sizeof.java

这是一个分布式通信程序框架源程序

package dim;

import java.lang.reflect.*;

        public class Sizeof {
        
                private static final int SZ_REF = 4;
        
                public static int sizeof(boolean b)
                {
                        return 1;
                }
        
                public static int sizeof(byte b)
                {
                        return 1;
                }
        
                public static int sizeof(char c)
                {
                        return 2;
                }
        
                public static int sizeof(short s)
                {
                        return 2;
                }
        
                public static int sizeof(int i)
                {
                        return 4;
                }
        
                public static int sizeof(long l)
                {
                        return 8;
                }
        
                public static int sizeof(float f)
                {
                        return 4;
                }
        
                public static int sizeof(double d)
                {
                        return 8;
                }
        
                private static int size_inst(Class c)
                {
                        Field flds[] = c.getDeclaredFields();
                        int sz = 0;
        
                        for (int i = 0; i < flds.length; i++) {
                                Field f = flds[i];
                                if (!c.isInterface() &&
                                    (f.getModifiers() & Modifier.STATIC) != 0)
                                        continue;
                                sz += size_prim(f.getType());
                        }
        
                        if (c.getSuperclass() != null)
                                sz += size_inst(c.getSuperclass());
        
                        Class cv[] = c.getInterfaces();
                        for (int i = 0; i < cv.length; i++)
                                sz += size_inst(cv[i]);
        
                        return sz;
                }
        
                private static int size_prim(Class t)
                { 
                        if (t == Boolean.TYPE)
                                return 1;
                        else if (t == Byte.TYPE)
                                return 1;
                        else if (t == Character.TYPE)
                                return 2;
                        else if (t == Short.TYPE)
                                return 2;
                        else if (t == Integer.TYPE)
                                return 4;
                        else if (t == Long.TYPE)
                                return 8;
                        else if (t == Float.TYPE)
                                return 4;
                        else if (t == Double.TYPE)
                                return 8;
                        else if (t == Void.TYPE)
                                return 0;
                        else
                                return SZ_REF;
                }
        
                private static int size_arr(Object obj, Class c)
                {
                        Class ct = c.getComponentType();
                        int len = Array.getLength(obj);
        
                        if (ct.isPrimitive()) {
                                return len * size_prim(ct);
                        }
                        else {
                                int sz = 0;
                                for (int i = 0; i < len; i++) {
                                        sz += SZ_REF;
                                        Object obj2 = Array.get(obj, i);
                                        if (obj2 == null)
                                                continue;
                                        Class c2 = obj2.getClass();
                                        if (!c2.isArray())
                                                continue;
                                        sz += size_arr(obj2, c2);
                                }
                                return sz;
                        }
                }
        
                public static int sizeof(Object obj)
                {
                        if (obj == null)
                                return 0;
        
                        Class c = obj.getClass();
        
                        if (c.isArray())
                                return size_arr(obj, c);
                        else
                                return size_inst(c);
                }
        
                private static void err(String s)
                {
                        System.err.println("*** " + s + " ***");
                }       
        }