[b]使用Java反射机制得到类的结构信息[/b]
代码如下：
package com.youdao.wm;import java.lang.reflect.Constructor;import java.lang.reflect.Field;import java.lang.reflect.Method;import java.lang.reflect.Modifier;/** * java反射机制测试：打印类的构造函数、方法、属性的信息 * * @author jacky * */public class ReflectionTest { public static void main(String[] args) { // 要打印的类名 String name = "java.lang.Double"; try { // 得到此类对应的Class Class c1 = Class.forName(name); // 得到此类的父类 Class superc1 = c1.getSuperclass(); System.out.print("class " + name); // 如果超类不为空且不是Object if (superc1 != null && superc1 != Object.class) { System.out.print("extends " + superc1.getName()); } System.out.print("\n{\n"); // 打印此类的构造函数信息 printConstructors(c1); System.out.println(); // 打印此类的方法信息 printMethods(c1); System.out.println(); // 打印此类的属性信息 printFields(c1); System.out.print("\n}\n"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /** * 打印Class对应类的构造函数信息 * * @param c1 * Class */ public static void printConstructors(Class c1) { Constructor[] constructors = c1.getDeclaredConstructors(); for (Constructor c : constructors) { String name = c.getName(); System.out.print(" " + Modifier.toString(c.getModifiers())); System.out.print(" " + name + "("); Class[] paramTypes = c.getParameterTypes(); for (int j = 0; j < paramTypes.length; j++) { if (j > 0) System.out.print(","); System.out.print(paramTypes[j].getName()); } System.out.println(");"); } } /** * 打印Class对应类的所有方法信息 * * @param c1 * Class */ public static void printMethods(Class c1) { Method[] methods = c1.getDeclaredMethods(); for (Method method : methods) { Class retType = method.getReturnType(); String name = method.getName(); System.out.print(" " + Modifier.toString(method.getModifiers())); System.out.print(" " + retType.getName() + " " + name + "("); Class[] paramTypes = method.getParameterTypes(); for (int j = 0; j < paramTypes.length; j++) { if (j > 0) System.out.print(", "); System.out.print(paramTypes[j].getName()); } System.out.println(");"); } } /** * 打印Class对应类的属性信息 * * @param c1 * Class */ public static void printFields(Class c1) { Field[] fields = c1.getDeclaredFields(); for (Field f : fields) { Class classType = f.getType(); System.out.print(" " + Modifier.toString(f.getModifiers())); System.out.print(" " + classType.getName() + " " + f.getName()); System.out.println(";\n"); } }}
