Given a string in Java, just take the first X letters.

Question

Is there something like a C# Substring for Java? I'm creating a mobile application for Blackberry device and due to screen constraints I can only afford to show 13 letters plus three dots for an ellipsis.

Any suggestion on how to accomplish this?

I need bare bones Java and not some fancy trick because I doubt a mobile device has access to a complete framework. At least in my experience working with Java ME a year ago.

Answer 1

String foo = someString.substring(0, Math.min(13, someString.length()));

Answer 2

You can do exactly what you want with String.substring().

String str = "please truncate me after 13 characters!";
if (str.length() > 16)
    str = str.substring(0, 13) + "..."

Answer 3

Whenever there is some operation that you would think is a very common thing to do, yet the Java API requires you to check bounds, catch exceptions, use Math.min(), etc. (i.e. requires more work than you would expect), check Apache's commons-lang. It's almost always there in a more concise format. In this case, you would use StringUtils#substring which does the error case handling for you. Here's what it's javadoc says:

Gets a substring from the specified String avoiding exceptions.

A negative start position can be used to start n characters from the end of the String.

A null String will return null. An empty ("") String will return "".

 StringUtils.substring(null, *)   = null
 StringUtils.substring("", *)     = ""
 StringUtils.substring("abc", 0)  = "abc"
 StringUtils.substring("abc", 2)  = "c"
 StringUtils.substring("abc", 4)  = ""
 StringUtils.substring("abc", -2) = "bc"
 StringUtils.substring("abc", -4) = "abc"