CCT社内勉強会用のものです

Fact.java

public class Fact {
  public static int fact(int n) {
    if(i < 0) throw new IllegalArgumentException("n must be >= 0");
    int r = 1;
    for(int i = 1; i <= n; i++) {
      r *= i;
    } 
    return r;
  }
}

HelloWorld.java

public class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello, World!");
  }
}

javap.txt

Compiled from "Fact.java"
public class Fact {
  public Fact();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static int fact(int);
    Code:
       0: iload_0
       1: ifge          14
       4: new           #2                  // class java/lang/IllegalArgumentException
       7: dup
       8: ldc           #3                  // String n must be >= 0
      10: invokespecial #4                  // Method java/lang/IllegalArgumentException."<init>":(Ljava/lang/String;)V
      13: athrow
      14: iconst_1
      15: istore_1
      16: iconst_1
      17: istore_2
      18: iload_2
      19: iload_0
      20: if_icmpgt     33
      23: iload_1
      24: iload_2
      25: imul
      26: istore_1
      27: iinc          2, 1
      30: goto          18
      33: iload_1
      34: ireturn

  public static void main(java.lang.String[]);
    Code:
       0: getstatic     #5                  // Field java/lang/System.out:Ljava/io/PrintStream;
       3: iconst_5
       4: invokestatic  #6                  // Method fact:(I)I
       7: invokevirtual #7                  // Method java/io/PrintStream.println:(I)V
      10: return
}

Compiled from "Fact.java"
public class Fact {
public Fact();
Code:
0: aload_0
1: invokespecial #1 // Method java/lang/Object."":()V
4: return

public static int fact(int);
Code:
0: iload_0
1: ifge 14
4: new #2 // class java/lang/IllegalArgumentException
7: dup
8: ldc #3 // String n must be >= 0
10: invokespecial #4 // Method java/lang/IllegalArgumentException."":(Ljava/lang/String;)V
13: athrow
14: iconst_1
15: istore_1
16: iconst_1
17: istore_2
18: iload_2
19: iload_0
20: if_icmpgt 33
23: iload_1
24: iload_2
25: imul
26: istore_1
27: iinc 2, 1
30: goto 18
33: iload_1
34: ireturn

public static void main(java.lang.String[]);
Code:
0: getstatic #5 // Field java/lang/System.out:Ljava/io/PrintStream;
3: iconst_5
4: invokestatic #6 // Method fact:(I)I
7: invokevirtual #7 // Method java/io/PrintStream.println:(I)V
10: return
}