Chaining.bytecode

  public java.lang.String concatenationWithExtraVar();
    Code:
       0: new           #8                  // class java/lang/StringBuilder
       3: dup
       4: invokespecial #9                  // Method java/lang/StringBuilder."<init>":()V
       7: aload_0
       8: getfield      #3                  // Field a1:Ljava/lang/String;
      11: invokevirtual #10                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      14: aload_0
      15: getfield      #5                  // Field a2:Ljava/lang/String;
      18: invokevirtual #10                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      21: aload_0
      22: getfield      #7                  // Field a3:Ljava/lang/String;
      25: invokevirtual #10                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      28: invokevirtual #11                 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
      31: astore_1
      32: aload_1
      33: areturn

  public java.lang.String concatenationWithoutExtraVar();
    Code:
       0: new           #8                  // class java/lang/StringBuilder
       3: dup
       4: invokespecial #9                  // Method java/lang/StringBuilder."<init>":()V
       7: aload_0
       8: getfield      #3                  // Field a1:Ljava/lang/String;
      11: invokevirtual #10                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      14: aload_0
      15: getfield      #5                  // Field a2:Ljava/lang/String;
      18: invokevirtual #10                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      21: aload_0
      22: getfield      #7                  // Field a3:Ljava/lang/String;
      25: invokevirtual #10                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      28: invokevirtual #11                 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
      31: areturn

Chaining.java

public class Chaining {

    private String a1 = "111111111111111111111111";
    private String a2 = "222222222222222222222222";
    private String a3 = "333333333333333333333333";

    public String typicalChaining() {
        return new StringBuilder().append(a1).append(a2).append(a3).toString();
    }

    public String noChaining() {
        StringBuilder sb = new StringBuilder();
        sb.append(a1);
        sb.append(a2);
        sb.append(a3);
        return sb.toString();
    }

    public String concatenationWithExtraVar() {
        String result = a1 + a2 + a3;
        return result;
    }

    public String concatenationWithoutExtraVar() {
        return a1 + a2 + a3;
    }
}