Java通過反射實現方法調用

• 代碼實現

package me.andy.practice.reflect;import org.junit.Test;import java.lang.reflect.Constructor;import java.lang.reflect.Method;import static junit.framework.Assert.assertEquals;public class MethodInvokeTest {    @Test    public void test_add() throws Exception {        Class<?> personClass = Calculate.class;        Object person = personClass.newInstance();        Method method = personClass.getDeclaredMethod("add", new Class[]{int.class, int.class});        Object result = method.invoke(person, new Object[]{1, 2});        assertEquals(result, 3);    }    @Test    public void test_subtract() throws Exception {        Class<?> personClass = Calculate.class;        Object person = personClass.newInstance();        Method method = personClass.getDeclaredMethod("subtract", new Class[]{int.class, int.class});        method.setAccessible(true);        Object result = method.invoke(person, new Object[]{2, 1});        assertEquals(result, 1);    }}class Calculate {     public int add(int a, int b) {        return a + b;    }    private int subtract(int a, int b) {        return a - b;    }}

• 代碼講解

建立對象：Object person = personClass.newInstance();

擷取方法： Method method = personClass.getMethod("add", new Class[]{int.class, int.class});

方法調用：Object result = method.invoke(person, new Object[]{1, 2});

訪問私人方法：method.setAccessible(true);