Formatting strings in java

Question

I am reading the serial buffer with readLine() method. The string returned by readLine() is in the format "str1 : str2". In a while loop when I use readLine() number of times for a response of serial port command I get weird output like this :

String1 : string1
SString11 : String2
StringString2 : String23 
String4 : String5

But I need the output formatted as below

String1       : string1
SString11     : String2
StringString2 : String23 
String4       : String5

I used the split method on string and get the two strings separated with delimiter as ':'. But now I need to append the String1 with spaces to align all the colons.

I am sorry If my problem explanation is weird. But If anybody understood the problem can you please suggest how to do it?

Answer 1

Take a look at System.out.printf

Answer 2

The easiest way to achieve this is to use System.out.format(). This lets you use C printf style format specifiers. An example:

System.out.format("%-5s:%10s\n", "Name", "Nemo");
System.out.format("%-5s:%10d\n", "Age", 120);

This will output:

Name :      Nemo
Age  :       120

Also see documentation for the Formatter class to learn more about the format string syntax.

Answer 3

System.out.format("%30s : %s", str1, str2);

Will print the first string with a fixed width of 30 characters.