Class alunbarClass1 = Class.forName("cn.javaguide.TargetObject");

package cn.javaguide;

public class TargetObject {
  private String value;

  public TargetObject() {
    value = "JavaGuide";
  }

  public void publicMethod(String s) {
    System.out.println("I love " + s);
  }

  private void privateMethod() {
    System.out.println("value is " + value);
  }
}

package cn.javaguide;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class Main {
  public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InstantiationException, InvocationTargetException, NoSuchFieldException {
    /**
     * 獲取TargetObject類的Class對象并且創(chuàng)建TargetObject類實(shí)例
     */
    Class<?> tagetClass = Class.forName("cn.javaguide.TargetObject");
    TargetObject targetObject = (TargetObject) tagetClass.newInstance();
    /**
     * 獲取所有類中所有定義的方法
     */
    Method[] methods = tagetClass.getDeclaredMethods();
    for (Method method : methods) {
      System.out.println(method.getName());
    }
    /**
     * 獲取指定方法并調(diào)用
     */
    Method publicMethod = tagetClass.getDeclaredMethod("publicMethod",
        String.class);

    publicMethod.invoke(targetObject, "JavaGuide");
    /**
     * 獲取指定參數(shù)并對參數(shù)進(jìn)行修改
     */
    Field field = tagetClass.getDeclaredField("value");
    //為了對類中的參數(shù)進(jìn)行修改我們?nèi)∠踩珯z查
    field.setAccessible(true);
    field.set(targetObject, "JavaGuide");
    /**
     * 調(diào)用 private 方法
     */
    Method privateMethod = tagetClass.getDeclaredMethod("privateMethod");
    //為了調(diào)用private方法我們?nèi)∠踩珯z查
    privateMethod.setAccessible(true);
    privateMethod.invoke(targetObject);
  }
}