java反射机制调用方法及简易封装工具类

import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; public class Test { public static void main(String[] args) { try { Class<?> clazz = Class.forName("com.lgz.Test"); Method method = clazz.getMethod("run"); method.invoke(clazz.newInstance()); Method methodPrivate = clazz.getDeclaredMethod("eat"); methodPrivate.setAccessible(true);//调private方法 methodPrivate.invoke(clazz.newInstance()); Method methodStatic = clazz.getMethod("work"); methodStatic.invoke(null); Method method1 = clazz.getMethod("speak", int.class, String.class); method1.invoke(clazz.newInstance(), 22, "小明"); } catch (ClassNotFoundException | NoSuchMethodException | IllegalAccessException | InstantiationException | InvocationTargetException e) { e.printStackTrace(); } } public static void work() { System.out.println("work() 方法被调用..."); } private void eat() { System.out.println("eat() 方法被调用..."); } public void run() { System.out.println("run() 方法被调用..."); } public void speak(int age, String name) { System.out.println("speak() 方法被调用.... age = " + age + " name= " + name); } }

工具类：

import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; public class RefUtil { public static <T> T execute(Class<?> clazz, Object obj, String methodName) { try { Method method = clazz.getMethod(methodName); return method == null ? null : (T) method.invoke(obj); } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) { e.printStackTrace(); return null; } } public static <T> T executePrivate(Class<?> clazz, Object obj, String methodName) { try { Method methodPrivate = clazz.getDeclaredMethod(methodName); methodPrivate.isAccessible(); methodPrivate.setAccessible(true);//调private方法 return (T) methodPrivate.invoke(obj); } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) { e.printStackTrace(); return null; } } public static <T> T execute(Class<?> objclass, Object obj, String methodName, T value) { try { if (value == null) return null; Method func = objclass.getMethod(methodName, value.getClass()); if (func != null) { return (T) func.invoke(obj, value); } else { return null; } } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) { e.printStackTrace(); return null; } } public static <T> T executeInt(Class<?> objclass, Object obj, String methodName, int value) { try { Method func = objclass.getMethod(methodName, int.class); Test.p(func.getClass()); return (T) func.invoke(obj, value); } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) { e.printStackTrace(); return null; } } public static <T> T executeDouble(Class<?> objclass, Object obj, String methodName, double value) { try { Method func = objclass.getMethod(methodName, double.class); return (T) func.invoke(obj, value); } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) { e.printStackTrace(); return null; } } public static <T> T executeFloat(Class<?> objclass, Object obj, String methodName, float value) { try { Method func = objclass.getMethod(methodName, float.class); return (T) func.invoke(obj, value); } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) { e.printStackTrace(); return null; } } public static <T> T executeLong(Class<?> objclass, Object obj, String methodName, long value) { try { Method func = objclass.getMethod(methodName, long.class); return (T) func.invoke(obj, value); } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) { e.printStackTrace(); return null; } } }