Task: Word wrap
Go: package main

import (
    "fmt"
    "strings"
)

func wrap(text string, lineWidth int) (wrapped string) {
    words := strings.Fields(text)
    if len(words) == 0 {
        return
    }
    wrapped = words[0]
    spaceLeft := lineWidth - len(wrapped)
    for _, word := range words[1:] {
        if len(word)+1 > spaceLeft {
            wrapped += "\n" + word
            spaceLeft = lineWidth - len(word)
        } else {
            wrapped += " " + word
            spaceLeft -= 1 + len(word)
        }
    }
    return
}

var frog = `
In olden times when wishing still helped one, there lived a king
whose daughters were all beautiful, but the youngest was so beautiful
that the sun itself, which has seen so much, was astonished whenever
it shone in her face.  Close by the king's castle lay a great dark
forest, and under an old lime-tree in the forest was a well, and when
the day was very warm, the king's child went out into the forest and
sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this
ball was her favorite plaything.`

func main() {
    fmt.Println("wrapped at 80:")
    fmt.Println(wrap(frog, 80))
    fmt.Println("wrapped at 72:")
    fmt.Println(wrap(frog, 72))
}

Java: package rosettacode;

import java.util.StringTokenizer;

public class WordWrap 
{
    int defaultLineWidth=80;
    int defaultSpaceWidth=1;
    void minNumLinesWrap(String text)
    {
        minNumLinesWrap(text,defaultLineWidth);
    }
    void minNumLinesWrap(String text,int LineWidth)
    {
        StringTokenizer st=new StringTokenizer(text);
        int SpaceLeft=LineWidth;
        int SpaceWidth=defaultSpaceWidth;
        while(st.hasMoreTokens())
        {
            String word=st.nextToken();
            if((word.length()+SpaceWidth)>SpaceLeft)
            {
                System.out.print("\n"+word+" ");
                SpaceLeft=LineWidth-word.length();
            }
            else
            {
                System.out.print(word+" ");
                SpaceLeft-=(word.length()+SpaceWidth);
            }
        }
    }
    public static void main(String[] args)
    {
        WordWrap now=new WordWrap();
        String wodehouse="Old Mr MacFarland (_said Henry_) started the place fifteen years ago. He was a widower with one son and what you might call half a daughter. That's to say, he had adopted her. Katie was her name, and she was the child of a dead friend of his. The son's name was Andy. A little freckled nipper he was when I first knew him--one of those silent kids that don't say much and have as much obstinacy in them as if they were mules. Many's the time, in them days, I've clumped him on the head and told him to do something; and he didn't run yelling to his pa, same as most kids would have done, but just said nothing and went on not doing whatever it was I had told him to do. That was the sort of disposition Andy had, and it grew on him. Why, when he came back from Oxford College the time the old man sent for him--what I'm going to tell you about soon--he had a jaw on him like the ram of a battleship. Katie was the kid for my money. I liked Katie. We all liked Katie.";
        System.out.println("DEFAULT:");
        now.minNumLinesWrap(wodehouse);
        System.out.println("\n\nLINEWIDTH=120");
        now.minNumLinesWrap(wodehouse,120);
    }

}