原 Java反射的一个经典例子

学习Java反射的一个例子，具体看下面。

见以下代码：

public class ReflectTester
{
 // 该方法实现对Customer对象的拷贝操作
 public Object copy(Object object) throws Exception
 {
  Class<?> classType = object.getClass();
  Object objectCopy = classType.getConstructor(new Class[] {})
    .newInstance(new Object[] {});
  // 获得对象的所有成员变量
  Field[] fields = classType.getDeclaredFields();
  for (Field field : fields)
  {
   String name = field.getName();
   // 将属性的首字母转换为大写
   String firstLetter = name.substring(0, 1).toUpperCase();
   String getMethodName = "get" + firstLetter + name.substring(1);
   String setMethodName = "set" + firstLetter + name.substring(1);
   Method getMethod = classType.getMethod(getMethodName,
     new Class[] {});
   Method setMethod = classType.getMethod(setMethodName,
     new Class[] { field.getType() });
   Object value = getMethod.invoke(object, new Object[] {});
   setMethod.invoke(objectCopy, new Object[] { value });
  }
  // 以上两行代码等价于下面一行
  // Object obj2 = classType.newInstance();
  // System.out.println(obj);
  return objectCopy;
 }
 public static void main(String[] args) throws Exception
 {
  Customer customer = new Customer("Tom", 20);
  customer.setId(1L);
  ReflectTester test = new ReflectTester();
  Customer customer2 = (Customer) test.copy(customer);
  System.out.println(customer2.getId() + "," + customer2.getName() + ","
    + customer2.getAge());
 }
}



class Customer
{
 private Long id;
 private String name;
 private int age;
 public Customer()
 {
 }
 public Customer(String name, int age)
 {
  this.name = name;
  this.age = age;
 }
 public Long getId()
 {
  return id;
 }
 public void setId(Long id)
 {
  this.id = id;
 }
 public String getName()
 {
  return name;
 }
 public void setName(String name)
 {
  this.name = name;
 }
 public int getAge()
 {
  return age;
 }
 public void setAge(int age)
 {
  this.age = age;
 }
}

public static void main(String[] args) throws Exception
 {
  Private2 p = new Private2();

  Class<?> classType = p.getClass();

  Field field = classType.getDeclaredField("name");

  field.setAccessible(true);//压制Java对访问修饰符的检查

  field.set(p, "lisi");

  System.out.println(p.getName());
 }

原文链接：Java反射的一个经典例子，转载请注明来源！