Question

I’m using StringBuffer in Java to concat strings together, like so:

StringBuffer str = new StringBuffer();  str.append('string value'); 

I would like to know if there’s a method (although I didn’t find anything from a quick glance at the documentation) or some other way to add ‘padding’.

Let me explain; every time I append something to the string, I want to add a space in the end, like so:

String foo = 'string value'; str.append(foo + ' '); 

and I have several calls to append.. and every time, I want to add a space. Is there a way to set the object so that it will add a space automatically after each append?

EDIT —

String input StringBuffer query = new StringBuffer(); Scanner scanner = new Scanner(System.in); scanner.UseDelimiter('\n');  do {    System.out.println('sql> ');     input = scanner.next();     if (!empty(input)) query.append(input);     if (query.toString().trim().endsWith(';')) {          //run query    } } while (!input.equalsIgnoreCase('exit'); 

I’ll use StringBuilder though as grom suggested, but that’s how the code looks right now

Answer 1

I think this is handled easier either with a helper method (untested code):

public String myMethod() {     StringBuilder sb = new StringBuilder();     addToBuffer(sb, 'Hello').addToBuffer('there,');     addToBuffer(sb, 'it').addToBuffer(sb, 'works'); }  private StringBuilder addToBuffer(StringBuilder sb, String what) {     return sb.append(what).append(' ');  // char is even faster here! ;) } 

Or even using a Builder pattern with a fluent interface (also untested code):

public String myMethod() {     SBBuilder builder = new SBBuilder()         .add('Hello').add('there')         .add('it', 'works', 'just', 'fine!');      for (int i = 0; i < 10; i++) {         builder.add('adding').add(String.valueOf(i));     }      System.out.println(builder.build()); }  public static class SBBuilder {     private StringBuilder sb = new StringBuilder();      public SBBuilder add(String... parts) {         for (String p : parts) {             sb.append(p).append(' '); // char is even faster here! ;)         }         return this;     }      public String build() {         return sb.toString();     } } 

Here’s an article on the subject.

Hope it helps! 🙂