How can I pad a String in Java?

Padding Techniques

String.format() for dynamic padding

Adapt the width to your needs with String.format():

int width = 15; 
// "What's your size?" Padding asks. "15," Text replies.  
String padded = String.format("%-" + width + "s", "text"); // "text            "
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Padding with specific character

Replace the 'space' in padding with any desired character:

// Who needs spaces, when you have stars!
String paddedStar = String.format("%-10s", "text").replace(' ', '*'); // "text******"
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Padding with Guava library

Marginally less pounds, but more robust with Guava library:

// When 'x' marks the start, and 'y' greets you at the end.  
String paddedStart = Strings.padStart("text", 10, 'x');  // "xxxxxxtext"
String paddedEnd = Strings.padEnd("text", 10, 'y');      // "textyyyyyy"
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Advanced Padding Techniques

Concatenation for Padding

Simple concatenation might be your cup of tea:

// When in doubt, simply pad it out! 
String rightPadded = "text" + " ".repeat(10 - "text".length()); 
String leftPadded = " ".repeat(10 - "text".length()) + "text"; 
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Enhance your Numeric Padding

Take DecimalFormat for a numeric padding spin:

// Numbers don't lie, but they love to be zero-padded!
DecimalFormat df = new DecimalFormat("0000000");
String paddedNumber = df.format(123); // "0000123"
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StringUtils for Apache Fanboys

StringUtils takes care of all your padding blues:

// StringUtils shows, it ain't just about zeros.  
String padded = StringUtils.rightPad("text", 10); 
String padded = StringUtils.leftPad("text", 10, 'z'); 
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Formatter Class

Sometimes, String.format() just isn't enough. Say hello to Formatter class:

// For when String.format() starts feeling too "Main Stream."
StringBuilder sb = new StringBuilder();
Formatter fmt = new Formatter(sb);
fmt.format("%-10s", "text"); // "text      "
String padded = sb.toString();
fmt.close();
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