Assembly Language for Beginners

4.1. JAVA

3: bipush 123

5: istore_2

6: getstatic #3 // Field java/lang/System.out:Ljava/io/PrintStream;

9: new #4 // class java/lang/StringBuilder

12: dup

13: invokespecial #5 // Method java/lang/StringBuilder."<init>":()V

16: ldc #6 // String s=

18: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String⤦

Ç;)Ljava/lang/StringBuilder;

21: aload_1

22: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String⤦

Ç;)Ljava/lang/StringBuilder;

25: ldc #8 // String n=

27: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String⤦

Ç;)Ljava/lang/StringBuilder;

30: iload_2

31: invokevirtual #9 // Method java/lang/StringBuilder.append:(I)Ljava/lang/⤦

ÇStringBuilder;

34: invokevirtual #10 // Method java/lang/StringBuilder.toString:()Ljava/lang/⤦

ÇString;

37: invokevirtual #11 // Method java/io/PrintStream.println:(Ljava/lang/String;)V

40: return

4.1.15 Exceptions.

Let’s rework ourMonthexample (4.1.13 on page 681) a bit:

Listing 4.10: IncorrectMonthException.java

public class IncorrectMonthException extends Exception
{
private int index;

public IncorrectMonthException(int index)
{
this.index = index;
}
public int getIndex()
{
return index;
}
}

Listing 4.11: Month2.java

class Month2
{
public static String[] months =
{
"January",
"February",
"March",
"April",
"May",
"June",
"July",
"August",
"September",
"October",
"November",
"December"
};

public static String get_month (int i) throws IncorrectMonthException

{

if (i<0 || i>11)

throw new IncorrectMonthException(i);

return months[i];