How to extract multiple string part from string in scala?-CodePudding

I have string in which I have to get some string and store it in variable.

data source=local/SQL,1433;initial catalog=Employee;user id=user_first;password=abc@123;encrypt=true;connectretrycount=3;connection timeout=30;

I need to extract data source , initial catlog,user id and password . And store it in variable. I was trying to convert it into list and iterating over it and extracting string. But that is not feasible I guess.

I want to save that value into variable like

val source = "local/SQL"

val catlog = "Employee"

Is there any other method which I can follow?

CodePudding user response：

What do you mean by "it's not feasible"? It works just fine:

// s is the same string you provided
s.split(";").map { keyVal => 
  val Array(key, value, _*) = keyVal.split("=", 2)
  key -> value
} 

// result -> 
res2: Array[(String, String)] = Array(
  ("data source", "local/SQL,1433"),
  ("initial catalog", "Employee"),
  ("user id", "user_first"),
  ("password", "abc@123"),
  ("encrypt", "true"),
  ("connectretrycount", "3"),
  ("connection timeout", "30")
)

And easily use this as a udf. Or you might prefer using regular expressions:

val extractorPattern = "data source=([^;]*);initial catalog=([^;]*);.*".r
// expand this for other fields as well


val extractorPattern(dataSource, initialCatalog) = s
// The result in ammonite:
// dataSource: String = "local/SQL,1433"
// initialCatalog: String = "Employee"

There are also some other approaches, you can also take the regex and use it in spark API functions.

Update

If you want to access it as a variable inside the function, you can do it in a safe way:

val dataSource = res2.collectFirst { case ("data source", dataSource) => dataSource } 

// dataSource: Option[String] = Some(value = "local/SQL,1433")

Or if you're sure that data source or basically any key always exists in the original string, then:

val Some(dataSource) = res2.collectFirst { case ("data source", dataSource) => dataSource } 
// dataSource: String = "local/SQL,1433"