structure and use the argument --content-type application/json (or the shorthand -t application/json). Nushell will automatically convert the record data structure to JSON and use it as the body of the HTTP request.

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Nushell Niceties: Getting The HTTP Response Status

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Hubert Klein Ikkink

Nushell has a built-in command to invoke HTTP requests: http. You don’t need an external tool like curl or httpie to make HTTP requests. There a lot of options to use with the http command. One of them is the --full or shorter -f option to return a table with extra details of the HTTP request and response. The request and response headers, the body and status are returned in the table. You can easily get information from the table with all the default selection options for a table structure.

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SDKMAN! Listing And Upgrading Outdated SDKs And Tools

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Hubert Klein Ikkink

SDKMAN! is as powerful tool to install and manage software development kits (SDKs) and tools, like Java, Groovy, Gradle, Maven, Spring Boot and Quarkus. If you want to see if a new version of a SDK or tool is available, you can use the sdk upgrade command. This command will list all outdated SDKs and tools. The installed version and the latest version are shown for each SDK and tool. To see if a single SDK or tool is outdated, you can use the name of the SDK or tool as argument to the sdk upgrade command.

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