CODEWITHSUNDEEP
javaregex
user900721
user900721

Reputation: 1437

Need help in Regular expression

I have input like "Varchar(10), Number(10), datetime(8), varchar(17), char(3) at a time one.

I need to extract only text from it. How can I do it in Java?

Lets say I have input Varchar(50) and expecting output Varchar.

I tried this, but it did not work:

String line = "varchar(0)";
String pattern = "\\D{.*}";
// Create a Pattern object 
Pattern r = Pattern.compile(pattern);
// Now create matcher object. 
Matcher m = r.matcher(line); 
if (m.find( )) { 
  System.out.println("Found value: " + m.group(0) ); 
} else { 
  System.out.println("NO MATCH"); 
}

Upvotes: 2

Views: 480

Answers (4)

Callie J
Callie J

Reputation: 31296

I think a regular expression is overkill if you're only dealing with single appearences.

For example:

s = val.substring(1, val.indexOf ('('))

would do the job. Although this would always expect to see '(' as part of the input string.

Upvotes: 0

xagyg
xagyg

Reputation: 9711

line.replaceAll("\\([^\\)]*\\)","");

Upvotes: 0

djjeck
djjeck

Reputation: 1840

Your group regular expression is in general

\w+\(\d+\)

and to capture the first part, you can make it into a group

(\w+)\(\d+\)

Try this function:

private final Pattern TYPE_REGEX = Pattern.compile("(\\w+)\\(\\d+\\)");

public String extractType(String item) {
  Matcher matcher = TYPE_REGEX.matcher(item.trim());
  if(!matcher.matches())
    return null;
  return matcher.group(1);
}

Freebie:

You might also use a typesafe enum, for your return type, as I think you're dealing with a fixed set of database types

private enum Type { VARCHAR, NUMBER, DATETIME, CHAR, ADD_ALL_OTHERS_THAT_APPLY }
private final Pattern TYPE_REGEX = Pattern.compile("(\\w+)\\(\\d+\\)");

public Type extractType(String item) {
  Matcher matcher = TYPE_REGEX.matcher(item.trim());
  if(!matcher.matches())
    return null;
  return Type.valueOf(matcher.group(1).toUpperCase());
}

Upvotes: 2

Juvanis
Juvanis

Reputation: 25950

You can split your input string with this regex "\\(\\d+\\),*":

Sample code:

String str = "Varchar(10), Number(10), datetime(8), varchar(17), char(3)";
String[] parts = str.split("\\(\\d+\\),*");

for (String part : parts)
    System.out.println(part.trim());

Output (Note that trim() is invoked before printing an element.):

Varchar
Number
datetime
varchar
char

Upvotes: 0

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