Java Stringbuilder实现void方法

Question

I am confused about StringBUilder.append(). Netbeans say that void type not allowed.

Here is the the my Java class named Levencthein.java

 public void printDistance(String s1, String s2) {
    System.out.println( computeEditDistance(s1, s2) + " ("+similarity(s1, s2) * 100 +")");
}

now, in the other class, assumpted in b.java

StringBuilder s = new StringBuilder();
for (final JCCDFile file : files) {

        LevenshteinDistance lv = new LevenshteinDistance();
        if (idLexerSelection != getIDLexer()) {
            System.out.println(temp.getName() + " ==> " + file.getName());

            s.append(lv.printDistance(name1, name2)); This is the error


            sb.append(file.getName());
        }
    }

any solution ?

Answer 1

You are attempting to append the return value of printDistance , but there is no return value because it's void . In printDistance , instead of printing the value, return it.

return computeEditDistance(s1, s2) + " ("+similarity(s1, s2) * 100 +")";

Answer 2

You cannot append the void return of printDistance to a StringBuilder (as the compiler is telling you). If I understand you, then this

public void printDistance(String s1, String s2) {
  System.out.println( computeEditDistance(s1, s2) 
      + " ("+similarity(s1, s2) * 100 +")");
}

Should return String and I'd return String.format like

public void printDistance(String s1, String s2) {
  return String.format("%s (%s)", computeEditDistance(s1, s2), 
      similarity(s1, s2) * 100);
}

Assuming that computeEditDistance() and similarity() return String . If they return int replace the %s in format with %d (or %f for floating point).