二级JAVA南开100题1

import java.lang.reflect.*; public class exam_22 { public static void main(String[] args) throws ClassNotFoundException { if(args.length<1){ System.out.println("请输入类的名称！"); return; } __________ c = Class.forName(args[0]); print_class(c); } public static void print_class(Class c) { if (c.isInterface()) { System.out.print(Modifier.toString(c.getModifiers()) + " " + typename(c)); } else if (c.getSuperclass() != null) { System.out.print(Modifier.toString(c.getModifiers()) + " class " + typename(c) + " extends " + typename(c.getSuperclass())); } else { System.out.print(Modifier.toString(c.getModifiers()) + " class " + typename(c)); } Class[] interfaces = c.getInterfaces(); if ((interfaces != null)&& (interfaces.length > 0)) { if (c.isInterface()) System.out.print(" extends "); else System.out.print(" implements "); for(int i = 0; i < interfaces.length; i++) { if (i > 0) System.out.print(", "); System.out.print(typename(interfaces[i])); } } System.out.println(" {"); System.out.println(" // Constructors"); Constructor[] constructors = c.getDeclaredConstructors(); for(int i = 0; i < constructors.length; i++) print_method_or_constructor(constructors[i]); System.out.println(" // Fields"); Field[] fields = c.getDeclaredFields(); for(int i = 0; i < fields.length; i++) print_field(fields[i]); System.out.println(" // Methods"); __________ = c.getDeclaredMethods(); for(int i = 0; i < methods.length; i++) print_method_or_constructor(methods[i]); System.out.println("}"); } public static String typename(Class t) { String brackets = ""; while(t.isArray()) { brackets += "[]"; t = t.getComponentType(); } String name = t.getName(); int pos = name.lastIndexOf('.'); if (pos != -1) name = name.substring(pos+1); return name + brackets; } public static String modifiers(int m) { if (m == 0) return ""; else return Modifier.toString(m) + " "; } public static void print_field(Field f) { System.out.println(" " + modifiers(f.getModifiers()) + typename(f.getType()) + " " + f.getName() + ";"); } public static void print_method_or_constructor(Member member) { Class returntype=null, parameters[], exceptions[]; if (member instanceof Method) { Method m = (Method) member; returntype = m.getReturnType(); parameters = m.getParameterTypes(); exceptions = m.getExceptionTypes(); System.out.print(" " + modifiers(member.getModifiers()) + typename(returntype) + " " + member.getName() + "("); } else { Constructor c = (Constructor) member; parameters = c.getParameterTypes(); exceptions = c.getExceptionTypes(); System.out.print(" " + modifiers(member.getModifiers()) + typename(c.getDeclaringClass()) + "("); } for(int i = 0; i < parameters.length; i++) { if (i > 0) System.out.print(", "); System.out.print(typename(parameters[i])); } System.out.print(")"); if (exceptions.length > 0) System.out.print(" throws "); for(int i = 0; i < exceptions.length; i++) { if (i > 0) System.out.print(", "); System.out.print(typename(exceptions[i])); } System.out.println(";"); } }