javap提供此功能，-c参数可查看字节码。例如：t.class为已编译的字节码，javap -c t可得到如下：
public static void main(java.lang.String[]);
Code:
0: iconst_1
1: istore_1
2: getstatic #2 // Field java/lang/System.out:Ljava/io/PrintStream;
5: iload_1
6: invokevirtual #3 // Method java/io/PrintStream.println:(I)V
9: return
